| integration over multiple timescales in primary auditory cortex. | speech and other natural vocalizations are characterized by large modulations in their sound envelope. the timing of these modulations contains critical information for discrimination of important features, such as phonemes. we studied how depression of synaptic inputs, a mechanism frequently reported in cortex, can contribute to the encoding of envelope dynamics. using a nonlinear stimulus-response model that accounted for synaptic depression, we predicted responses of neurons in ferret primary ... | 2013 | 24305812 |
| cross-modal plasticity results in increased inhibition in primary auditory cortical areas. | loss of sensory input from peripheral organ damage, sensory deprivation, or brain damage can result in adaptive or maladaptive changes in sensory cortex. in previous research, we found that auditory cortical tuning and tonotopy were impaired by cross-modal invasion of visual inputs. sensory deprivation is typically associated with a loss of inhibition. to determine whether inhibitory plasticity is responsible for this process, we measured pre- and postsynaptic changes in inhibitory connectivity ... | 2013 | 24288625 |
| nonsurgical management of hyperadrenocorticism in ferrets. | several medical therapeutic options are available for the management of the clinical signs of adrenal disease in ferrets. many of these medical modalities seem to be well tolerated and are a suitable alternative to adrenalectomy, especially for ferrets that are not surgical candidates. however, drugs that are currently available only manage the symptoms and do not provide a cure for the diseased adrenal gland, which may continue to enlarge. the medical management of urinary obstruction caused by ... | 2014 | 24274921 |
| constructing noise-invariant representations of sound in the auditory pathway. | identifying behaviorally relevant sounds in the presence of background noise is one of the most important and poorly understood challenges faced by the auditory system. an elegant solution to this problem would be for the auditory system to represent sounds in a noise-invariant fashion. since a major effect of background noise is to alter the statistics of the sounds reaching the ear, noise-invariant representations could be promoted by neurons adapting to stimulus statistics. here we investigat ... | 2013 | 24265596 |
| behavioural sensitivity to binaural spatial cues in ferrets: evidence for plasticity in the duplex theory of sound localization. | for over a century, the duplex theory has guided our understanding of human sound localization in the horizontal plane. according to this theory, the auditory system uses interaural time differences (itds) and interaural level differences (ilds) to localize low-frequency and high-frequency sounds, respectively. whilst this theory successfully accounts for the localization of tones by humans, some species show very different behaviour. ferrets are widely used for studying both clinical and fundam ... | 2014 | 24256073 |
| btbd3 controls dendrite orientation toward active axons in mammalian neocortex. | experience-dependent structural changes in the developing brain are fundamental for proper neural circuit formation. here, we show that during the development of the sensory cortex, dendritic field orientation is controlled by the btb/poz domain-containing 3 (btbd3). in developing mouse somatosensory cortex, endogenous btbd3 translocated to the cell nucleus in response to neuronal activity and oriented primary dendrites toward active axons in the barrel hollow. btbd3 also directed dendrites towa ... | 2013 | 24179155 |
| use of recombinant human thyroid-stimulating hormone for thyrotropin stimulation testing in euthyroid ferrets. | to evaluate the effects of im administration of recombinant human thyroid-stimulating hormone (rhtsh) on plasma total thyroxine (t4) concentrations in euthyroid ferrets. | 2013 | 24171372 |
| targeted disruption of layer 4 during development increases gabaa receptor neurotransmission in the neocortex. | cortical dysplasia (cd) associates with clinical pathologies, including epilepsy and mental retardation. cd results from impaired migration of immature neurons to their cortical targets, leading to clustering of neural cells and changes in cortical properties. we developed a cd model by administering methylazoxymethanol (mam), an anti-mitotic, to pregnant ferrets on embryonic day 33; this leads to reduction in cortical thickness in addition to redistribution and increased expression of gabaa rec ... | 2014 | 24155012 |
| natural and lesion-induced decrease in cell proliferation in the medial nucleus of the trapezoid body during hearing development. | the functional interactions between neurons and glial cells that are important for nervous system function are presumably established during development from the activity of progenitor cells. in this study we examined proliferation of progenitor cells in the medial nucleus of the trapezoid body (mntb) located in the rat auditory brainstem. we performed dna synthesis labeling experiments to demonstrate changes in cell proliferation activity during postnatal stages of development. an increase in c ... | 2014 | 24115041 |
| distribution and size of mucous glands in the ferret tracheobronchial tree. | a transgenic ferret model of cystic fibrosis has recently been generated. it is probable that malfunction of airway mucous glands contributes significantly to the airway pathology of this disease. the usefulness of the ferret model may therefore depend in part on how closely the airway glands of ferrets resemble those of humans. here, we show that in the ferret trachea glands are commonest in its most ventral aspect and disappear about half way up the lateral walls; they are virtually absent fro ... | 2013 | 24106034 |
| mechanisms for stable, robust, and adaptive development of orientation maps in the primary visual cortex. | development of orientation maps in ferret and cat primary visual cortex (v1) has been shown to be stable, in that the earliest measurable maps are similar in form to the eventual adult map, robust, in that similar maps develop in both dark rearing and in a variety of normal visual environments, and yet adaptive, in that the final map pattern reflects the statistics of the specific visual environment. how can these three properties be reconciled? using mechanistic models of the development of neu ... | 2013 | 24089483 |
| immune system cells in healthy ferrets: an immunohistochemical study. | the ferret has emerged as an excellent animal model to characterize several physiologic and pathologic conditions. the distribution and characterization of different types of immune system cells were studied in healthy ferret tissues. eight primary antibodies were tested for immunohistochemistry in formalin-fixed tissues: anti-cd3, anti-cd79α, anti-cd20, anti-hla-dr, anti-lysozyme, anti-cd163, anti-swc3, and anti-mac387. the anti-cd3 antibody labeled t cells mainly in interfollicular and paracor ... | 2014 | 24045889 |
| multiple effects of β-amyloid on single excitatory synaptic connections in the pfc. | prefrontal cortex (pfc) is recognized as an ad-vulnerable region responsible for defects in cognitive functioning. pyramidal cell (pc) connections are typically facilitating (f) or depressing (d) in pfc. excitatory post-synaptic potentials (epsps) were recorded using patch-clamp from single connections in pfc slices of rats and ferrets in the presence of β-amyloid (aβ). synaptic transmission was significantly enhanced or reduced depending on their intrinsic type (facilitating or depressing), aβ ... | 2013 | 24027495 |
| cutaneous neoplasia in ferrets, rabbits, and guinea pigs. | the frequency of common cutaneous tumors in ferrets, rabbits, and guinea pigs is summarized, with descriptions of their appearance and behavior, prognosis, and treatment options. this information assists clinicians when talking to clients, and helps owners make an informed decision whether or not to pursue aggressive treatment or to palliate. | 2013 | 24018027 |
| sparse coding models can exhibit decreasing sparseness while learning sparse codes for natural images. | the sparse coding hypothesis has enjoyed much success in predicting response properties of simple cells in primary visual cortex (v1) based solely on the statistics of natural scenes. in typical sparse coding models, model neuron activities and receptive fields are optimized to accurately represent input stimuli using the least amount of neural activity. as these networks develop to represent a given class of stimulus, the receptive fields are refined so that they capture the most important stim ... | 2013 | 24009489 |
| golgi cell activity during eyeblink conditioning in decerebrate ferrets. | golgi cells have a central position in the cerebellar cortical network and are indirectly connected to purkinje cells, which are important for the acquisition of learned responses in classical conditioning. in order to clarify the role of golgi cells in classical conditioning, we made extracellular golgi cell recordings during different stages of conditioning, using four different conditional stimuli. our results show that forelimb and superior colliculus stimulation, but not mossy fiber stimula ... | 2014 | 23982588 |
| fine-tuning of neurogenesis is essential for the evolutionary expansion of the cerebral cortex. | we used several animal models to study global and regional cortical surface expansion: the lissencephalic mouse, gyrencephalic normal ferrets, in which the parietal cortex expands more than the temporal cortex, and moderately lissencephalic ferrets, showing a similar degree of temporal and parietal expansion. we found that overall cortical surface expansion is achieved when specific events occur prior to surpragranular layer formation. (1) the subventricular zone (svz) shows substantial growth, ... | 2015 | 23968831 |
| postentry processing of recombinant adeno-associated virus type 1 and transduction of the ferret lung are altered by a factor in airway secretions. | we recently created a cystic fibrosis ferret model that acquires neonatal lung infection. to develop lung gene therapies for this model, we evaluated recombinant adeno-associated virus (raav)-mediated gene transfer to the neonatal ferret lung. unlike in vitro ferret airway epithelial (fae) cells, in vivo infection of the ferret lung with raav1 required proteasome inhibitors to achieve efficient airway transduction. we hypothesized that differences in transduction between these two systems were b ... | 2013 | 23948055 |
| number of spikes in climbing fibers determines the direction of cerebellar learning. | cerebellar learning requires context information from mossy fibers and a teaching signal through the climbing fibers from the inferior olive. although the inferior olive fires in bursts, virtually all studies have used a teaching signal consisting of a single pulse. following a number of failed attempts to induce cerebellar learning in decerebrate ferrets with a nonburst signal, we tested the effect of varying the number of pulses in the climbing fiber teaching signal. the results show that trai ... | 2013 | 23946401 |
| the medical implications of gastrointestinal vagal afferent pathways in nausea and vomiting. | nausea and vomiting are biological systems for defense against food poisoning that are also provoked by numerous drugs (e.g., chemotherapy, anesthesia) and chronic diseases (e.g., cancer, diabetic gastroparesis). the sensory pathways that stimulate nausea and vomiting include vestibular, area postrema, and forebrain inputs, but gastrointestinal vagal afferent fibers arguably play the most prominent role as a first-line defense. vagal sensory neurons detect toxins that enter the gastrointestinal ... | 2014 | 23886386 |
| effects of solar particle event proton radiation on parameters related to ferret emesis. | the effectiveness of simulated solar particle event (spe) proton radiation to induce retching and vomiting was evaluated in the ferret experimental animal model. the endpoints measured in the study included: (1) the fraction of animals that retched or vomited, (2) the number of retches or vomits observed, (3) the latency period before the first retch or vomit and (4) the duration between the first and last retching or vomiting events. the results demonstrated that γ ray and proton irradiation de ... | 2013 | 23883319 |
| implementing the cellular mechanisms of synaptic transmission in a neural mass model of the thalamo-cortical circuitry. | a novel direction to existing neural mass modeling technique is proposed where the commonly used "alpha function" for representing synaptic transmission is replaced by a kinetic framework of neurotransmitter and receptor dynamics. the aim is to underpin neuro-transmission dynamics associated with abnormal brain rhythms commonly observed in neurological and psychiatric disorders. an existing thalamocortical neural mass model is modified by using the kinetic framework for modeling synaptic transmi ... | 2013 | 23847522 |
| context-specific reweighting of auditory spatial cues following altered experience during development. | neural systems must weight and integrate different sensory cues in order to make decisions. however, environmental conditions often change over time, altering the reliability of different cues and therefore the optimal way for combining them. to explore how cue integration develops in dynamic environments, we examined the effects on auditory spatial processing of rearing ferrets with localization cues that were modified via a unilateral earplug, interspersed with brief periods of normal hearing. | 2013 | 23810532 |
| laminar firing and membrane dynamics in four visual areas exposed to two objects moving to occlusion. | it is not known how visual cortical neurons react to several moving objects and how their firing to the motion of one object is affected by neurons firing to another moving object. here we combine imaging of voltage sensitive dye (vsd) signals, reflecting the population membrane potential from ferret visual areas 17, 18, 19, and 21, with laminar recordings of multiunit activity, (mua), when two bars moved toward each other in the visual field, occluded one another, and continued on in opposite d ... | 2013 | 23805082 |
| laminar profile of visual response properties in ferret superior colliculus. | in the superior colliculus (sc), visual afferent inputs from various sources converge in a highly organized way such that all layers form topographically aligned representations of contralateral external space. despite this anatomical organization, it remains unclear how the layer-specific termination of different visual input pathways is reflected in the nature of visual response properties and their distribution across layers. to uncover the physiological correlates underlying the laminar orga ... | 2013 | 23803328 |
| bioelectric characterization of epithelia from neonatal cftr knockout ferrets. | cystic fibrosis (cf) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of cf transmembrane conductance regulator (cftr) chloride channel function found in many types of epithelia. animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in cf and developing therapies. cftr knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver d ... | 2013 | 23782101 |
| reduced subventricular zone proliferation and white matter damage in juvenile ferrets with kaolin-induced hydrocephalus. | hydrocephalus is a neurological condition characterized by altered cerebrospinal fluid (csf) flow with enlargement of ventricular cavities in the brain. a reliable model of hydrocephalus in gyrencephalic mammals is necessary to test preclinical hypotheses. our objective was to characterize the behavioral, structural, and histological changes in juvenile ferrets following induction of hydrocephalus. fourteen-day old ferrets were given an injection of kaolin (aluminum silicate) into the cisterna m ... | 2013 | 23769908 |
| imaging visual cortical structure and function in vivo. | the recent advent of in vivo two-photon microscopy has allowed the repeat imaging of cortical structures at microscopic resolution within intact brains. recent data obtained using this imaging technique shows that dendritic spines, the postsynaptic sites of the majority of excitatory synapses in the central nervous system (cns), rapidly remodel in response to changes in the visual environment. we combined two-photon microscopy of dendritic segments with intrinsic signal imaging of visual cortica ... | 2016 | 23733120 |
| development of a high density hemagglutinin protein microarray to determine the breadth of influenza antibody responses. | we have developed an influenza hemagglutinin protein microarray to assess humoral recognition of diverse influenza strains induced by vaccination and infection. each array consists of controls and 127 hemagglutinin antigens from 60 viruses, spotted in replicates to generate a single array of 1296 spots. six arrays are configured on a single slide, which in the following analysis was probed simultaneously with 2 isotype-specific fluorescent secondary antibodies yielding over 15,000 data points pe ... | 2013 | 23750544 |
| protection against lethal influenza with a viral mimic. | despite countermeasures against influenza virus that prevent (vaccines) and treat (antivirals) infection, this upper respiratory tract human pathogen remains a global health burden, causing both seasonal epidemics and occasional pandemics. more potent and safe new vaccine technologies would contribute significantly to the battle against influenza and other respiratory infections. using plasmid-based reverse genetics techniques, we have developed a single-cycle infectious influenza virus (sciiv) ... | 2013 | 23720727 |
| putting the tritone paradox into context: insights from neural population decoding and human psychophysics. | the context in which a stimulus occurs can influence its perception. we study contextual effects in audition using the tritone paradox, where a pair of complex (shepard) tones separated by half an octave can be perceived as ascending or descending. while ambiguous in isolation, they are heard with a clear upward or downward change in pitch, when preceded by spectrally matched biasing sequences. we presented these biased shepard pairs to awake ferrets and obtained neuronal responses from primary ... | 2013 | 23716220 |
| reducing uncertainty in within-host parameter estimates of influenza infection by measuring both infectious and total viral load. | for in vivo studies of influenza dynamics where within-host measurements are fit with a mathematical model, infectivity assays (e.g. 50% tissue culture infectious dose; tcid50) are often used to estimate the infectious virion concentration over time. less frequently, measurements of the total (infectious and non-infectious) viral particle concentration (obtained using real-time reverse transcription-polymerase chain reaction; rrt-pcr) have been used as an alternative to infectivity assays. we in ... | 2013 | 23691157 |
| mechanism of hypocoagulability in proton-irradiated ferrets. | to determine the mechanism of proton radiation- induced coagulopathy. | 2013 | 23651328 |
| selected emerging diseases in ferrets. | since their introduction as pets several decades ago, ferrets have become an increasingly popular household pet. great strides have been made in improving their diet and understanding common diseases (eg, insulinoma, hyperadrenocorticism, lymphoma) that affect them. with the frequency with which these conditions are seen, it sometimes is easy to forget that ferrets can be affected by other diseases. some of these diseases, such as cryptococcosis, are known, but may be increasing in incidence and ... | 2013 | 23642872 |
| the visual callosal connection: a connection like any other? | recent work about the role of visual callosal connections in ferrets and cats is reviewed, and morphological and functional homologies between the lateral intrinsic and callosal network in early visual areas are discussed. both networks selectively link distributed neuronal groups with similar response properties, and the actions exerted by callosal input reflect the functional topography of those networks. this supports the notion that callosal connections perpetuate the function of the lateral ... | 2013 | 23634306 |
| regulation of cerebral cortex size and folding by expansion of basal progenitors. | size and folding of the cerebral cortex increased massively during mammalian evolution leading to the current diversity of brain morphologies. various subtypes of neural stem and progenitor cells have been proposed to contribute differently in regulating thickness or folding of the cerebral cortex during development, but their specific roles have not been demonstrated. we report that the controlled expansion of unipotent basal progenitors in mouse embryos led to megalencephaly, with increased su ... | 2013 | 23624932 |
| behavioral sensitivity to broadband binaural localization cues in the ferret. | although the ferret has become an important model species for studying both fundamental and clinical aspects of spatial hearing, previous behavioral work has focused on studies of sound localization and spatial release from masking in the free field. this makes it difficult to tease apart the role played by different spatial cues. in humans and other species, interaural time differences (itds) and interaural level differences (ilds) play a critical role in sound localization in the azimuthal pla ... | 2013 | 23615803 |
| the readiness of snomed problem list concepts for meaningful use of electronic health records. | by 2015, snomed ct (sct) will become the usa's standard for encoding diagnoses and problem lists in electronic health records (ehrs). to facilitate this effort, the national library of medicine has published the "sct clinical observations recording and encoding" and the "veterans health administration and kaiser permanente" problem lists (collectively, the "pl"). the pl is studied in regard to its readiness to support meaningful use of ehrs. in particular, we wish to determine if inconsistencies ... | 2013 | 23602702 |
| using telemetry to automate the detection of emesis in the ferret: new vistas for delayed emesis assessment. | nausea and vomiting are common side effects of cancer chemotherapy. the ferret is a highly appropriate animal species to evaluate both early and delayed emetic events occurring hours and days after administration, respectively. if early emesis can be easily investigated in ferrets by direct observation, alternative methods are required to quantify delayed emesis. this study was designed to validate a new method of automated detection of abdominal pressure changes related to retches or vomits ind ... | 2013 | 23578691 |
| replication and immunogenicity of swine, equine, and avian h3 subtype influenza viruses in mice and ferrets. | since it is difficult to predict which influenza virus subtype will cause an influenza pandemic, it is important to prepare influenza virus vaccines against different subtypes and evaluate the safety and immunogenicity of candidate vaccines in preclinical and clinical studies prior to a pandemic. in addition to infecting humans, h3 influenza viruses commonly infect pigs, horses, and avian species. we selected 11 swine, equine, and avian h3 influenza viruses and evaluated their kinetics of replic ... | 2013 | 23576512 |
| cortical cholinergic input is required for normal auditory perception and experience-dependent plasticity in adult ferrets. | the nucleus basalis (nb) in the basal forebrain provides most of the cholinergic input to the neocortex and has been implicated in a variety of cognitive functions related to the processing of sensory stimuli. however, the role that cortical acetylcholine release plays in perception remains unclear. here we show that selective loss of cholinergic nb neurons that project to the cortex reduces the accuracy with which ferrets localize brief sounds and prevents them from adaptively reweighting audit ... | 2013 | 23575862 |
| altered migratory behavior of interneurons in a model of cortical dysplasia: the influence of elevated gabaa activity. | appropriate function of the neocortex depends on timely generation and migration of cells produced in the germinal zones of the neocortex and ganglionic eminence (ge). failure to accurately complete migration results in cortical dysplasia, a developmental syndrome implicated in many neurologic disorders. we developed a model of cortical dysplasia in ferrets involving administration of methylaxozymethanol acetate (mam), an antimitotic, to pregnant ferrets on gestational day 33, leading to dramati ... | 2014 | 23574639 |
| chemistry and pharmacological studies of 3-alkoxy-2,5-disubstituted-pyridinyl compounds as novel selective α4β2 nicotinic acetylcholine receptor ligands that reduce alcohol intake in rats. | neuronal acetylcholine receptors mediate the addictive effects of nicotine and may also be involved in alcohol addiction. varenicline, an approved smoking cessation medication, showed clear efficacy in reducing alcohol consumption in heavy-drinking smokers. more recently, sazetidine-a, which selectively desensitizes α4β2 nicotinic receptors, was shown to significantly reduce alcohol intake in a rat model. to develop novel therapeutics for treating alcohol use disorder, we designed and synthesize ... | 2013 | 23540678 |
| excellence in exotics: practice tip: ferret urinary tract catheterization. | in ferrets, urinary tract catheterization is most often indicated for neutered males with a urethral obstruction. obstructions are commonly caused by prostatic enlargement secondary to adrenal tumor hormone production or, less commonly, by urolithiasis. a ferret with a urethral obstruction needs immediate intervention to relieve the obstruction. | 2013 | 23532905 |
| auditory cortex represents both pitch judgments and the corresponding acoustic cues. | the neural processing of sensory stimuli involves a transformation of physical stimulus parameters into perceptual features, and elucidating where and how this transformation occurs is one of the ultimate aims of sensory neurophysiology. recent studies have shown that the firing of neurons in early sensory cortex can be modulated by multisensory interactions [1-5], motor behavior [1, 3, 6, 7], and reward feedback [1, 8, 9], but it remains unclear whether neural activity is more closely tied to p ... | 2013 | 23523247 |
| human liver bioengineering using a whole liver decellularized bioscaffold. | as a result of significant progress made in the last years in developing methods of whole organ decellularization techniques, organ bioengineering may now look more feasible than ever before. in this chapter, we describe in detail the necessary steps in human liver bioengineering. these include ferret liver decellularization by detergent perfusion, human liver progenitor and endothelial cell isolation, and finally, liver bioscaffold recellularization in a perfusion bioreactor. | 2013 | 23494438 |
| increased mechanical strain imposed on murine lungs during ventilation in vivo depresses airway responsiveness and activation of protein kinase akt. | continuous positive airway pressure (cpap) administered to tracheostomized rabbits and ferrets for 4 days or 2 wk suppresses bronchial reactivity in vivo and suppresses airway reactivity in lobes and tracheal segments isolated from these animals. in vitro studies of canine tracheal smooth muscle tissues indicate that mechanical loading suppresses the activation of the growth regulatory kinase, akt, and that akt is a negative regulator of smooth muscle differentiation. the transduction of mechani ... | 2013 | 23493362 |
| genetic variability of hev isolates: inconsistencies of current classification. | many hev and hev-like sequences have been reported during the last years, including isolates which may represent a number of potential new genera, new genotypes or new subtypes within the family hepeviridae. using the most common classification system, difficulties in the establishment of subtypes have been reported. moreover the relevance of subtype classification for epidemiology can be questioned. in this study we have performed phylogenetic analyses based on whole capsid gene and complete he ... | 2013 | 23434129 |
| a simple hplc method for the comprehensive analysis of cis/trans (z/e) geometrical isomers of carotenoids for nutritional studies. | geometrical isomers of carotenoids behave differently in aspects like stability towards oxidants, bioavailability, vitamin a activity and specificity for enzymes. the availability of hplc methods for their detailed profiling is therefore advisable to expand our knowledge on their metabolism and biological role. in this paper the development of a methodology to determine the highest number of geometrical isomers of major carotenoids in humans (phytoene, phytofluene, lutein, zeaxanthin, β-cryptoxa ... | 2013 | 23411252 |
| functional characterization of ferret ccl20 and ccr6 and identification of chemotactic inhibitors. | ccl20 is currently the only known chemokine ligand for the receptor ccr6, and is a mucosal chemokine involved in normal and pathological immune responses. although nucleotide sequence data are available for ccl20 and ccr6 sequences from multiple species, the ferret ccl20 and ccr6 sequences have not been determined. to increase our understanding of immune function in ferret models of infection and vaccination, we have used rt-pcr to obtain the ferret ccl20 and ccr6 cdna sequences and functionally ... | 2013 | 23360828 |
| viscoelastic properties of the ferret brain measured in vivo at multiple frequencies by magnetic resonance elastography. | characterization of the dynamic mechanical behavior of brain tissue is essential for understanding and simulating the mechanisms of traumatic brain injury (tbi). changes in mechanical properties may also reflect changes in the brain due to aging or disease. in this study, we used magnetic resonance elastography (mre) to measure the viscoelastic properties of ferret brain tissue in vivo. three-dimensional (3d) displacement fields were acquired during wave propagation in the brain induced by harmo ... | 2013 | 23352648 |
| spectral timbre perception in ferrets: discrimination of artificial vowels under different listening conditions. | spectral timbre is an acoustic feature that enables human listeners to determine the identity of a spoken vowel. despite its importance to sound perception, little is known about the neural representation of sound timbre and few psychophysical studies have investigated timbre discrimination in non-human species. in this study, ferrets were positively conditioned to discriminate artificial vowel sounds in a two-alternative-forced-choice paradigm. animals quickly learned to discriminate the vowel ... | 2013 | 23297909 |
| in vitro imaging of retinal whole mounts. | neuronal circuits of the vertebrate retina are organized into stereotyped laminae. this orderly arrangement makes the retina an ideal model system for imaging studies aimed at understanding how circuits assemble during development. in particular, live-cell imaging techniques are readily applied to the developing retina to monitor dynamic changes over time in cell structure and connectivity. such imaging studies have collectively revealed novel strategies by which retinal neurons contact their pr ... | 2013 | 23282639 |
| multisensory and unisensory neurons in ferret parietal cortex exhibit distinct functional properties. | despite the fact that unisensory and multisensory neurons are comingled in every neural structure in which they have been identified, no systematic comparison of their response features has been conducted. towards that goal, the present study was designed to examine and compare measures of response magnitude, latency, duration and spontaneous activity in unisensory and bimodal neurons from the ferret parietal cortex. using multichannel single-unit recording, bimodal neurons were observed to demo ... | 2013 | 23279600 |
| henipavirus infections: lessons from animal models. | the henipavirus genus contains two highly lethal viruses, the hendra and nipah viruses and one, recently discovered, apparently nonpathogenic member; cedar virus. these three, negative-sense single-stranded rna viruses, are hosted by fruit bats and use ephrinb2 receptors for entry into cells. the hendra and nipah viruses are zoonotic pathogens that emerged in the middle of 90s and have caused severe, and often fatal, neurologic and/or respiratory diseases in both humans and different animals; in ... | 2013 | 25437037 |
| pharmacological and nutritional agents promoting browning of white adipose tissue. | the role of brown adipose tissue in the regulation of energy balance and maintenance of body weight is well known in rodents. recently, interest in this tissue has re-emerged due to the realization of active brown-like adipose tissue in adult humans and inducible brown-like adipocytes in white adipose tissue depots in response to appropriate stimuli ("browning process"). brown-like adipocytes that appear in white fat depots have been called "brite" (from brown-in-white) or "beige" adipocytes and ... | 2013 | 23246573 |
| absence from work and the medical sickness certificate. | internet and dematerialization have greatly facilitated the medical profession. contractual physicians and national health service doctors now have efficient tools for the electronic management of their routine administrative workload. a recent innovation is the medical sickness certificate issued by primary care providers and national health service physicians. following postponements and uncertainties, procedures for the electronic completion and online transmission of the sickness certificate ... | 2013 | 23241839 |
| the laminar development of direction selectivity in ferret visual cortex. | sensory experience plays a critical role in the development of cortical circuits. at the time of eye opening, visual cortical neurons in the ferret exhibit orientation selectivity, but lack direction selectivity, which is a feature of mature cortical neurons in this species. direction selectivity emerges in the days and weeks following eye opening via a process that requires visual experience. however, the circuit mechanisms that underlie the development of direction selectivity remain unclear. ... | 2012 | 23238731 |
| anesthesia case of the month. hyperthermia and hypercarbia in a ferret during anesthesia. | | 2012 | 23216029 |
| deafferentation-induced plasticity of visual callosal connections: predicting critical periods and analyzing cortical abnormalities using diffusion tensor imaging. | callosal connections form elaborate patterns that bear close association with striate and extrastriate visual areas. although it is known that retinal input is required for normal callosal development, there is little information regarding the period during which the retina is critically needed and whether this period correlates with the same developmental stage across species. here we review the timing of this critical period, identified in rodents and ferrets by the effects that timed enucleat ... | 2012 | 23213572 |
| ferret lung transplant: an orthotopic model of obliterative bronchiolitis. | obliterative bronchiolitis (ob) is the primary cause of late morbidity and mortality following lung transplantation. current animal models do not reliably develop ob pathology. given the similarities between ferret and human lung biology, we hypothesized an orthotopic ferret lung allograft would develop ob. orthotopic left lower lobe transplants were successfully performed in 22 outbred domestic ferrets in the absence of immunosuppression (is; n = 5) and presence of varying is protocols (n = 17) ... | 2013 | 23205765 |
| comparison of the effects of antiarrhythmic drugs flecainide and verapamil on fkv1.4δn channel currents in xenopus oocytes. | to study the effects of na(+) channel blocker flecainide and l-type ca(2+) channel antagonist verapamil on the voltage-gated fkv1.4δn channel, an n-terminal-deleted mutant of the ferret kv1.4 k(+) channel. | 2013 | 23202797 |
| insulin glargine treatment of a ferret with diabetes mellitus. | a 7.5-year-old spayed female ferret was evaluated because of weight loss despite a good appetite. pancreatic insulinoma had been diagnosed at another animal hospital on the basis of detection of low blood glucose concentration on 1 occasion; however, concurrent determination of blood insulin concentration was not performed. the ferret had been treated sc with methylprednisolone acetate (unknown dosage) every 30 days for 2 years. no follow-up data regarding blood glucose concentration were availa ... | 2012 | 23176242 |
| laminar and connectional organization of a multisensory cortex. | the transformation of sensory signals as they pass through cortical circuits has been revealed almost exclusively through studies of the primary sensory cortices, for which principles of laminar organization, local connectivity, and parallel processing have been elucidated. in contrast, almost nothing is known about the circuitry or laminar features of multisensory processing in higher order, multisensory cortex. therefore, using the ferret higher order multisensory rostral posterior parietal (p ... | 2013 | 23172137 |
| reference intervals and working ferrets. | | 2012 | 23144096 |
| differential localization and function of antibody-forming cells responsive to inactivated or live-attenuated influenza virus vaccines. | currently, there are two different types of licensed influenza virus vaccines available in the usa, the live attenuated cold-adapted vaccine and the inactivated vaccine. children greater than 2 years of age and adults younger than 50 years (apart from those suffering from immunodeficiencies or lung disease) may choose between the two vaccines. previous studies have shown that both vaccines elicit significant serum antibody responses. however, comprehensive analyses of antibody-forming cells (afc ... | 2013 | 23143476 |
| the use of a slow release gnrh-agonist implant in female ferrets in season for oestrus suppression. | the jill is a long-day breeder with a constant oestrus without mating. persistent oestrogen production results in clinical signs of hyperoestrogenism including pancytopenia and death if untreated. as spaying is thought to be related to the development of hyperadrenocorticism, a non-invasive, safe and effective long-term treatment is needed for oestrus suppression in jills. seven jills in oestrus were treated with a 4.7mg deslorelin implant. blood samples for estradiol-17ß (e2) and progesterone ( ... | 2012 | 23117991 |
| expression of sfrp1 and activation of the wnt pathway in the adrenal glands of healthy ferrets and neutered ferrets with hyperadrenocorticism. | gonadectomy induces the pathogenesis of luteinising hormone receptor positive, androgen and oestrogen producing tumours in the adrenal cortex of ferrets. in mice, the castration-dependent appearance of adrenocortical tumours has been attributed to loss of expression of the tumour suppressor gene secreted frizzled related protein 1 (sfrp1), a dominant inhibitor of the wnt pathway, which controls cell proliferation and 'cell faith' decisions. this study investigated whether sfrp1 and the wnt pathw ... | 2013 | 23117029 |
| optimizing particle-mediated epidermal delivery of an influenza dna vaccine in ferrets. | particle-mediated dna delivery technologies ("gene guns") have been shown in both animal and clinical studies to be an effective means of increasing the immunogenicity and protective efficacy of dna vaccines. the primary goal in optimizing particle-mediated epidermal delivery (pmed) vaccination in different animal models is to achieve delivery of dna-coated gold beads into the viable epidermis. two key para-meters that influence this outcome include the delivery pressure, which controls the pene ... | 2013 | 23104347 |
| long-term synchronized electrophysiological and behavioral wireless monitoring of freely moving animals. | parallel electrophysiological recording and behavioral monitoring of freely moving animals is essential for a better understanding of the neural mechanisms underlying behavior. in this paper we describe a novel wireless recording technique, which is capable of synchronously recording in vivo multichannel electrophysiological (lfp, mua, eog, emg) and activity data (accelerometer, video) from freely moving cats. the method is based on the integration of commercially available components into a sim ... | 2013 | 23099345 |
| evidence for anti-inflammatory and putative analgesic effects of a monoclonal antibody to calcitonin gene-related peptide. | calcitonin gene-related peptide (cgrp) is a powerful pro-inflammatory mediator thought to play a significant role in the development of inflammation and pain. we investigated the role of cgrp in trigeminal inflammatory pain by determining the ability of a monoclonal antibody to cgrp to modify central fos expression in response to stimulation of the inflamed ferret tooth pulp. we also assessed the effect of the antibody on pulpal inflammation. | 2013 | 23098803 |
| scientific investigations into febrile reactions observed in the paediatric population following vaccination with a 2010 southern hemisphere trivalent influenza vaccine. | during the 2010 southern hemisphere (sh) influenza season, there was an unexpected increase in the number of febrile reactions reported in the paediatric population in australia shortly after vaccination with the csl 2010 trivalent influenza vaccine (tiv) compared to previous seasons. a series of scientific investigations were initiated to identify the root cause of these adverse events, including in vitro cytokine/chemokine assays following stimulation of adult and paediatric whole blood, as we ... | 2012 | 23063831 |
| zinc histochemistry reveals circuit refinement and distinguishes visual areas in the developing ferret cerebral cortex. | a critical question in brain development is whether different brain circuits mature concurrently or with different timescales. to characterize the anatomical and functional development of different visual cortical areas, one must be able to distinguish these areas. here, we show that zinc histochemistry, which reveals a subset of glutamatergic processes, can be used to reliably distinguish visual areas in juvenile and adult ferret cerebral cortex, and that the postnatal decline in levels of syna ... | 2013 | 23052548 |
| mapping pitch representation in neural ensembles with fmri. | functional magnetic resonance imaging (fmri) in humans and macaques allows a test of the hypothesis that there is a specialized neural ensemble for pitch within auditory cortex: a pitch center. fmri measures the blood oxygenation level-dependent (bold) response related to regional synaptic activity (logothetis et al., 2001). the distinction between synaptic activity and spike firing, and species differences encourage caution when comparing bold activity in humans and macaques to recordings from ... | 2012 | 23015424 |
| abnormal endocrine pancreas function at birth in cystic fibrosis ferrets. | diabetes is a common comorbidity in cystic fibrosis (cf) that worsens prognosis. the lack of an animal model for cf-related diabetes (cfrd) has made it difficult to dissect how the onset of pancreatic pathology influences the emergence of cfrd. we evaluated the structure and function of the neonatal cf endocrine pancreas using a new cftr-knockout ferret model. although cf kits are born with only mild exocrine pancreas disease, progressive exocrine and endocrine pancreatic loss during the first m ... | 2012 | 22996690 |
| a comparison of two methods of endoscopic dilation of acute subglottic stenosis using a ferret model. | balloon dilation is accepted as a first line treatment of acute subglottic stenosis, but its effects on the subglottic tissue remain largely unknown. we aimed to develop an animal model of acute subglottic stenosis using endoscopic techniques. once developed, this model was used to compare the immediate effects of balloon dilation and endotracheal tube dilation on subglottic tissue. | 2013 | 22961260 |
| radiographic kidney measurements in north american pet ferrets (mustela furo). | the purpose of the current study was to determine normal radiographic kidney -measurements in pet ferrets. | 2013 | 22957926 |
| impacts and outcomes of diabetes care in a high risk remote indigenous community over time: implications for practice. | the aim of this study was to determine diabetes care processes and intermediate clinical outcomes in a remote primary care service in 2009 compared with 2004. a retrospective review of diabetes care from january 2009 to january 2010 was conducted using a chronic disease register (project ferret). completeness of ascertainment was verified by a manual audit of charts. the results from this audit were compared with a similar study conducted in this community in 2004. the main outcome measure was d ... | 2013 | 22950855 |
| systemic coronavirus-associated disease resembling feline infectious peritonitis in ferrets in the uk. | | 2012 | 22923084 |
| comparison of the activation of somatostatin- and neuropeptide y-containing neuronal populations of the rat amygdala following two different anxiogenic stressors. | rats exposed to the odor of a predator or to the elevated plus maze express fear behaviors without a prior exposure to either stimulus. the expression of innate fear provides for an ideal model of anxiety which can aid in the elucidation of brain circuits involved in anxiety-related behaviors. the current experiments compared activation of neuropeptide-containing neuronal populations in the amygdala of rats exposed to either the elevated plus maze (epm; 5 min) versus home cage controls, or preda ... | 2012 | 22917777 |
| spectrotemporal contrast kernels for neurons in primary auditory cortex. | auditory neurons are often described in terms of their spectrotemporal receptive fields (strfs). these map the relationship between features of the sound spectrogram and firing rates of neurons. recently, we showed that neurons in the primary fields of the ferret auditory cortex are also subject to gain control: when sounds undergo smaller fluctuations in their level over time, the neurons become more sensitive to small-level changes (rabinowitz et al., 2011). just as strfs measure the spectrote ... | 2012 | 22895711 |
| early hearing-impairment results in crossmodal reorganization of ferret core auditory cortex. | numerous investigations of cortical crossmodal plasticity, most often in congenital or early-deaf subjects, have indicated that secondary auditory cortical areas reorganize to exhibit visual responsiveness while the core auditory regions are largely spared. however, a recent study of adult-deafened ferrets demonstrated that core auditory cortex was reorganized by the somatosensory modality. because adult animals have matured beyond their critical period of sensory development and plasticity, it ... | 2012 | 22888454 |
| reference ranges for laboratory parameters in ferrets. | the purpose of this study was to establish reference ranges (robust methods) for 51 laboratory parameters in ferrets for use in private practice. current literature concerning reference values in ferrets is often based on small patient numbers, methods of blood sampling not suitable for practice, and outdated laboratory methods. blood was collected from the v saphena lateralis of 111 clinically healthy ferrets (age 11 weeks to 9 years; 61 male, 50 female). age, sex (male or female) and fasting s ... | 2012 | 22859408 |
| the phase response of the cortical slow oscillation. | cortical slow oscillations occur in the mammalian brain during deep sleep and have been shown to contribute to memory consolidation, an effect that can be enhanced by electrical stimulation. as the precise underlying working mechanisms are not known it is desired to develop and analyze computational models of slow oscillations and to study the response to electrical stimuli. in this paper we employ the conductance based model of compte et al. (j neurophysiol 89:2707-2725, 2003) to study the effe ... | 2012 | 24995052 |
| compromise of auditory cortical tuning and topography after cross-modal invasion by visual inputs. | brain damage resulting in loss of sensory stimulation can induce reorganization of sensory maps in cerebral cortex. previous research on recovery from brain damage has focused primarily on adaptive plasticity within the affected modality. less attention has been paid to maladaptive plasticity that may arise as a result of ectopic innervation from other modalities. using ferrets in which neonatal midbrain damage results in diversion of retinal projections to the auditory thalamus, we investigated ... | 2012 | 22836267 |
| brain injury risk from primary blast. | military service members are often exposed to at least one explosive event, and many blast-exposed veterans present with symptoms of traumatic brain injury. however, there is little information on the intensity and duration of blast necessary to cause brain injury. | 2012 | 22836001 |
| ferrets further disease research. | | 2012 | 22821038 |
| effects of dronabinol on morphine-induced dopamine-related behavioral effects in animals. | the present study examined the effects of dronabinol, a united states fda-approved synthetic cannabinoid receptor agonist, on morphine (a prototypic μ-opioid receptor agonist)-induced dopamine-related behaviors in animals. dronabinol suppressed the rewarding effects of morphine in rats and its emetic effects in ferrets. furthermore, the morphine-induced increase in dopamine release from the nucleus accumbens was significantly attenuated by dronabinol, which indicated that the suppressive effects ... | 2012 | 22807156 |
| foxp2 is a parvocellular-specific transcription factor in the visual thalamus of monkeys and ferrets. | although the parallel visual pathways are a fundamental basis of visual processing, our knowledge of their molecular properties is still limited. here, we uncovered a parvocellular-specific molecule in the dorsal lateral geniculate nucleus (dlgn) of higher mammals. we found that foxp2 transcription factor was specifically expressed in x cells of the adult ferret dlgn. interestingly, foxp2 was also specifically expressed in parvocellular layers 3-6 of the dlgn of adult old world monkeys, providin ... | 2013 | 22791804 |
| [the role of the auditory cortex in the spatial information processing]. | sound localization is a computational process accomplished along the auditory pathway. once the acoustic information received at each ear is analyzed independently (monaural cues) and comparatively (binaural cues), those cues are integrated to generate a coherent spatial percept. using adult ferrets trained by positive conditioning in a spatial task, we aimed to study the role of the auditory cortex in the ability to localize sounds under both normal hearing and monaurally occluded conditions, t ... | 2012 | 22760769 |
| sparse coding on the spot: spontaneous retinal waves suffice for orientation selectivity. | ohshiro, hussain, and weliky (2011) recently showed that ferrets reared with exposure to flickering spot stimuli, in the absence of oriented visual experience, develop oriented receptive fields. they interpreted this as refutation of efficient coding models, which require oriented input in order to develop oriented receptive fields. here we show that these data are compatible with the efficient coding hypothesis if the influence of spontaneous retinal waves is considered. we demonstrate that ind ... | 2012 | 22734490 |
| rapid and efficient genetic manipulation of gyrencephalic carnivores using in utero electroporation. | higher mammals such as primates and carnivores have highly developed unique brain structures such as the ocular dominance columns in the visual cortex, and the gyrus and outer subventricular zone of the cerebral cortex. however, our molecular understanding of the formation, function and diseases of these structures is still limited, mainly because genetic manipulations that can be applied to higher mammals are still poorly available. | 2012 | 22716093 |
| signal detection in animal psychoacoustics: analysis and simulation of sensory and decision-related influences. | signal detection theory (sdt) provides a framework for interpreting psychophysical experiments, separating the putative internal sensory representation and the decision process. sdt was used to analyse ferret behavioural responses in a (yes-no) tone-in-noise detection task. instead of measuring the receiver-operating characteristic (roc), we tested sdt by comparing responses collected using two common psychophysical data collection methods. these (constant stimuli, limits) differ in the set of s ... | 2012 | 22698686 |
| a quantitative analysis of information about past and present stimuli encoded by spikes of a1 neurons. | to process the rich temporal structure of their acoustic environment, organisms have to integrate information over time into an appropriate neural response. previous studies have addressed the modulation of responses of auditory neurons to a current sound in dependence of the immediate stimulation history, but a quantitative analysis of this important computational process has been missing. in this study, we analyzed temporal integration of information in the spike output of 122 single neurons i ... | 2012 | 22696538 |
| contribution of pheromones processed by the main olfactory system to mate recognition in female mammals. | until recently it was widely believed that the ability of female mammals (with the likely exception of women) to identify and seek out a male breeding partner relied on the detection of non-volatile male pheromones by the female's vomeronasal organ (vno) and their subsequent processing by a neural circuit that includes the accessory olfactory bulb (aob), vomeronasal amygdala, and hypothalamus. emperical data are reviewed in this paper that demonstrate the detection of volatile pheromones by the ... | 2012 | 22679420 |
| five cases of contact dermatitis to a trendy pet. | skin contact with animal hair may induce contact urticaria (syndrome) or protein contact dermatitis. we report here 5 cases of dermatitis due to contact with ferrets kept as pets. the nature of the skin lesions, i.e. eczematous dermatitis, as well as the history of our 5 cases point to protein contact dermatitis. further studies are requested to confirm this hypothesis and to identify the mechanisms and allergens. physicians must be aware of the possibility of contact dermatitis with ferrets, es ... | 2012 | 22677934 |
| [heart abnormalities in the cat, dog and ferret]. | | 2012 | 22667184 |
| initial neighborhood biases and the quality of motion stimulation jointly influence the rapid emergence of direction preference in visual cortex. | visual experience plays a critical role in the development of direction-selective responses in ferret visual cortex. in visually naive animals, presentation of a bidirectional "training" stimulus induces rapid increases in the direction-selective responses of single neurons that can be predicted by small but significant direction biases that are present in neighboring neurons at the onset of stimulation. in this study we used in vivo two-photon imaging of calcium signals to further explore the c ... | 2012 | 22623671 |
| comparative processing and function of human and ferret cystic fibrosis transmembrane conductance regulator. | the most common cystic fibrosis transmembrane conductance regulator (cftr) gene mutation is δf508, and this causes cystic fibrosis (cf). new cf models in the pig and ferret have been generated that develop lung, pancreatic, liver, and intestinal pathologies that reflect disease in cf patients. species-specific biology in the processing of cftr has demonstrated that pig and mouse δf508-cftr proteins are more effectively processed to the apical membrane of airway epithelia than human δf508-cftr. t ... | 2012 | 22570484 |
| discovery of a novel orally active pde-4 inhibitor effective in an ovalbumin-induced asthma murine model. | phosphodiesterase-4 (pde-4) is responsible for metabolizing adenosine 3',5'-cyclic monophosphate that reduces the activation of a wide range of inflammatory cells including eosinophils. pde-4 inhibitors are under development for the treatment of respiratory diseases such as asthma and chronic obstructive pulmonary disease. herein, we report a novel pde-4 inhibitor, pde-423 (3-[1-(3-cyclopropylmethoxy-4-difluoromethoxybenzyl)-1h-pyrazol-3-yl]-benzoic acid), which shows good in vitro and in vivo o ... | 2012 | 22554769 |