| plasticity of spatial hearing: behavioural effects of cortical inactivation. | the cerebral cortex plays a critical role in perception and in learning-induced plasticity. we show that reversibly silencing any of the main regions of auditory cortex impairs the ability of adult ferrets to localize sound, with the largest deficit seen after deactivating the primary fields. although these animals had no trouble localizing longer sound bursts, their performance dropped considerably when auditory spatial cues were altered by occluding one ear with an earplug. in contrast to cont ... | 2012 | 22547635 |
| dynamics of phase-independent spectro-temporal tuning in primary auditory cortex of the awake ferret. | tuning of cortical neurons is often measured as a static property, or during a steady-state regime, despite a number of studies suggesting that tuning depends on when it is measured during a neuron's response (e.g., onset vs. sustained vs. offset). we have previously shown that phase-locked tuning to feature transients evolves as a dynamic quantity from the onset of the sound. in this follow-up study, we examined the phase-independent tuning during feature transients. based on previous results, ... | 2012 | 22531376 |
| multisensory dysfunction accompanies crossmodal plasticity following adult hearing impairment. | until now, cortical crossmodal plasticity has largely been regarded as the effect of early and complete sensory loss. recently, massive crossmodal cortical reorganization was demonstrated to result from profound hearing loss in adult ferrets (allman et al., 2009a). moderate adult hearing loss, on the other hand, induced not just crossmodal reorganization, but also merged new crossmodal inputs with residual auditory function to generate multisensory neurons. because multisensory convergence can l ... | 2012 | 22516008 |
| post-anesthesia vomiting: impact of isoflurane and morphine on ferrets and musk shrews. | although partially controlled with antiemetic drugs, postoperative nausea and vomiting (ponv) continues to be a problem for many patients. clinical research suggests that opioid analgesics and volatile anesthetics are the main triggers of ponv. the aim of this study was to develop an animal model for post-anesthesia vomiting for future studies to further determine mechanisms and preclinical drug efficacy. ferrets (n=34) were initially used because they have served as a gold standard for emesis r ... | 2012 | 22504494 |
| a review of pathophysiology and management of fetuses and neonates with meconium ileus for the pediatric surgeon. | meconium ileus (mi) is the earliest clinical manifestation of cystic fibrosis (cf), occurring in up to 20% of patients with cf. our aim was to review and integrate current knowledge about the diagnosis and management of fetuses and neonates with mi that may aid the pediatric surgeon in caring for these patients. | 2012 | 22498395 |
| dendritic spine density in multisensory versus primary sensory cortex. | in sensory areas, neuronal dendritic spines receive sensory-specific inputs whose net activity drives neuronal spiking responses to effective external stimuli. previous studies indicate that neurons in primary sensory cortical areas, which largely receive inputs from a single sensory modality, exhibit an average of 0.5-1.4 dendritic spines/μm, depending on species. in higher-order, associational cortices, inputs converge from multiple sensory sources onto individual, multisensory neurons. this r ... | 2012 | 22488884 |
| wired to run: exercise-induced endocannabinoid signaling in humans and cursorial mammals with implications for the 'runner's high'. | humans report a wide range of neurobiological rewards following moderate and intense aerobic activity, popularly referred to as the 'runner's high', which may function to encourage habitual aerobic exercise. endocannabinoids (ecbs) are endogenous neurotransmitters that appear to play a major role in generating these rewards by activating cannabinoid receptors in brain reward regions during and after exercise. other species also regularly engage in endurance exercise (cursorial mammals), and as h ... | 2012 | 22442371 |
| role of ca(2+) in the rapid cooling-induced ca(2+) release from sarcoplasmic reticulum in ferret cardiac muscles. | rapid lowering of the solution temperature (rapid cooling, rc) from 24 to 3°c within 3 s releases considerable amounts of ca(2+) from the sarcoplasmic reticulum (sr) in mammalian cardiac muscles. in this study, we investigated the intracellular mechanism of rc-induced ca(2+) release, especially the role of ca(2+), in ferret ventricular muscle. saponin-treated skinned trabeculae were placed in a glass capillary, and the amount of ca(2+) released from the sr by rc and caffeine (50 mm) was measured ... | 2012 | 22431072 |
| fabrication of an inexpensive, implantable cooling device for reversible brain deactivation in animals ranging from rodents to primates. | we have developed a compact and lightweight microfluidic cooling device to reversibly deactivate one or more areas of the neocortex to examine its functional macrocircuitry as well as behavioral and cortical plasticity. the device, which we term the "cooling chip," consists of thin silicone tubing (through which chilled ethanol is circulated) embedded in mechanically compliant polydimethylsiloxane (pdms). pdms is tailored to compact device dimensions (as small as 21 mm(3)) that precisely accommo ... | 2012 | 22402651 |
| spatial and temporal variations of cortical growth during gyrogenesis in the developing ferret brain. | spatial and temporal variations in cortical growth were studied in the neonatal ferret to illuminate the mechanisms of folding of the cerebral cortex. cortical surface representations were created from magnetic resonance images acquired between postnatal day 4 and 35. global measures of shape (e.g., surface area, normalized curvature, and sulcal depth) were calculated. in 2 ferrets, relative cortical growth was calculated between surfaces created from in vivo images acquired at p14, p21, and p28 ... | 2013 | 22368085 |
| dangerous for ferrets: lethal for humans? | | 2012 | 22348706 |
| contrast tuned responses in primary auditory cortex of the awake ferret. | auditory neurons are often characterized by their spectro-temporal receptive field (strf), a linear measure that captures overall trends of neural responses to modulations of the spectro-temporal envelopes of sounds. we have previously shown that primary auditory cortex neurons of the awake ferret are better characterized by strfs followed by a non-trivial non-linearity. this non-linearity is a half-wave rectification followed by a squaring function, indicating that cortical neurons probably enc ... | 2012 | 22321018 |
| task reward structure shapes rapid receptive field plasticity in auditory cortex. | as sensory stimuli and behavioral demands change, the attentive brain quickly identifies task-relevant stimuli and associates them with appropriate motor responses. the effects of attention on sensory processing vary across task paradigms, suggesting that the brain may use multiple strategies and mechanisms to highlight attended stimuli and link them to motor action. to better understand factors that contribute to these variable effects, we studied sensory representations in primary auditory cor ... | 2012 | 22308415 |
| functional biases in visual cortex neurons with identified projections to higher cortical targets. | visual perception involves information flow from lower- to higher-order cortical areas, which are known to process different kinds of information. how does this functional specialization arise? as a step toward addressing this question, we combined fluorescent retrograde tracing with in vivo two-photon calcium imaging to simultaneously compare the tuning properties of neighboring neurons in areas 17 and 18 of ferret visual cortex that have different higher cortical projection targets. | 2012 | 22305753 |
| avian influenza. the limits of avian flu studies in ferrets. | | 2012 | 22301288 |
| urine specific gravity values in clinically healthy young pet ferrets (mustela furo). | to determine urine specific gravity values in clinically healthy pet ferrets and explore possible associations with sex, sampling techniques, hydration status and urine analytes. | 2012 | 22283794 |
| the cult of personality testing: why assessments are essential for employee selection. | in today's complex business environment, it is more essential than ever to recognize that talent selection is critical and therefore must be at the top of a manager's list of priorities. it is very difficult to ferret out the important behavioral, motivational, and judgment traits that distinguish an inferior choice from a superior performer. adding people with high performance capability and low turnover potential adds tremendously to the bottom line. employing modern psychometric tools that ac ... | 2012 | 22283069 |
| functional properties of tooth pulp neurons responding to thermal stimulation. | the response properties of tooth pulp neurons that respond to noxious thermal stimulation of the dental pulp have been not well-studied. the present study was designed to characterize the response properties of tooth pulp neurons to noxious thermal stimulation of the dental pulp. experiments were conducted on 25 male ferrets, and heat stimulation was applied by a computer-controlled thermode. only 15% of tooth pulp neurons (n = 39) responded to noxious thermal stimulation of the teeth. tooth pul ... | 2012 | 22257665 |
| mycobacterial lesions in fish, amphibians, reptiles, rodents, lagomorphs, and ferrets with reference to animal models. | mycobacteriosis is a serious disease across many animal species. approximately more than 120 species are currently recognized in the genus mycobacterium. this article describes the zoonotic potential of mycobacteria and mycobacteriosis in fish, amphibians, rodents, rabbits, and ferrets. it considers clinical signs; histology; molecular methods of identification, such as polymerase chain reaction and dna sequencing; routes of infection; and disease progression. studying the disease in animals may ... | 2012 | 22244111 |
| canine distemper outbreak in ferrets in the uk. | | 2012 | 22228869 |
| the effects of proton radiation on the prothrombin and partial thromboplastin times of irradiated ferrets. | to determine whether proton radiation affects coagulation. | 2012 | 22221163 |
| nebulized live-attenuated influenza vaccine provides protection in ferrets at a reduced dose. | live-attenuated influenza vaccine (laiv) is delivered to vaccine recipients using a nasal spray syringe. laiv delivered by this method is immunogenic at current doses; however, improvements in nasal delivery might allow for significant dose reduction. we investigated laiv vaccination in ferrets using a high efficiency nebulizer designed for nasal delivery. laiv nasal aerosol elicited high levels of serum neutralizing antibodies and protected ferrets from homologous virus challenge at conventiona ... | 2012 | 22075083 |
| the effect of a monoclonal antibody to calcitonin-gene related peptide (cgrp) on injury-induced ectopic discharge following lingual nerve injury. | the development of ectopic neural discharge at a site of peripheral nerve injury is thought to contribute to the initiation of sensory disturbances and pain. we have previously shown that this discharge can be initiated or increased by the neuropeptide calcitonin gene-related peptide (cgrp). we have now studied a potential therapeutic approach to reducing the discharge by evaluating the effect of a systemically administered monoclonal antibody to cgrp on injury-induced activity in the lingual ne ... | 2011 | 22005578 |
| a novel computerized system for thermal stimulation of tooth in ferrets. | a dual thermal and electrical stimulator was developed to examine the central pathways that transmit noxious stimuli for intact dentition. this system allows computer-controlled stimulation of the canines of ferrets with either noxious heat or electrical stimuli. a set of in vitro studies demonstrated that the application of thermal stimuli to an intact tooth can produce pulpal temperatures above 43 °c, which is perceived as a painful stimulus in humans. in a set of in vivo studies, it was demon ... | 2012 | 22001221 |
| zoonoses of ferrets, hedgehogs, and sugar gliders. | with urbanization, people live in close proximity to their pets. people often share their living quarters and furniture, and this proximity carries a new potential for pathogen transmission. in addition to the change in lifestyle with our pets, new exotic pets are being introduced to the pet industry regularly. often, we are unfamiliar with specific clinical signs of diseases in these new exotic pets or the routes of transmission of pathogens for the particular species. this article reviews zoon ... | 2011 | 21872787 |
| emergence of tuning to natural stimulus statistics along the central auditory pathway. | we have previously shown that neurons in primary auditory cortex (a1) of anaesthetized (ketamine/medetomidine) ferrets respond more strongly and reliably to dynamic stimuli whose statistics follow "natural" 1/f dynamics than to stimuli exhibiting pitch and amplitude modulations that are faster (1/f(0.5)) or slower (1/f(2)) than 1/f. to investigate where along the central auditory pathway this 1/f-modulation tuning arises, we have now characterized responses of neurons in the central nucleus of t ... | 2011 | 21850231 |
| determination of axonal and dendritic orientation distributions within the developing cerebral cortex by diffusion tensor imaging. | as neurons of the developing brain form functional circuits, they undergo morphological differentiation. in immature cerebral cortex, radially-oriented cellular processes of undifferentiated neurons impede water diffusion parallel, but not perpendicular, to the pial surface, as measured via diffusion-weighted magnetic resonance imaging, and give rise to water diffusion anisotropy. as the cerebral cortex matures, the loss of water diffusion anisotropy accompanies cellular morphological differenti ... | 2012 | 21768045 |
| development of cortical orientation selectivity in the absence of visual experience with contour. | visual cortical neurons are selective for the orientation of lines, and the full development of this selectivity requires natural visual experience after eye opening. here we examined whether this selectivity develops without seeing lines and contours. juvenile ferrets were reared in a dark room and visually trained by being shown a movie of flickering, sparse spots. we found that despite the lack of contour visual experience, the cortical neurons of these ferrets developed strong orientation se ... | 2011 | 21753023 |
| high frequency stimulation abolishes thalamic network oscillations: an electrophysiological and computational analysis. | deep brain stimulation (dbs) of the thalamus has been demonstrated to be effective for the treatment of epilepsy. to investigate the mechanism of action of thalamic dbs, we examined the effects of high frequency stimulation (hfs) on spindle oscillations in thalamic brain slices from ferrets. we recorded intracellular and extracellular electrophysiological activity in the nucleus reticularis thalami (nrt) and in thalamocortical relay (tc) neurons in the lateral geniculate nucleus, stimulated the ... | 2011 | 21623007 |
| increasing numbers of giardia (but not coccidian) infections in ferrets, 2002 to 2010. | | 2011 | 21571856 |
| working ferrets: forgotten and neglected? | | 2011 | 21571853 |
| binaural sensitivity changes between cortical on and off responses. | neurons exhibiting on and off responses with different frequency tuning have previously been described in the primary auditory cortex (a1) of anesthetized and awake animals, but it is unknown whether other tuning properties, including sensitivity to binaural localization cues, also differ between on and off responses. we measured the sensitivity of a1 neurons in anesthetized ferrets to 1) interaural level differences (ilds), using unmodulated broadband noise with varying ilds and average binaura ... | 2011 | 21562191 |
| restoration of fractured canines in ferrets after one-step root canal treatment. | this article describes a one-step root canal treatment and restoration of canine teeth in ferrets. standard brass posts were used for the reconstruction of the teeth. the procedures were performed by dentists according to all rules and procedures used in root canal treatment in humans. the teeth were immediately restored anatomically. the procedures were successfully performed in four ferrets aged between 6 and 20 months of age, in three upper and one lower canines. | 2011 | 21528724 |
| β-cryptoxanthin supplementation prevents cigarette smoke-induced lung inflammation, oxidative damage, and squamous metaplasia in ferrets. | in epidemiologic studies, high intake of β-cryptoxanthin has been associated with a decreased risk of lung cancer, particularly among current smokers. however, data are not available from well-controlled animal studies to examine the effects of β-cryptoxanthin on cigarette smoke-induced lung lesions, and the biological mechanisms by which β-cryptoxanthin might affect lung carcinogenesis. we evaluated the effects of β-cryptoxanthin supplementation on cigarette smoke-induced squamous metaplasia, i ... | 2011 | 21421799 |
| learning stimulus intervals--adaptive timing of conditioned purkinje cell responses. | classical conditioning of motor responses, such as the eyeblink response, is an experimental model of associative learning and of adaptive timing of movements. a conditioned blink will have its maximum amplitude near the expected onset of the unconditioned blink-eliciting stimulus and it adapts to changes in the interval between the conditioned and unconditioned stimuli. previous studies have shown that an eyeblink conditioning protocol can make cerebellar purkinje cells learn to pause in respon ... | 2011 | 21416378 |
| application of a dense gas technique for sterilizing soft biomaterials. | sterilization of soft biomaterials such as hydrogels is challenging because existing methods such as gamma irradiation, steam sterilization, or ethylene oxide sterilization, while effective at achieving high sterility assurance levels (sal), may compromise their physicochemical properties and biocompatibility. new methods that effectively sterilize soft biomaterials without compromising their properties are therefore required. in this report, a dense-carbon dioxide (co(2) )-based technique was u ... | 2011 | 21337339 |
| competition and convergence between auditory and cross-modal visual inputs to primary auditory cortical areas. | sensory neocortex is capable of considerable plasticity after sensory deprivation or damage to input pathways, especially early in development. although plasticity can often be restorative, sometimes novel, ectopic inputs invade the affected cortical area. invading inputs from other sensory modalities may compromise the original function or even take over, imposing a new function and preventing recovery. using ferrets whose retinal axons were rerouted into auditory thalamus at birth, we were abl ... | 2011 | 21273321 |
| spontaneous cortical activity reveals hallmarks of an optimal internal model of the environment. | the brain maintains internal models of its environment to interpret sensory inputs and to prepare actions. although behavioral studies have demonstrated that these internal models are optimally adapted to the statistics of the environment, the neural underpinning of this adaptation is unknown. using a bayesian model of sensory cortical processing, we related stimulus-evoked and spontaneous neural activities to inferences and prior expectations in an internal model and predicted that they should ... | 2011 | 21212356 |
| wired on steroids: sexual differentiation of the brain and its role in the expression of sexual partner preferences. | the preference to seek out a sexual partner of the opposite sex is robust and ensures reproduction and survival of the species. development of female-directed partner preference in the male is dependent on exposure of the developing brain to gonadal steroids synthesized during critical periods of sexual differentiation of the central nervous system. in the absence of androgen exposure, a male-directed partner preference develops. the development and expression of sexual partner preference has be ... | 2011 | 22654808 |
| echocardiographic and electrocardiographic examination of clinically healthy, conscious ferrets. | to assess the feasibility of performing electrocardiography (ecg) and echocardiography on conscious ferrets and to establish reference values for this species under these conditions. | 2011 | 21143233 |
| disseminated idiopathic myofasciitis in ferrets. | first described in 2003, disseminated idiopathic myofasciitis (dim) has emerged as a new disease in young, domestic ferrets. dim is a severe inflammatory condition that affects primarily muscles and surrounding connective tissues. the disease is characterized by rapid onset of clinical signs, high fever, neutrophilic leukocytosis, and general lack of response to therapeutic intervention. until recently dim was considered fatal, but a few surviving ferrets indicate there may be an effective treat ... | 2010 | 20682436 |
| activation of nmda receptors is necessary for the recovery of cortical binocularity. | classic experiments have indicated that monocular deprivation (md) for a few days during a critical period of development results in a decrease in the strength of connections mediating responses to the deprived eye, leading to a dramatic breakdown of cortical neuron binocularity. despite the substantial functional change in the visual cortex, recovery from the effects of md can be obtained if binocular vision is promptly restored. while great efforts have been made to elucidate the mechanisms re ... | 2010 | 20457852 |
| reproductive features and faecal progesterone metabolite profile in female ferrets. | elevated post-partum progesterone metabolite (p(4) -met) levels have been recently postulated to occur in lactating lynxes. the aims of this study were to monitor reproductive features in female ferrets, changes in the faecal p(4) -met concentrations throughout the breeding season and ovarian activity in post-partum lactating and non-lactating (nl) female ferrets. our results indicate that coinciding with the results described in the lynx, elevated faecal p4-met concentrations occur in lactating ... | 2011 | 20456667 |
| ovariohysterectomy in ferrets. | surgical sterilization of ferrets is a relatively common surgical procedure. it is usually done as a method of contraception and to prevent diseases associated with the reproductive system. this column will describe the anatomy, principles, possible complications and outcomes of surgical ovariohysterectomy in ferrets. | 2010 | 20410897 |
| neural ensemble codes for stimulus periodicity in auditory cortex. | we measured the responses of neurons in auditory cortex of male and female ferrets to artificial vowels of varying fundamental frequency (f(0)), or periodicity, and compared these with the performance of animals trained to discriminate the periodicity of these sounds. sensitivity to f(0) was found in all five auditory cortical fields examined, with most of those neurons exhibiting either low-pass or high-pass response functions. only rarely was the stimulus dependence of individual neuron discha ... | 2010 | 20371828 |
| chronic detachable headphones for acoustic stimulation in freely moving animals. | a growing number of studies of auditory processing are being carried out in awake, behaving animals, creating a need for precisely controlled sound delivery without restricting head movements. we have designed a system for closed-field stimulus presentation in freely moving ferrets, which comprises lightweight, adjustable headphones that can be consistently positioned over the ears via a small, skull-mounted implant. the invasiveness of the implant was minimized by simplifying its construction a ... | 2010 | 20346981 |
| do ferrets perceive relative pitch? | the existence of relative pitch perception in animals is difficult to demonstrate, since unlike humans, animals often attend to absolute rather than relative properties of sound elements. however, the results of the present study show that ferrets can be trained using relative pitch to discriminate two-tone sequences (rising vs. falling). three ferrets were trained using a positive-reinforcement paradigm in which sequences of reference (one to five repeats) and target stimuli were presented, and ... | 2010 | 20329865 |
| [new drugs for small animals in 2009]. | in 2009, five active pharmaceutical ingredients were released on the german market for small animals. those are the analgesic buprenorphin (buprenovet®), the cytostatic masitinib (masivet®), the antiepileptic phenobarbital (phenoleptil®) and the cyclooxygenase-2-inhibitors mavacoxib (trocoxil®) and robenacoxib (onsior®). six additional substances were authorized for additional species. benazepril, cefalexin, ivermectin und ramipril are now available for cats, emodepsid in combination with praziq ... | 2010 | 22215315 |
| the descending corticocollicular pathway mediates learning-induced auditory plasticity. | descending projections from sensory areas of the cerebral cortex are among the largest pathways in the brain, suggesting that they are important for subcortical processing. although corticofugal inputs have been shown to modulate neuronal responses in the thalamus and midbrain, the behavioral importance of these changes remains unknown. in the auditory system, one of the major descending pathways is from cortical layer v pyramidal cells to the inferior colliculus in the midbrain. we examined the ... | 2010 | 20037578 |
| effect of conditioned stimulus parameters on timing of conditioned purkinje cell responses. | pavlovian eyeblink conditioning is a useful experimental model for studying adaptive timing, an important aspect of skilled movements. the conditioned response (cr) is precisely timed to occur just before the onset of the expected unconditioned stimulus (us). the timing can be changed immediately, however, by varying parameters of the conditioned stimulus (cs). it has previously been shown that increasing the intensity of a peripheral cs or the frequency of a cs consisting of a train of stimuli ... | 2010 | 20032243 |
| lesions of the auditory cortex impair azimuthal sound localization and its recalibration in ferrets. | the role of auditory cortex in sound localization and its recalibration by experience was explored by measuring the accuracy with which ferrets turned toward and approached the source of broadband sounds in the horizontal plane. in one group, large bilateral lesions were made of the middle ectosylvian gyrus, where the primary auditory cortical fields are located, and part of the anterior and/or posterior ectosylvian gyrus, which contain higher-level fields. in the second group, the lesions were ... | 2010 | 20032231 |
| cortical membrane potential dynamics and laminar firing during object motion. | when an object is introduced moving in the visual field of view, the object maps with different delays in each of the six cortical layers in many visual areas by mechanisms that are poorly understood. we combined voltage sensitive dye (vsd) recordings with laminar recordings of action potentials in visual areas 17, 18, 19 and 21 in ferrets exposed to stationary and moving bars. at the area 17/18 border a moving bar first elicited an on response in layer 4 and then on responses in supragranular a ... | 2009 | 19753323 |
| sensory and motor innervation of the crural diaphragm by the vagus nerves. | during gastroesophageal reflux, transient lower esophageal sphincter relaxation and crural diaphragm (cd) inhibition occur concomitantly. modifying vagus nerve control of transient lower esophageal sphincter relaxation is a major focus of development of therapeutics for gastroesophageal reflux disease, but neural mechanisms that coordinate the cd are poorly understood. | 2010 | 19732773 |
| scout's story: a case report on treating congestive heart failure in a ferret. | this case study reports on a ferret diagnosted with congestive heart failure. the veterinarians treated it with a compounded enalapril syrup successfully. radiographs of the thorax of the ferret are shown along with a photo of the ferret receiving her daily oral medication via oral syringe. | 2016 | 23966533 |
| congestive heart failure and other medical facts about ferrets. | congestive heart failure, the most common form of heart disease in aged ferrets, is only one of the diseases to which ferrets are susceptible. congestive heart failure is an insidious, progressive disease for which there is no cure. once the diagnosis is made and the proper medication is determined, the ferret must remain on the medication. the case report included with this article, which was submitted by a pet owner, and the accompanying formula is an example of how a compounding pharmacist ca ... | 2013 | 23966532 |
| little thief: the domestic ferret. | three illnesses appear commonly in pet ferrets: cardiomyopathies insulinoma, and adrenal associated endocrinopathy. treatment for dilated cardiomyopathy include ace inhibitors, and furosemide is recommended for the treatment for long-term diuresis treatment of congestive heart failure. insulinoma, cancer of the pancreas, is the most common neoplasm of the american ferret, often times treated by surgically excising the cancerous lobes, optionally can be treated with steroids that suppress insulin ... | 2016 | 23966531 |
| sensory activity differentially modulates n-methyl-d-aspartate receptor subunits 2a and 2b in cortical layers. | activity-dependent modulation of n-methyl-d-aspartate (nmda) receptors containing selective nr2 subunits has been implicated in plastic processes in developing and adult sensory cortex. aiming to reveal differential sensitivity of nr2 subunits to sustained changes in sensory activity, we utilized four paradigms that blocked, reinstated, or initiated sensory visual activity. laminar prevalence of n-methyl-d-aspartate receptor subunit 2a- (nr2a)- and n-methyl-d-aspartate receptor subunit 2b- (nr2b ... | 2009 | 19596055 |
| re: in support of ferrets. | | 2009 | 19472524 |
| neoplasitic diseases in ferrets in japan: a questionnaire study for 2000 to 2005. | the objective of this study was to collect epidemiological data on neoplasms in pet ferrets in japan. a questionnaire to collect information was made available to japanese veterinary practitioners through the web site of the japanese society of exotic pet medicine. completed questionnaires were returned from 29 practices, and 945 neoplasms met the criteria for inclusion in the study. neoplasms were found in every organ system except the respiratory system; the endocrine (418; 44.2%), integumenta ... | 2009 | 19420840 |
| radiographic measurement of cardiac size in 64 ferrets. | as ferrets can suffer from a wide variety of cardiac disorders, indicators for detecting cardiac abnormalities on plain chest radiography are necessary. a total of 64 ferrets without heart disease underwent radiography in the right lateral (rl) and ventrodorsal positions (vd), and the lengths of the rl-sixth dorsal vertebra (6th dv), rl- and vd-long axis (la) and rl- and vd-short axis (sa), rl- and vd- vertebral heart size, vd-length of the eighth costa (lec) and vd-thoracic width at the eighth ... | 2009 | 19346707 |
| developmental changes in brainstem neurons regulating lower airway caliber. | premature infants are at risk for lower airway obstruction; however, maturation of reflex pathways regulating lower airway patency is inadequately studied. we hypothesized that postnatal maturation causes developmental change in brainstem efferent airway-related vagal preganglionic neurons (avpns) within the rostral nucleus ambiguus (rna) that project to the airways and in pulmonary afferent fibers that terminate in the nucleus tractus solitarius (nts). ferrets aged 7, 14, 21, and 42 d received ... | 2009 | 19190536 |
| temporal coherence in the perceptual organization and cortical representation of auditory scenes. | just as the visual system parses complex scenes into identifiable objects, the auditory system must organize sound elements scattered in frequency and time into coherent "streams." current neurocomputational theories of auditory streaming rely on tonotopic organization of the auditory system to explain the observation that sequential spectrally distant sound elements tend to form separate perceptual streams. here, we show that spectral components that are well separated in frequency are no longe ... | 2009 | 19186172 |
| stimulus-timing-dependent plasticity of cortical frequency representation. | adult cortical circuits possess considerable plasticity, which can be induced by modifying their inputs. one mechanism proposed to underlie changes in neuronal responses is spike-timing-dependent plasticity (stdp), an up- or downregulation of synaptic efficacy contingent upon the order and timing of presynaptic and postsynaptic activity. the repetitive and asynchronous pairing of a sensory stimulus with either another sensory stimulus or current injection can alter the response properties of vis ... | 2008 | 19074036 |
| rapid modifications in calretinin immunostaining in the deep layers of the superior colliculus after unilateral cochlear ablation. | calretinin (cr) is a calcium-binding protein that plays an important role in the homeostasis of intracellular calcium concentration in the auditory pathway. to test if hearing loss could lead indirectly to modifications in levels of this calcium-binding protein in neurons and neuropilar structures outside of the lemniscal auditory pathway, cr-immunostaining was evaluated in the superior colliculus (sc) in adult ferrets at 1, 20 and 90 days after unilateral cochlear ablation. the results demonstr ... | 2009 | 19017539 |
| virtual adult ears reveal the roles of acoustical factors and experience in auditory space map development. | auditory neurons in the superior colliculus (sc) respond preferentially to sounds from restricted directions to form a map of auditory space. the development of this representation is shaped by sensory experience, but little is known about the relative contribution of peripheral and central factors to the emergence of adult responses. by recording from the sc of anesthetized ferrets at different age points, we show that the map matures gradually after birth; the spatial receptive fields (srfs) b ... | 2008 | 18987192 |
| experience with moving visual stimuli drives the early development of cortical direction selectivity. | the onset of vision occurs when neural circuits in the visual cortex are immature, lacking both the full complement of connections and the response selectivity that defines functional maturity. direction-selective responses are particularly vulnerable to the effects of early visual deprivation, but it remains unclear how stimulus-driven neural activity guides the emergence of cortical direction selectivity. here we report observations from a motion training protocol that allowed us to monitor th ... | 2008 | 18946471 |
| simple and complex spike firing patterns in purkinje cells during classical conditioning. | classical blink conditioning is known to depend critically on the cerebellum and the relevant circuitry is gradually being unravelled. several lines of evidence support the theory that the conditioned stimulus is transmitted by mossy fibers to the cerebellar cortex whereas the unconditioned stimulus is transmitted by climbing fibers. this view has been dramatically confirmed by recent purkinje cell recordings during training with a classical conditioning paradigm. we have tracked the activity of ... | 2008 | 18931885 |
| new insights in the neural regulation of the lower oesophageal sphincter. | gastro-oesophageal reflux disease (gord) is caused by disordered control of the gastro-oesophageal reflux barrier, comprised internally of the lower oesophageal sphincter (los) and externally the crural diaphragm (cd). both relax briefly to allow bolus passage during oesophageal peristalsis. brief relaxation also occurs prior to gastro-oesophageal reflux, known as transient los relaxation (tlosr), normally allowing venting of gas. tlosrs also account for up to 90% of acid reflux episodes. the de ... | 2008 | 18924442 |
| segregated hemispheric pathways through the optic chiasm distinguish primates from rodents. | at the optic chiasm retinal fibers either cross the midline, or remain uncrossed. here we trace hemispheric pathways through the marmoset chiasm and show that fibers from the lateral optic nerve pass directly toward the ipsilateral optic tract without any significant change in fiber order and without approaching the midline, while those from medial regions of the nerve decussate directly. anterograde labeling from one eye shows that the two hemispheric pathways remain segregated through the prox ... | 2008 | 18854206 |
| cytomorphological and immunohistochemical features of lymphoma in ferrets. | twenty ferrets with histopathologically diagnosed lymphoma were classified cytomorphologically and immunohistochemically. according to site of origin, multicentric, gastrointestinal, mediastinal and cutaneous lymphomas accounted for 8 (40%), 9 (45%), 2 (10%) and 1 case (5%), respectively. according to the national cancer institute working formulation (nci-wf), low-, high- and intermediate-grade lymphomas accounted for 4 (20%), 4 (20%) and 12 cases (60%), respectively. the 4 low-grade lymphomas s ... | 2008 | 18840962 |
| comments on treatment of hyperadrenocorticism in ferrets. | | 2008 | 18764701 |
| laboratory findings, histopathology, and immunophenotype of lymphoma in domestic ferrets. | lymphoma is a common tumor in ferrets, but anatomic distribution, histomorphology, immunophenotype, laboratory abnormalities, and response to chemotherapy are incompletely defined. in this study, lymphoma was diagnosed by histopathology of tumor tissue in 29 ferrets ranging in age from 0.8 to 8.5 years, including 12 males and 17 females. tumors involved the viscera of the abdominal cavity (n = 11), thoracic cavity (n = 1), or abdominal and thoracic cavities (n = 7); the skin (n = 2); or the visc ... | 2008 | 18725471 |
| effect of sb-750364, a specific trpv1 receptor antagonist, on injury-induced ectopic discharge in the lingual nerve. | abnormal neural activity generated at a site of nerve injury is thought to contribute to the development of dysaesthesia. vanilloid receptor 1 (trpv1), a transducer of noxious stimuli, may be involved in the initiation of this abnormal activity and could provide a useful therapeutic target. we investigated the effect of a specific trpv1 antagonist (sb-750364) on injury-induced discharge in the lingual nerve. in 12 anaesthetised adult ferrets the left lingual nerve was sectioned and animals were ... | 2008 | 18634850 |
| non-linear population firing rates and voltage sensitive dye signals in visual areas 17 and 18 to short duration stimuli. | visual stimuli of short duration seem to persist longer after the stimulus offset than stimuli of longer duration. this visual persistence must have a physiological explanation. in ferrets exposed to stimuli of different durations we measured the relative changes in the membrane potentials with a voltage sensitive dye and the action potentials of populations of neurons in the upper layers of areas 17 and 18. for durations less than 100 ms, the timing and amplitude of the firing and membrane pote ... | 2008 | 18628825 |
| p2x(3) expression is not altered by lingual nerve injury. | we have investigated a possible role for the atp receptor subunit p2x(3), in the development of neuropathic pain following injury to a peripheral branch of the trigeminal nerve. in nine anaesthetised adult ferrets the left lingual nerve was sectioned and recovery permitted for 3 days, 3 weeks or 3 months (3 ferrets per group). a retrograde tracer, fluorogold, was applied to the nerve to allow identification of cell bodies in the trigeminal ganglion with axons in the injured nerve. indirect immun ... | 2008 | 18597934 |
| long-term outcome of domestic ferrets treated surgically for hyperadrenocorticism: 130 cases (1995-2004). | to determine the long-term survival rate and factors that affect survival time of domestic ferrets treated surgically for hyperadrenocorticism. | 2008 | 18447778 |
| toxicology of ferrets. | because of their curious nature and small size, ferrets are at risk for various toxicoses. at present, there is not a great deal of information on specific toxicants in ferrets. this article initially reviews general consideration in treating poisoning in ferrets, such as obtaining history and decontamination. it then discusses some specific agents that appear to be common causes of poisoning in ferrets based on the experience of the aspca animal poison control center. | 2008 | 18406389 |
| sound localization behavior in ferrets: comparison of acoustic orientation and approach-to-target responses. | auditory localization experiments typically either require subjects to judge the location of a sound source from a discrete set of response alternatives or involve measurements of the accuracy of orienting responses made toward the source location. to compare the results obtained by both methods, we trained ferrets by positive conditioning to stand on a platform at the center of a circular arena prior to stimulus presentation and then approach the source of a broadband noise burst delivered from ... | 2008 | 18281159 |
| chemical coding and central projections of gastric vagal afferent neurons. | vagal afferents that innervate gastric muscle or mucosa transmit distinct sensory information from their endings to the nucleus of the tractus solitarius (nts). while these afferent subtypes are functionally distinct, no neurochemical correlate has been described and it is unknown whether they terminate in different central locations. this study aimed to identify gastric vagal afferent subtypes in the nodose ganglion (ng) of ferrets, their terminal areas in nts and neurochemistry for isolectin-b ... | 2008 | 18266614 |
| pancreatic endocrinopathies in ferrets. | pancreatic endocrinopathies, especially insulinomas, are a common finding in ferrets. surgical resection remains the treatment of choice for insulinomas because it can provide longer disease-free intervals and survival times. because of the high rate of metastasis, owners should be advised that treatment is rarely curative and is aimed at controlling the clinical signs of hypoglycemia by stopping or slowing the progression of the insulinoma. although less common, diabetes mellitus can occur in f ... | 2008 | 18165140 |
| a novel interhemispheric interaction: modulation of neuronal cooperativity in the visual areas. | the cortical representation of the visual field is split along the vertical midline, with the left and the right hemi-fields projecting to separate hemispheres. connections between the visual areas of the two hemispheres are abundant near the representation of the visual midline. it was suggested that they re-establish the functional continuity of the visual field by controlling the dynamics of the responses in the two hemispheres. | 2007 | 18074012 |
| dorsal motor nucleus of the vagus: a site for evoking simultaneous changes in crural diaphragm activity, lower esophageal sphincter pressure, and fundus tone. | the sphincter mechanism at the esophagogastric junction includes smooth muscle of the lower esophagus and skeletal muscle of the crural diaphragm (cd). smooth muscle is known to be under the control of the dorsal motor nucleus of the vagus (dmv), while central nervous system (cns) control of the cd is unknown. the main purposes of our study were to determine the cns site that controls the cd and whether simultaneous changes in lower esophageal sphincter (les) pressure and cd activity occur when ... | 2008 | 17977921 |
| alteration of visual input results in a coordinated reorganization of multiple visual cortex maps. | in the adult visual cortex, multiple feature maps exist and have characteristic spatial relationships with one another. the relationships can be reproduced by "dimension-reduction" computational models, suggesting that the principles of continuity and coverage may underlie cortical map organization. however, the mechanisms responsible for establishing these relationships are unknown. we explored whether removing one feature map during development causes a coordinated reorganization of the remain ... | 2007 | 17881536 |
| allergic lung inflammation affects central noradrenergic control of cholinergic outflow to the airways in ferrets. | brain stem noradrenergic cell groups mediating autonomic responses to stress project to airway-related vagal preganglionic neurons (avpns). in ferrets, their activation produces withdrawal of cholinergic outflow to the airways via release of norepinephrine and activation of alpha(2a)-adrenergic receptors (alpha(2a)-ar) expressed by avpns. in these studies, we examined the effects of allergen exposure of the airway (ae) with ovalbumin on noradrenergic transmission regulating the activity of avpns ... | 2007 | 17872402 |
| cochlear ablation in adult ferrets results in changes in insulin-like growth factor-1 and synaptophysin immunostaining in the cochlear nucleus. | afferent activity modulates synaptic plasticity as well as the levels of activity-dependent molecules such as growth factors. disruption of this activity due to deafferentation has been shown to result in an altered trophic support and consequently in changes in neuronal excitability and synaptic transmission. in the present study, to test whether lack of cochlear integrity results in changes in insulin-growth factor-1 (igf-1) and synaptophysin immunostaining in the cochlear nucleus, the first r ... | 2007 | 17764853 |
| purinergic p2x receptor activation induces emetic responses in ferrets and suncus murinus (house musk shrews). | despite the rapid progress made in understanding the significant role played by signalling via extracellular atp in physiology and pathology, there has been no clear information generated on its involvement in the emetic response. | 2007 | 17700716 |
| adaptive changes in cortical receptive fields induced by attention to complex sounds. | receptive fields in primary auditory cortex (a1) can be rapidly and adaptively reshaped to enhance responses to salient frequency cues when using single tones as targets. to explore receptive field changes to more complex spectral patterns, we trained ferrets to detect variable, multitone targets in the context of background, rippled noise. recordings from a1 of behaving ferrets showed a consistent pattern of plasticity, at both the single-neuron level and the population level, with enhancement ... | 2007 | 17699691 |
| neuronal death in the lateral geniculate nucleus of young ferrets following a cortical lesion: time-course, age dependence and involvement of caspases. | in humans and many other mammalian species, the behavioural consequences of a cortical lesion tend to be milder when it occurs early in life, and there is evidence that an important factor contributing to the behavioural sparing in the young is the formation of new thalamo-cortical connections by thalamic neurons initially connected with the lesioned area. however, this plasticity may be hindered by the secondary death of many of these neurons owing to the elimination by the primary lesion of th ... | 2007 | 17678880 |
| usefulness of the dopamine system-stabilizer aripiprazole for reducing morphine-induced emesis. | in the management of pain, nausea and vomiting are some of the most distressing adverse effects induced by opioids. in the present study, we investigated the effect of the dopamine system-stabilizer aripiprazole on morphine-induced emesis. morphine induced retching and vomiting in a dose-dependent manner in ferrets. the emetic effect of morphine was significantly suppressed by pretreatment with either the dopamine receptor antagonist haloperidol or aripiprazole. these results suggest that the co ... | 2007 | 17678644 |
| outcomes of adoption of adult laboratory ferrets after gonadectomy during a veterinary student teaching exercise. | we surveyed 27 people who had adopted a total of 43 adult domestic ferrets after their use in a series of veterinary student surgery teaching laboratories to assess the success of those adoptions and to determine the rate of occurrence of common maladies of domestic ferrets after adult gonadectomy as compared with the usual practice of early-age gonadectomy. the adoptions took place 1-7 y prior to the survey. the response rate was 48% of adopters, covering 53% of the ferrets. overall the success ... | 2007 | 17645296 |
| role of auditory cortex in sound localization in the midsagittal plane. | although the auditory cortex is known to be essential for normal sound localization in the horizontal plane, its contribution to vertical localization has not so far been examined. in this study, we measured the acuity with which ferrets could discriminate between two speakers in the midsagittal plane before and after silencing activity bilaterally in the primary auditory cortex (a1). this was achieved either by subdural placement of elvax implants containing the gaba a receptor agonist muscimol ... | 2007 | 17596417 |
| acquisition, extinction, and reacquisition of a cerebellar cortical memory trace. | associative learning in the cerebellum underlies motor memories and probably also cognitive associations. pavlovian eyeblink conditioning, a widely used experimental model of such learning, depends on the cerebellum, but the memory locus within the cerebellum as well as the underlying mechanisms have remained controversial. to date, crucial information on how cerebellar purkinje cells change their activity during learning has been ambiguous and contradictory, and there is no information at all a ... | 2007 | 17344387 |
| ultrasonographic visualization of the adrenal glands of healthy ferrets and ferrets with hyperadrenocorticism. | a protocol was developed to compare the ultrasonographic characteristics of the adrenal glands of 21 healthy ferrets and 37 ferrets with hyperadrenocorticism. by using specific landmarks, the adrenal glands were imaged in 97% of the cases. the adrenal glands of ferrets with hyperadrenocorticism had a significantly increased thickness, with changes in shape, structure, and echogenicity compared to the adrenal glands of healthy ferrets. based on the findings of the study, adrenal glands may be cla ... | 2016 | 17339284 |
| does attention play a role in dynamic receptive field adaptation to changing acoustic salience in a1? | acoustic filter properties of a1 neurons can dynamically adapt to stimulus statistics, classical conditioning, instrumental learning and the changing auditory attentional focus. we have recently developed an experimental paradigm that allows us to view cortical receptive field plasticity on-line as the animal meets different behavioral challenges by attending to salient acoustic cues and changing its cortical filters to enhance performance. we propose that attention is the key trigger that initi ... | 2007 | 17329048 |
| synaptophysin and insulin-like growth factor-1 immunostaining in the central nucleus of the inferior colliculus in adult ferrets following unilateral cochlear removal: a densitometric analysis. | in the present study, unilateral cochlear ablations were performed in adult ferrets to evaluate possible time-dependent modifications of synaptophysin and insulin-like growth factor-1 (igf-1) in the central nucleus of the inferior colliculus (cnic). using densitometric analysis, synaptophysin and igf-1 immunostaining were assessed at 1 (pa1) and 90 (pa90) days after cochlear ablation. the results demonstrated that 1 day after the lesion there was an increase in the levels of synaptophysin immuno ... | 2007 | 17318882 |
| cytologic diagnosis of diseases of ferrets. | cytology is a useful, rapid, inexpensive diagnostic technique that is particularly suitable for ferrets because of their small size and readily accessible organs and tissues. this article begins with a brief discussion of general cytologic information. the remainder of the article concentrates on the cytologic features of common diseases that affect ferrets. | 2007 | 17198960 |
| effects of melatonin administration on the clinical course of adrenocortical disease in domestic ferrets. | to evaluate the effect of oral administration of melatonin on clinical signs, tumor size, and serum steroid hormone concentrations in ferrets with adrenocortical disease. | 2006 | 17144819 |
| physiological and anatomical evidence for multisensory interactions in auditory cortex. | recent studies, conducted almost exclusively in primates, have shown that several cortical areas usually associated with modality-specific sensory processing are subject to influences from other senses. here we demonstrate using single-unit recordings and estimates of mutual information that visual stimuli can influence the activity of units in the auditory cortex of anesthetized ferrets. in many cases, these units were also acoustically responsive and frequently transmitted more information in ... | 2007 | 17135481 |
| efficacy and safety of selamectin in the treatment of otodectes cynotis infestation in domestic ferrets. | | 2006 | 17127760 |
| simple fall-off pattern of correlated neural activity in the developing lateral geniculate nucleus. | activity-dependent models for cortical simple-cell receptive field development predict specific patterns of correlated neural activity within the visual pathway, such as a mexican hat-shaped pattern of correlated activity in the lateral geniculate nucleus (lgn). however, such activity patterns have yet to be experimentally demonstrated. we performed multielectrode recordings in the lgn of immature awake ferrets and found simple fall-off-shaped, rather than mexican hat-shaped, patterns of correla ... | 2006 | 17115045 |