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preliminary description of a new squirrel from minnesota (sciurus carolinensis hypophaeus sp. nov.). 188617734895
habits of gray squirrels. 189417839115
the gray squirrel as a twig-pruner. 190217783172
migration of gray squirrels. 193517783401
migration of gray squirrels. 193617843859
eating of bone by the pregnant and lactating gray squirrel. 194017758842
the spectral sensitivity of the pure-cone retina of the grey squirrel (sciurus carolinensis leucotis). 195514368552
bleaching experiments on eyes of living grey squirrels (sciurus carolinensis leucotis). 195514368551
metastasizing viral fibromas of gray squirrels: pathogenesis and mosquito transmission. 195513228413
hepatozoon griseisciuri n. sp.; a new species of hepatozoon from the grey squirrel (sciurus carolinensis gmelin, 1788), with studies on the life cycle. 195813526069
naturally acquired toxoplasmosis in the gray squirrel, sciurus griseus, and its bearing on the laboratory diagnosis of rabies. 195913621032
studies on parasites of the grey squirrel (sciurus carolinensis gmelin) from south eastern england. i. helminth parasites. 196113730697
visual thresholds and spectral sensitivities of the grey squirrel (sciurus carolinensis leucotis). 196214013641
occurrence of enterococci in animals in a wild environment.enterococci were obtained from the feces of 71% of 216 mammals, 86% of 70 reptiles, and 32% of 22 birds sampled in a truly wild environment, the great smoky mountains national park. patterns of food dependence and also of species dependence were observed. among the lower classes of the primarily herbivorous mammals, the enterococci occurred sporadically; however, of the six species of sciuridae, the gray squirrel, and of four species of cricetidae, the red-backed mouse, the enterococci appear to ...196313936610
some observations on the fine structure of the retinal receptors of the american gray squirrel. 196414166277
serum proteins of the grey squirrel (sciurus carolinensis). 19655847426
cutaneous mucormycosis (phycomycosis) in a squirrel (sciurus carolinensis). 19665950167
hematological values for the eastern gray squirrel (sciurus carolinensis). 19665905880
yellow lens pigment of the grey squirrel (sciurus carolinensis leucotis). 19676030527
the yellow colour of the lens of the grey squirrel (sciurus carolinensis leucotis).1. the absorption spectrum of the lens of the grey squirrel (sciurus carolinensis leucotis) has been measured, revealing an absorption maximum at 370 nm. peak densities in the intact lens ranged from 12 to 20.2. this peak is not present in the lenses of horse, cow, pig, dog, cat, ferret (mustelo furo), or guinea-pig (cavia porcellus).3. the pigment responsible for this absorption is water-soluble and aqueous extracts have been examined. protein-free aqueous extracts show an additional maximum at ...19695796470
notes on gongylonema pulchrum molin, 1857 (nematoda: spiruridae) in the gray squirrel in southwestern virginia. 19715090971
occurrence of neohaematopinus sciuri jancke, 1933 on a west virginia gray squirrel. 19715105974
uroporphyrinogen 3 cosynthetase activity in the fox squirrel (sciurus niger).the activity of uroporphyrinogen iii cosynthetase in hemolyzates and tissue extracts from fox squirrels is much less than in similar preparations from gray squirrels. low activity of this enzyme explains the production of large amounts of uroporphyrin i by the fox squirrel. members of this species thus provide a small-animal model for studies of congenital erythropoietic porphyria, a hereditary disease of man and cattle which is associated with a similar partial deficiency of uroporphyrinogen ii ...19715120867
transmission of proteins from mother to conceptus in the grey squirrel (sciurus carolinensis). 19714138023
observations on parasites of gray squirrels during the 1968 emigration in north carolina. 19715581376
representation of the visual field in the superior colliculus of the grey squirrel (sciurus carolinensis) and the tree shrew (tupaia glis). 19715547178
eimeria ontarioensis n. sp., e. confusa joseph, 1969 and eimeria sp. (protozoa: eimeriidae) from the ontario gray squirrel sciurus carolinensis. 19714943761
visual cortex of the grey squirrel (sciurus carolinensis): architectonic subdivisions and connections from the visual thalamus. 19725030907
role of haemogamasus reidi (acari: mesostigmata) in the life cycle of the gray squirrel protozoan, hepatozoon griseisciuri (sporozoa: haemogregarinidae). 19724623381
eimeria lancasterensis joseph, 1969 and e. confusa joseph, 1969 from the grey squirrel sciurus carolinensis. 19725008845
eimeria ontarioensis lee and dorney, 1971, from the gray squirrel, sciurus carolinensis, in massachusetts. 19734696581
erythropoietic porphyria of the fox squirrel sciurus niger.uroporphyrin i is found in high concentration in the bones, teeth, blood, soft tissues, and urine of the fox squirrel, sciurus niger. the concentration of uroporphyrin in fox squirrel spleen is much higher than in liver, kidney or bone marrow, probably because of accumulation from phagocytosed red cells. bleeding causes a marked increase in the uroporphyrin concentration of red cells and spleen, and a 3-8-fold increase in uroporphyrin excretion. urinary excretion of delta-aminolevulinic acid and ...19734682390
hymenolepis diminuta in a gray squirrel from indiana. 19744826120
ecology of keystone virus, a transovarially maintained arbovirus.our studies in the pocomoke cypress swamp of maryland have shown that key strain of ce is endemic and is carried by the floodwater mosquito a. atlanticus. the virus is transmitted transstadially in nature, as evidenced by our recovery of virus from larvae and males of this species. serologic evidence, both here and elsewhere, indicates that vertebrates are infected with key, but their role in the transmission cycle remains unknown. we have found several animals, for example, the gray squirrel, t ...197520017
electrophysiological evidence for rod-like receptors in the gray squirrel, ground squirrel and prairie dog retinas.spectral sensitivities of the gray squirrel, mexican and 13-line ground squirrel and prairie dog were determined by electroretinography under both dark- and light-adapted conditions. the dark-adapted spectral sensitivity function obtained from intact eyes of these species peaks between 515-525 nm; however, when corrected for lens absorption or recorded from the lensless eye, it peaks near 500 nm and closely matches in shape a rhodopsin nomogram curve (lambda max equals 502 nm). upon light adapta ...19751127140
leptospirosis in selected wild mammals of the florida panhandle and southwestern georgia.a group of 144 wild mammals, including white-tailed deer, cottontail rabbits, fox squirrels, gray squirrels, raccoons, opossums, a bobcat, and various small rodents was examined for cultural or serologic evidence of leptospiral infection. leptospires were isolated from 1 of 25 rabbits, 1 of 27 fox squirrels, 1 of 26 gray squirrels, 4 of 18 mice and rats, 8 of 21 raccoons, 7 of 17 opossums, and a bobcat. isolations were not made from 6 deer examined. serotypes isolated were leptospira interrogans ...19751176352
a microbiologic study of the urban gray squirrel.bacteriologic, virologic, and serologic examinations were conducted on 180 urban gray squirrels (sciurus carolinensis) during a 1-year period in a metropolitan area. evidence was not found of infections with leptospires, enteric or other bacteria, rickettsial agents, francisella tularensis, or arthropod-borne viruses. the squirrels were remarkably free of evidence of bacterial or viral infections of importance to man and lower animals.19751176356
public health and the urban gray squirrel: mycology.from 180 gray squirrels (sciurus c. carolinesis), 942 isolates of fungi representing 19 genera were recovered upon culture of hair-skin scrapings and toenails. of the isolates, 170 represented known human pathogens and 142, squirrel pathogens. a human infection of trichophyton mentagrophytes was derived from handling the squirrels. skin lesions of seven squirrels were attributable to t. mentagrophytes and mucor sp.19751195491
dirofilariaformia pulmoni sp. n. (nematoda: onchocercidae) from the eastern gray squirrel (sciurus carolinensis gmelin).dirofilariaeformia pulmoni sp. n. from the eastern gray squirrel (sciurus carolinensis gmelin) is differentiated from other species of the genus by its smaller body size, shorter spicules, arrangement of caudal papillae, and morphology of microfilariae. adult filarids were found in the pulmonary artery and its branches, and the microfilariae occurred in the blood. a large antemortem thrombus that occluded approximately two-thirds of the lumen of the artery was associated with infection in one sq ...19751127566
anatomical evidence for cone and rod-like receptors in the gray squirrel, ground squirrel, and prairie dog retinas.in the gray squirrel (sciurus carolinensis), the prairie dog (cynomys ludovicianus), and the mexican and 13-line ground squirrels (citellus mexicanus and c. tridecemlineatus) there exist two distinct classes of photo-receptors that have cone-like and rod-like anatomical features respectively. these two receptor classes were previously known to exist in the gray squirrel, but only the cone-like (c) receptor had been observed in the other species. we have now found small numbers of rod-like (r) re ...19751127139
proceedings: the visual pigments of the grey squirrel, sciurus carolinensis leucotis. 19751185642
a field water balance study of gray squirrels (sciurus carolinensis) and red squirrels (tamiasciurus hudsonicus). 1975237697
connections of layer vi in striate cortex of the grey squirrel (sciurus carolinensis). 197549213
experimental transmission of eimeria confusa joseph 1969 to the fox squirrel.eimeria confusa joseph, 1969 from the gray squirrel sciurus carolinensis was transmitted to the fox squirrel sciurus niger rufiventer. this is the first report of the successful cross-transmission of a gray squirrel coccidium to the fox squirrel.19751152180
life span and reproductive longevity of the gray squirrel, sciurus c. carolinensis gmelin. 19751141781
blood and urinary values in the gray squirrel.uric acid, blood urea nitrogen, glucose, total serum protein, cholesterol, triglyceride, calcium, magnesium, phosphorus, and chloride concentrations in the blood plus ph, bilirubin, ketone, blood, protein and glucose levels in the urine were determined for gray squirrels captured in jacksonville, florida. significant differences were not noted for any of these values when compared by the age or sex of the animals, by breeding or lactation status, by month of capture, or by habitat type. depresse ...197616498875
seasonal changes in the testis and epididymis of the american grey squirrel, sciurus carolinensis. 19761001802
a correction in the literature on cestodes from sciurus carolinensis. 19761255385
wavelength discrimination in gray squirrels. 19761266079
hematologic values for free-ranging urban gray squirrels (sciurus c carolinensis).gray squirrels (sciurus carolinensis carolinensis) (n=180) from jacksonville, fl, were examined for hematologic values: erythrocyte sedimentation rate, packed cell volume, hemoglobin (hb) concentration, erythrocyte and leukocyte counts, differential leukocyte counts, blood platelet counts, hb electrophoresis, and erythrocyte fragility. results were compared by age and by sex of the squirrels and by month of capture.19761247206
projections from the superior colliculus to the dorsal lateral geniculate nucleus of the grey squirrel (sciurus carolinensis) 1976953742
hepatozoon griseisciuri infection in gray squirrels of the southeastern united states.blood films and selected tissue sections from 270 gray squirrels (sciurus carolinensis) from 18 sites in 11 southeastern states were examined for hepatozoan griseisciuri. this parasite was found in 110 (41%) squirrels from 17 of the 18 sites. data suggested transmission of the parasite apparently occurs throughout the year and increases from spring to late summer. the infection was more prevalent in subadults and adults than in juveniles. schizogonic stages were found only in the lungs, suggesti ...1976815571
heavy metal concentrations in kidneys of urban gray squirrels.concentrations of lead and zinc in the kidneys of 180 urban gray squirrels were determined by spectrophotometry and found similar for all age groups; however, concentrations of cadmium increased up to two years of age. values for 12 rural squirrels were significantly lower than those of the urban animals. there were no differences in mean concentrations of the metals when urban squirrels were grouped by the land usage pattern of the sites in which they were captured. grouping squirrels by human ...197616498879
california arbovirus (la crosse) infections. iii. epidemiology of california encephalitis in minnesota.mosquitoes (eggs, larvae, and adults), small woodland animals, and residents of an area where california encephalitis is endemic were studied to elucidate the host-vector cycle of la crosse virus. elementary schoolchildren from surrounding communities and gray squirrels from another area were tested to compare the prevelence of serum antibodies to la crosse virus in areas where the disease is endemic with the prevalence of these antibodies in areas where the disease is not endemic. from 1971 to ...19763613
preliminary studies on the characterization and distribution of staphylococcus and micrococcus species on animal skin.a total of 221 strains of staphylococci and 98 strains of micrococci isolated from the skins of eastern gray squirrels, southern flying squirrels, raccoons, opossums, squirrel monkeys, swine, sheep, horses, cattle, and dogs were characterized in a preliminary attempt to resolve their natural relationships and distribution in nature. staphylococci demonstrating the widest host range included staphylococcus xylosus and unnamed staphylococcus sp. 3. unnamed staphylococcus sp. 2 was isolated only fr ...1976942208
electrophoretic separation of serum proteins from gray squirrels.serum proteins of gray squirrels were electrophoretically separated into 7 fractions as compared with the 5 fractions obtained from human serum. the mobility of the albumin fraction was approximately the same for both human and squirrel serums. the prealbumin fraction did not vary significantly in the percentage for squirrels bled at different times of the year. immunoelectrophoresis patterns showed squirrel serum had a small number of fractions with the same antigenic characteristics as human s ...1976984553
viremia and antibody response to la crosse virus in sentinel gray squirrels (sciuris carolinensis) and chipmunks tamias striatus).six isolates of la crosse (lac) virus were obtained from sentinel gray squirrels (sciuris carolinensis) and four from sentinel chipmunks (tamias striatus) in an endemic area. viremia titers were measured by plaquing on vero cells. antibody responses of the animals were measured by a microneutralization test employing four california group viruses: lac, snowshoe hare (ssh), trivittatus, and jamestown canyon. in both species lac antibody titers peaked at approximately 21 days and were still detect ...1977889022
coccidia of urban gray squirrels in northern florida. 1977592033
bergmann's rule and variation in structures related to feeding in the gray squirrel. 197728563478
dispersal of sweet pignut hickory in a year of low fruit production, and the influence of predation by a curculionid beetle.the rate at which fallen hickory nuts are removed from beneath the parent tree, and the effect on this rate of the seed predatorconotrachelus affinis, was studied in an oak-hickory forest in southeastern michigan, usa, during a year in which few nuts were produced. the trees responded toconotrachelus, which destroyed half the nut crop, by aborting inviable nuts during the summer. the seed dispersers, mostly gray squirrels, removed fallen nuts rapidly, showing the ability to distinguish viable nu ...197728309253
the organization of the pulvinar in the grey squirrel (sciurus carolinensis). ii. synaptic organization and comparisons with the dorsal lateral geniculate nucleus.the purpose of these experiments was to compare the synaptic organization of the subdivisions of the pulvinar defined in the preceding paper (robson and hall, '77) with each other and with the organization present in the dorsal lateral geniculate nucleus. the electron microscope was used to analyze normal synaptic arrangements and degenerating axonal terminals resulting from lesions. the dorsal lateral geniculate nucleus in the grey squirrel contains synaptic clusters similar to those described ...1977853144
ovarian follicular changes in gray squirrels as affected by season, age, and reproductive state. 1977850110
correlation between ultrastructure and biochemical changes in the testis of the american grey squirrel, sciurus carolinensis, during the reproductive cycle.distinct differences in tha ability of isolated seminiferous tubules and interstitium to utilize steroid precursors for androgen production in vitro were observed during the reproductive cycle of the american grey squirrel, sciurus carolinensis. in spermatogenically active testes, the seminiferous tubules and the interstitium readily synthesized androgens from labelled c21 steroid precursor; seminiferous tubules also produced significant amounts of 17alpha,20alpha-dihydroxyprogesterone. however, ...1977833787
the organization of the pulvinar in the grey squirrel (sciurus carolinensis). i. cytoarchitecture and connections.the posterior neocortex in the grey squirrel, sciurus carolinensis, includes an extensive region which receives projections from the pulvinar. previous studies have demonstrated that this cortical region can be subdivided on the basis of differences in cytoarchitecture and electrophysiologically defined representations of the visual field. the main purpose of the present paper was to determine whether these cortical subdivisions could be related to corresponding subdivisions in the pulvinar. the ...1977856889
bipolar and horizontal cells of the gray squirrel retina: golgi morphology and receptor connections. 1978664282
pesticide levels in the omental fat of urban gray squirrels. 1978630144
the prevalence of serum antibodies to toxoplasma gondii in ontario mammals.the prevalence of seropositive reactions to toxoplasma gondii was studied in farm animals, companion animals, wild rodents and birds. of the animals tested, 17% of cattle, 65% of sheep, 45% of pigs, 9% of horses, 33% of dogs and 20% of cats were seropositive by the sabin-feldman dye test. in addition 11% of mice (mus musculus), 5% of deer mice (peromyscus), 3% of rats (rattus norvegicus) and less than 2% of sparrows (passer domestcus) were seropositive. all samples from short-tailed field mice ( ...1978667705
rocky mountain spotted fever in connecticut: human cases, spotted-fever group rickettsiae in ticks, and antibodies in mammals.three parameters were used in 1976 and 1977 to assess the status of rocky mountain spotted fever (rmsf) in connecticut--compilation and review of clinical data on suspected human cases for the 13-year period 1965--1977, examination of tick tissues for spotted fever-group rickettsiae by the hemolymph test and direct immunofluorescence, and analyses of mammalian sera for antibodies against rickettsia rickettsii. there were six presumptive rmsf cases which probably originated in connecticut. four o ...1979111543
experimental infection of vertebrates of the pocomoke cypress swamp, maryland with keystone and jamestown canyon viruses.experimental studies were conducted to assess the susceptibility of white-tailed deer (odocoileus virginianus), gray squirrels (sciurus carolinensis), and cottontail rabbits (sylvilagus floridanus) to jamestown canyon (jc) and/or keystone (key) virus infection. viremia occurred in 5 of 6 deer inoculated with jc virus; however, all deer developed key virus neutralizing antibody. based on the observation that antibody elicited by primary infection of deer with either key or jc virus exhibited part ...1979453437
human enteroviruses and wildlife: isolation from gray squirrels.five isolates of human echovirus 1/8 complex were recovered from the feces of free-ranging gray squirrels. the source of infection and the significance of the isolates remain unknown.19807373721
mercury and cesium-137 in urban gray squirrels. 19807426779
congenital aortic stenosis in an eastern gray squirrel. 19807451349
poxvirus and multiple tumors in an eastern gray squirrel.a moribund juvenile gray squirrel (sciurus carolinensis) with numerous skin fibromas was submitted to the northeastern research center for wildlife diseases. necropsy revealed multiple firm white nodules in the lungs. on histologic examination, in addition to the skin lesions, fibromatous proliferations were seen in the wall of the alimentary tract, in 1 mesenteric lymph node, and in the myocardium. tubular adenomas were seen in the renal cortex, and the lung nodules were bronchoalveolar adenoma ...19806256332
metabolism of androgens by the active and inactive prostate gland, and the seasonal changes in systemic androgen levels in the grey squirrel (sciurus carolinensis gmelin).the nuclear and cytoplasmic fractions derived from the actively secretory and inactive prostate of adult grey squirrels were incubated with radioactive testosterone and androstenedione. testosterone was metabolized first to 5 alpha-dihydrotestosterone and then 5 alpha-androstane-3 alpha(beta), 17 beta-diols. testosterone could also be transformed into androstenedione and then to androsterone, but no 5 alpha-dihydrotestosterone or diols could be synthesized from this pathway. neither subcellular ...19817217826
systemic phycomycosis and multiple fibromas in a gray squirrel (sciurus carolinensis). 19817253104
progesterone concentrations in peripheral plasma of non-pregnant and pregnant grey squirrels (sciurus carolinensis).plasma concentrations of progesterone in non-pregnant female grey squirrels were never greater than 3.2 nmol/l and no significant differences were found between levels in anoestrous, pro-oestrous and oestrous animals. during pregnancy, plasma concentrations of progesterone increased significantly and reached a maximum level of 318 nmol/l at around day 35 of the 44 day period of gestation. after parturition, plasma concentrations of progesterone fell sharply. the corpora lutea of pregnancy began ...19817217833
acute fatal toxoplasmosis in squirrels.two dead gray squirrels submitted to the northeastern research center for wildlife diseases ahd nonsuppurative encephalitis and interstitial pneumonitis, with toxoplasma gondii cysts and tachyzoites in many tissues. these infections have rarely been reported from gray squirrels but could mimic clinical rabies.19817327992
prevalence of cuterebra emasculator in squirrels in mississippi.between 1977 and 1979, 1,997 gray squirrels (scriurus carolinensis) and 290 fox squirrels (s. niger) were examined for cuterebra emasculator myiasis. approximately 19% of the gray and 5% of the fox squirrels were infested with 1.9 and 2.5 larvae per host, respectively. myiasis was seen between 14 august and 29 october. peak infestations occurred in the second week of september. adult and subadult squirrels had higher infestations than juveniles. multiple infestations occurred in 51% of the hosts ...19817253103
survey for evidence of colorado tick fever virus outside of the known endemic area in california.a virus very similar or identical to colorado tick fever (ctf) virus was recovered from the blood clot of one of 104 black-tailed jack rabbits (lepus californicus) examined during a survey for various zoonotic agents in mammals and ticks from the university of california, hopland field station, mendocino county, california, 1974--79. this is the first reported isolation of a ctf-like virus from l. californicus, and only the second time such a virus has been found in northwestern california. mend ...19827102919
serologic evidence of jamestown canyon and keystone virus infection in vertebrates of the delmarva peninsula.serological data accumulated during the past decade indicated that a variety of feral and domestic animals of the delaware-maryland-virginia (delmarva) peninsula were infected with jamestown canyon (jc) and/or keystone (key) viruses (bunyaviridae, california serogroup). neutralizing (n) antibody to jc virus was most prevalent in white-tailed deer, sika deer, cottontail rabbits and horses. key virus n antibody was detected most frequently in gray squirrels and domestic goats. n antibody indicativ ...19827149110
visual acuity and spatial contrast sensitivity in tree squirrels.the visual sensitivity of tree squirrels from three different species (two western gray squirrels, sciurus griseus; three fox squirrels, sciurus niger; and an eastern gray squirrel, sciurus carolinensis) was measured for spatial patterns defined by luminance differences. spatial contrast sensitivity functions were determined in behavioral discrimination experiments in which the stimuli were sinusoidally-modulated gratings. at an average luminance level of 3.4 cd/m(2) these squirrels were maximal ...198224923501
cryptosporidiosis in a gray squirrel--. 19827174489
adaptation of gray squirrel behavior to autumn germination by white oak acorns. 198228568235
notoedric mange in gray squirrels (sciurus carolinensis). 19827131658
effect of ovariectomy on the course of gestation in the grey squirrel (sciurus carolinensis).in the grey squirrel pregnancy continues in the absence of the ovaries from day 16 of gestation. since the investigation was performed on squirrels caught in the wild the stage of gestation was estimated from plasma progesterone levels, volume of corpora lutea at ovariectomy and date of parturition for those squirrels which did give birth. three squirrels ovariectomized in early pregnancy did not give birth. plasma progesterone levels after ovariectomy were lower than those found in normal pregn ...19827086328
spermatogenesis in the grey squirrel (sciurus carolinensis) and changes during sexual regression.in the testes of sexually active grey squirrels 8 stages of spermatogenesis were recognized each with a characteristic association of germ cells. the low numbers of spermatozoa in squirrel testes are the result of fewer spermatogonial divisions compared with those of most other mammals as well as a low efficiency of spermatogenesis, with only 42% of the germ cells becoming spermatozoa. a period of testicular regression which may be prolonged follows the breeding season in june/july. in fully reg ...19827077603
myeloid bodies in the mammalian retinal pigment epithelium.in the retinal pigment epithelium (rpe) of a mammal, the eastern gray squirrel, a type of cytoplasmic organelle, the so-called "myeloid body" that was previously thought to be restricted to the rpe of lower vertebrates was observed. in the squirrel, these organelles are continuous with the smooth endoplasmic reticulum (ser), lack an enclosing membrane, and in general exhibit all the morphologic criteria used to identify myeloid bodies. the presumptive myeloid bodies in the squirrel rpe are most ...19836682095
warfarin and the grey squirrel.the anticoagulant warfarin [3-(alpha-acetonylbenzyl)-4-hydroxycoumarin] has been used for controlling the grey squirrel sciurus carolinensis in great britain. before legislation was passed to allow for its use in ireland, it was felt that more information on its effectiveness was required. since the small mammal population of ireland is low, any toxic effects on the native mammal population could greatly deplete the wildlife in ireland. no accurate assessment of the toxicity of warfarin for the ...19836578724
the geniculostriate projection in the grey squirrel: preliminary autoradiographic data.anterograde autoradiographic experiments reveal connectional specificity between the dorsal lateral geniculate (lgn) laminae and striate cortical layers in a rodent, the gray squirrel (sciurus carolinensis). our data indicate that although the geniculostriate projection does not segregate right and left eye information within layer iv, geniculate projections to this layer are tightly organized such that particular cortical substrata receive input from specific lgn layer(s). preliminary data sugg ...19836616208
ultrastructural changes in the prostate gland of a seasonally breeding mammal, the grey squirrel (sciurus carolinensis gmelin).grey squirrels were obtained from the wild every month for two calendar years. the prostate gland was found to be a single lobed structure, subdivided into many lobules each of which was composed of numerous secretory acini with central lumina. secretion was active throughout the breeding season (january to june), but the gland became atrophic from july to september, and recovered between october and december. two 'types' of secretory cells were observed in the secretory epithelium throughout th ...19846706834
malignant mixed (carcinosarcoma) mammary tumor in a gray squirrel. 19846710804
testosterone, 17 beta-hydroxy-5 alpha-androstan-3-one and 4-androstene-3, 17-dione in the plasma of male and female grey squirrels (sciurus carolinensis).extracts of squirrel plasma have been chromatographed on partition columns (using a hydrophilic stationary phase) at atmospheric pressure (celite support) and a reversed phase system at high pressure (hplc). both methods effectively separated testosterone, 17 beta-hydroxy-5 alpha-androstan-3-one (dht) and 4-androstene-3,17-dione; they gave elution patterns that differed considerably. chromatographic mobility of the three androgens on the two systems was identical with that of fractions of squirr ...19846727368
nonintralaminar thalamostriatal projections in the gray squirrel (sciurus carolinensis) and tree shrew (tupaia glis).in mammals, the corpus striatum receives prominent projections from the neocortex and from the intralaminar nuclei of the dorsal thalamus. the present study provides evidence based on anterograde degeneration and axonal transport that the corpus striatum also receives input from two nonintralaminar thalamic nuclei, the pulvinar and the medial geniculate body. each of these nuclei projects to a separate region of the corpus striatum. moreover, the same regions of the corpus striatum that receive ...19846096412
relationships between the nigrotectal pathway and the cells of origin of the predorsal bundle.the goal of this study was to define the anatomical relationships between the terminal field of the nigrotectal pathway and the tectal neurons which project to contralateral brainstem gaze centers by way of the predorsal bundle. the distribution and morphology of the cells of origin for the predorsal bundle were determined by using a modification of the retrograde horseradish peroxidase technique which homogeneously filled their somas and dendrites. the terminal distribution of the nigrotectal t ...19846747028
interhemispheric connections of the visual cortex in the grey squirrel (sciurus carolinensis).the total pattern of visual callosal connections was studied in the grey squirrel by using the fink-heimer technique for axonal and terminal degeneration and the autoradiographic and horseradish peroxidase techniques for axonal transport. the pattern of terminations was correlated with architectonic landmarks. the results show that callosal terminations are distributed in a complex fashion within the visual cortical areas. the major terminations form a band in area 17 along its border with area ...19846200520
seasonal changes in the testes and accessory reproductive organs and seasonal and circadian changes in plasma testosterone concentrations in the male grey squirrel (sciurus carolinensis).a 27-month study of cycles of regression and recrudescence of testis function in adult, grey squirrels in a natural environment in southern england has shown concomitant variation in mean testes weights, mean plasma testosterone concentrations, and mean weights of accessory sex organs, this variation being closely associated with months of the year. testis regression occurred in the period june to august, the exact timing differing among individuals. in 1979-1980 the testes of all squirrels then ...19854018551
the arterially perfused eyecup of the tree squirrel, sciurus carolinensis: a preparation for intracellular recording from mammalian retinal neurons.the arterially perfused eyecup of the eastern gray squirrel, sciurus carolinensis, has been developed for the study of mammalian retinal neurons by the technique of intracellular recording. particular emphasis is placed in this report on the development of a convenient perfusion chamber. the choice of this animal and the reason for choosing the arterially perfused open eyecup are also discussed. intracellular recordings were made from all major types of neurons in the squirrel retina. data are p ...19853999804
anisotropy in the preferred directions and visual field location of directionally-selective optic nerve fibers in the gray squirrel.directionally-selective optic nerve fibers in the gray squirrel possess an anisotropic distribution of preferred direction. similar to the directional anisotropy seen in ground squirrel, the possible role of these units is discussed.19854060616
orchopeas fleas (siphonaptera: ceratophyllidae) of the western gray squirrel, sciurus griseus. 19854078848
response properties of horizontal cells and photoreceptor cells in the retina of the tree squirrel, sciurus carolinensis.a new experimental preparation for intracellular recording from mammalian retinal neurons has been established. this is the arterially perfused eyecup preparation of the tree squirrel, sciurus carolinensis. two horizontal cell types have been recorded in this preparation. these cell types differ in their response waveforms. type 1 horizontal cells appear to receive input only from cones, whereas type 2 horizontal cells receive mixed rod-cone input. sciurus horizontal cells have receptive-field s ...19854078612
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