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At least 919 records · Page 51Linked to original sources
PubMed1993

Effectiveness of buspirone on urine spraying and inappropriate urination in cats.

The most frequent type of behavior problem in cats for which veterinary consultation is sought is problem urination. Urine spraying and urine marking have been treated by use of long-acting progestins and diazepam, a benzodiazepine antianxiety drug. Effectiveness of the nonbenzodiazepine antianxiety drug, buspirone, in suppressing urine spraying and marking in 47 male and 15 female cats was evaluated. The effect of the drug in correcting inappropriate urination in 9 cats also was evaluated. Buspirone resulted in a favorable response (> 75% reduction) in 55% of cats treated for urine spraying or marking. There was no sex difference in effectiveness of the treatment, but cats from single-cat households responded favorably significantly (P < 0.001) less frequently than those from multiple-cat households. The 55% response rate was within the range of treatment effectiveness that has been reported for diazepam, and was greater than that reported for progestin. In contrast to diazepam, with which over 90% of treated cats resumed spraying or marking when the drug was gradually discontinued, only half of the cats treated with buspirone resumed spraying when the drug was discontinued after 2 months of treatment (P < 0.001). This difference between diazepam and buspirone in resumption of urine spraying was attributed to diazepam's induction of physiologic and behavioral dependency, not found with buspirone. Cats that resumed spraying were placed on long-term treatment ranging from 6 to 18 months. Buspirone also did not cause the adverse effects of sedation and ataxia, which commonly are seen with diazepam treatment. In cats treated for inappropriate urination, 56% returned to normal litter box usage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

Effect of illness not associated with the thyroid gland on serum total and free thyroxine concentrations in cats.

OBJECTIVE: To determine circulating concentrations and fate of total and free thyroxine (T4) in cats with various illnesses not associated with the thyroid glands (nonthyroidal illnesses). DESIGN: Prospective study. ANIMALS: 98 cats with nonthyroidal illness and 50 clinically normal cats. PROCEDURE: Serum total T4 concentrations were measured by radioimmunoassay, and serum free T4 concentrations were measured by direct equilibrium dialysis. Free T4 fraction was calculated from these 2 values. RESULTS: Serum total T4 concentrations were significantly (P < 0.001) lower in sick cats (mean +/- SD, 17.18 +/- 8.14 nmol/L), compared with healthy cats (mean +/- SD, 26.00 +/- 7.62 nmol/L). Serum total T4 concentrations were inversely correlated with mortality. Differences in serum free T4 concentrations in sick cats (mean +/- SD, 27.70 +/- 13.53 pmol/L), compared with healthy cats (mean +/- SD, 24.79 +/- 8.33 pmol/L), were not significant. A few sick cats had serum free T4 concentrations greater than the reference range. Calculated free T4 fraction was significantly (P < 0.001) greater in sick cats (mean +/- SD, 0.24 +/- 0.30%), compared with healthy cats (mean +/- SD, 0.10 +/- 0.06%). CLINICAL IMPLICATIONS: Euthyroidism is maintained in sick cats, despite low serum total T4 concentrations. Measurement of serum total T4 concentrations is a valuable prognostic indicator. Serum free T4 concentrations should be used cautiously as a sole diagnostic criterion for confirmation of hyperthyroidism.

Animals↗
PubMed1996

Clinical and serologic evaluation of cats with cryptococcosis.

OBJECTIVE: To evaluate the long-term clinical outcomes and serologic changes in cryptococcal antigen and antibody titers in cats with confirmed Cryptococcus neoformans infection. DESIGN: Prospective case series. ANIMALS: 47 cats with cryptococcosis. PROCEDURE: Cats included in this study were determined to have cryptococcosis on the basis of identification of C neoformans on histologic or cytologic examination, isolation of C neoformans in culture, or positive serologic test results for cryptococcal antigens. Information concerning the signalment, history, physical examination findings, FeLV and feline immunodeficiency virus status, serologic testing, treatment, and outcome for each cat was requested on a survey form. Follow-up measurements of serum cryptococcal antigen and antibody titers were requested for all surviving cats. RESULTS: Signalment and clinical signs of cats with cryptococcosis reported here were consistent with previous reports. Treatment consisted primarily of azole antifungal drugs. All cats were seronegative for cryptococcal antibody titers, whether tested initially or at follow-up examination. All but 1 cat tested were seropositive for cryptococcal antigens when initially tested. Cats with and without clinical signs of C neoformans infection were seropositive for cryptococcal antigens months to years after initial diagnosis of cryptococcosis. CLINICAL IMPLICATIONS: The results of this study indicate that serum titers to cryptococcal antigens in cats can persist with or without clinical signs for months to years after an initial diagnosis of cryptococcosis is made. Repeated evaluation of serum cryptococcal antigen titers is advised during the treatment of cats to monitor progress, evaluate prognosis, and guide cessation of treatment.

Animals↗
PubMed1997

Intensive 50-week evaluation of glipizide administration in 50 cats with previously untreated diabetes mellitus.

OBJECTIVE: To evaluate use of the oral hypoglycemic drug glipizide in diabetic cats. DESIGN: Prospective study. ANIMALS: 50 cats with recently diagnosed but untreated diabetes mellitus. PROCEDURE: Each cat received glipizide (5 mg, q 12 h) for 16 weeks. Medication was not given during the subsequent 16 weeks; then glipizide treatment was repeated. Each cat was evaluated prior to treatment and at 2, 4, 8, 12, and 16 weeks during each of the 3 phases: blood samples for serum glucose and insulin determinations were obtained every 2 hours, from 8 AM to 6 PM. A preprandial blood glycosylated hemoglobin percentage was determined for the first sample obtained at each visit. RESULTS: During the first 22 weeks of the study, diabetes worsened in 28 of the 50 cats, which then were disqualified from the study and treated with insulin. Of the remaining 22 cats that improved clinically, 7 had corresponding metabolic improvement in each diabetes-related parameter assessed and did not become hypoglycemic. Six of the 22 cats became hypoglycemic. Glipizide was discontinued, and diabetes did not recur. Serum glucose concentration did not improve in 6. Three cats had metabolic and clinical improvement during initial glipizide treatment, but had recurrence of the disease during repeated treatment; glipizide was discontinued and insulin was administered. None of the 50 treated cats died, and observed morbidity was mild and transient. Transient anorexia and vomiting were observed in 8 cats, and 4 became transiently icteric with abnormal liver enzyme activities. CLINICAL IMPLICATIONS: Trial use of glipizide is feasible in diabetic cats of owners who are unable or unwilling to administer insulin.

Animals↗
PubMed1997

Relapsing bacteremia after blood transmission of Bartonella henselae to cats.

OBJECTIVES: To determine persistence of bacteremia, pathogenicity, and immunoglobulin kinetics after blood transmission of Bartonella henselae in cats. ANIMALS: 18 specific-pathogen-free (SPF) cats (16 weeks old) received blood or urine from 4 adult cats (2 SPF, 2 naturally infected with B henselae). PROCEDURE: SPF cats were inoculated with blood IV (n = 4), blood IM (n = 4), or urine sediment IM (n = 4) from 2 bacteremic cats (donors A and B). Control cats (2/route) received inoculum from culture-negative, seronegative SPF cats (donors C and D). RESULTS: 6 cats (5 blood, 1 urine) were transiently febrile during the 213-day observation period. Two bacteremic cats developed CNS abnormalities. Transient anemia was the only hematologic abnormality. Bacteremia was induced in 7 of 8 blood recipients by postinoculation day (PID) 11. Urine recipients (n = 6) did not become bacteremic or seroconvert by PID 108, but when challenge exposed IV with blood, 4 of 6 became infected. All infected cats developed relapsing bacteremia. Initially, colony counts for donor-A recipients were 10(3) greater than those for donor-B recipients; however, during relapses, counts were similar. Polymerase chain reaction-restriction fragment length polymorphism analysis of 16S rRNA gene and the intergenic spacer region revealed no differences among isolates derived from recipient cats. Bartonella henselae-specific antibodies were detected between PID 15 and 18 in donor-A, compared with PID 46 and 181 in donor-B recipients. The peak geometric mean titer of donor-A recipients was 1,448, versus 406 for donor-B recipients. CONCLUSIONS AND CLINICAL RELEVANCE: Blood transmission of B henselae induced subtle clinical abnormalities; the biological behavior of the 2 donor strains differed; and relapsing bacteremia can persist in conjunction with variably high antibody titers.

Animals↗
PubMed1997

Complications associated with use of jejunostomy tubes in dogs and cats: 40 cases (1989-1994).

OBJECTIVE: To evaluate complications and outcomes of surgeries in which jejunostomy tubes were used in critically ill dogs and cats. DESIGN: Retrospective review of medical records. ANIMALS: 32 dogs and 8 cats. PROCEDURE: In each animal, a 5-F or 8-F red rubber urethral/feeding catheter was surgically placed in the proximal portion of the jejunum. RESULTS: The most common indication for jejunostomy tube placement in dogs was a gastrointestinal condition (20 dogs; 62.5%). Neoplasms were detected in 11 of the 20 dogs. Pancreatic disease was the most common indication for tube placement in cats (7 cats; 87.5%). Thirty-three animals (27 dogs, 6 cats; 82.5%) did not have complications. Five dogs and 2 cats had 10 tube-related complications, including focal cellulitis (3 dogs), tube dislodgement (2 dogs, 1 cat), and tube occlusion (1 dog, 1 cat). Twenty-four animals (20 dogs, 4 cats; 60%) were discharged from the hospital. Fifteen dogs and 4 cats were alive 2 weeks after discharge, and 5 dogs and 2 cats survived for at least 4 weeks after discharge. Deaths were related to disease and were not associated with jejunostomy tubes. CLINICAL IMPLICATIONS: The complication rate associated with jejunostomy tubes appears to be low. Complications usually are nonfatal.

Animals↗
PubMed1997

Insulin overdose in dogs and cats: 28 cases (1986-1993).

OBJECTIVE: To characterize the frequency, medical history, clinical signs, methods of treatment, and outcome of insulin-induced hypoglycemia and to identify predisposing factors. DESIGN: Retrospective study. ANIMALS: 8 dogs and 20 cats with diabetes mellitus that developed hypoglycemia because of insulin overdose. PROCEDURE: Medical records of dogs and cats receiving insulin for treatment of diabetes mellitus were reviewed. Medical records of dogs and cats that had an episode of hypoglycemia were reviewed in detail. RESULTS: Overdosing of insulin was more common in cats than in dogs. Median weight of diabetic cats that became hypoglycemic was significantly greater than that of the hospital population of diabetic cats at diagnosis. Eighty percent of cats that became hypoglycemic were receiving insulin doses > 6 U/injection, administered once or twice daily. Dose and type of insulin did not correlate with duration or severity of hypoglycemia. In 7 of 8 dogs and 10 of 20 cats, management factors or concurrent medical problems were considered to be predisposing causes for insulin overdose. Two dogs and 2 cats did not have clinical signs of hypoglycemia, despite documented low concentrations of glucose in their blood. CLINICAL IMPLICATIONS: Diabetic cats, especially if obese, are at greater risk of insulin overdose than are diabetic dogs. The reason for overdose may not be evident. Diabetic dogs and cats may become hypoglycemic without developing autonomic warning signs of hypoglycemia, or these signs may not be recognized (hypoglycemia unawareness).

Animals↗
PubMed1997

Malignant colonic neoplasia in cats: 46 cases (1990-1996).

OBJECTIVE: To evaluate a group of cats with malignant colonic neoplasia and to identify factors related to survival time. DESIGN: Retrospective study. ANIMALS: 46 cats with malignant colonic neoplasia. PROCEDURE: Information on signalment, diagnostic findings, histopathologic diagnosis, surgical procedure performed, identification of nodal metastasis at surgery, type of chemotherapy administered, and survival time was obtained from the medical record of each cat. A diagnosis of malignant colonic neoplasia had been established by histologic examination of endoscopic biopsy specimens (3 cats), biopsy specimens obtained during laparotomy (38), or necropsy specimens (5). RESULTS: Mean age of cats was 12.5 years (range, 6 to 18 years). Ultrasonography was useful 84% of the time in localizing the mass to the intestine. Three cats had endoscopic biopsy, 9 had incisional biopsy, 21 had mass resection, and 8 had subtotal colectomy performed. Histopathologic diagnoses included adenocarcinoma (21 cats), lymphoma (19), mast cell tumor (4), and neuroendocrine carcinoma (2). CLINICAL IMPLICATIONS: Obtaining clean margins at surgery seems to increase survival time in cats with malignant colonic neoplasia. Metastasis at the time of surgery decreases survival time. Data from this study indicate that the survival time of certain cats with colonic lymphoma may not be affected by chemotherapy. Cats with an unidentified colonic mass should receive a subtotal colectomy to increase survival time. Cats with colonic adenocarcinoma should receive a subtotal colectomy with consideration of doxorubicin administration to increase survival time.

Adenocarcinoma↗
PubMed1998

Amitriptyline treatment for severe recurrent idiopathic cystitis in cats.

OBJECTIVE: To evaluate the safety and efficacy of amitriptyline hydrochloride in the treatment of severe recurrent idiopathic cystitis (IC) in cats. DESIGN: Prospective study. ANIMALS: 15 cats with IC that failed to respond to other treatments. PROCEDURE: Each cat received 10 mg of amitriptyline, PO, every 24 hours in the evening for 12 months or until signs recurred. Urinalysis, CBC, serum biochemical analysis, urine bacteriologic culture, and cystoscopy were performed initially, and after 6 and 12 months in responders. Severity scores of owner-observed signs of lower urinary tract (bladder and urethra) disease were recorded. RESULTS: During the first 6 months of treatment, 11 of the 15 cats had no owner-observed signs of lower urinary tract disease. During the next 6 months, 9 of 15 cats remained free of signs of cystitis. Despite clinical improvement, cystoscopic abnormalities persisted in all cats at the 6- and 12-month evaluations. Hematuria and proteinuria were decreased at the 12-month evaluation compared with the initial evaluation. Two of 15 cats initially appeared somnolent after amitriptyline treatment. Of 9 cats completing the study, 7 had increased body weight and 8 had decreased coat quality compared with the initial evaluations. Four cats developed small cystic calculi during the first 6 months of the study. Serum biochemical or hematologic abnormalities were not detected during the study. CLINICAL IMPLICATIONS: Amitriptyline treatment successfully decreased clinical signs of severe recurrent IC in 9 of 15 cats treated. Somnolence, weight gain, decreased grooming, and transient cystic calculi were observed during treatment in some cats.

Adrenergic Uptake Inhibitors↗
PubMed1999

Plasma amino acid profiles in cats with naturally acquired chronic renal failure.

OBJECTIVE: To characterize potential changes in preprandial plasma amino acid concentrations in cats with naturally acquired chronic renal failure (CRF), compared with healthy cats, and to assess potential effects of the severity of renal failure on plasma amino acid concentrations in these cats. ANIMALS: 62 adult cats. PROCEDURE: Preprandial plasma amino acid concentrations were evaluated in 38 cats with mild, moderate, or severe CRF and in 24 apparently healthy cats. Effects of severity of renal failure, amount of dietary protein, degree of weight loss, appetite, and body condition on plasma amino acid profiles were evaluated. RESULTS: Cats with various stages of CRF had significantly (P< 0.05) decreased plasma concentrations of o-hydroxyproline, glutamate, proline, glycine, alanine, tyrosine, tryptophan, and arginine, and significantly increased plasma concentrations of asparagine, citrulline, ornithine, 1-methylhistidine, and 3-methylhistidine. Significant (P < 0.05) alterations in amino acid concentrations also were identified when cats with CRF were grouped by appetite or severity of renal disease. Amount of dietary protein, body condition, or degree of weight loss had no significant effect on plasma amino acid concentrations. CONCLUSIONS: Compared with those in healthy cats, preprandial plasma amino acid profiles in cats with mild, moderate, or severe CRF are abnormal. CLINICAL RELEVANCE: Despite frequency of altered plasma amino acid concentrations in cats with CRF, the magnitude of these changes is mild and of little clinical relevance. Short-term use of a commercial protein-restricted diet has no deleterious effects on plasma amino acid concentrations.

Amino Acids↗
PubMed2002

Exposure to dogs and cats in the first year of life and risk of allergic sensitization at 6 to 7 years of age.

CONTEXT: Childhood asthma is strongly associated with allergic sensitization. Studies have suggested that animal exposure during infancy reduces subsequent allergic sensitization. OBJECTIVE: To evaluate the relationship between dog and cat exposure in the first year of life and allergic sensitization at 6 to 7 years of age. DESIGN, SETTING, AND SUBJECTS: Prospective birth cohort study of healthy, full-term infants enrolled in a health maintenance organization in suburban Detroit, Mich, who were born between April 15, 1987, and August 31, 1989, and followed up yearly to a mean age of 6.7 years. Of 835 children initially in the study at birth, 474 (57%) completed follow-up evaluations at age 6 to 7 years. MAIN OUTCOME MEASURES: Atopy, defined as any skin prick test positivity to 6 common aeroallergens (dust mites [Dermatophagoides farinae, D pteronyssinus], dog, cat, short ragweed [Ambrosia artemisiifolia], and blue grass [Poa pratensis]); seroatopy, defined as any positive allergen-specific IgE test result for the same 6 allergens or for Alternaria species. RESULTS: The prevalence of any skin prick test positivity (atopy) at age 6 to 7 years was 33.6% with no dog or cat exposure in the first year of life, 34.3% with exposure to 1 dog or cat, and 15.4% with exposure to 2 or more dogs or cats (P =.005). The prevalence of any positive allergen-specific IgE test result (seroatopy) was 38.5% with no dog or cat exposure, 41.2% with exposure to 1 dog or cat, and 17.9% with exposure to 2 or more dogs or cats (P =.003). After adjustment for cord serum IgE concentration, sex, older siblings, parental smoking, parental asthma, bedroom dust mite allergen levels at 2 years, and current dog and cat ownership, exposure to 2 or more dogs or cats in the first year of life was associated with a significantly lower risk of atopy (adjusted odds ratio, 0.23; 95% confidence interval, 0.09-0.60) and seroatopy (adjusted odds ratio, 0.33; 95% confidence interval, 0.13-0.83). CONCLUSION: Exposure to 2 or more dogs or cats in the first year of life may reduce subsequent risk of allergic sensitization to multiple allergens during childhood.

Allergens↗
PubMed1994

Comparative biochemical characteristics of the cat and rabbit urinary bladder.

The cat and the rabbit are two of the most popular models for the study of lower urinary bladder function. The cat has been used extensively for in vivo studies of spinal and supra-spinal micturition reflexes. In contrast, the rabbit has been used extensively for the in vitro study of bladder function. Although the cat and rabbit bladders are approximately the same mass, the cat bladder can generate approximately 6 times the intravesical pressure than the rabbit bladder at the same volume (in vitro response to field stimulation). In order to determine if the increased pressure generation is related to increased cellular energetics, we compared the intracellular concentrations of ATP and creatine phosphate (CP), and the enzyme activities of three enzymes which have important functions in cellular energetics: creatine kinase, citrate synthase, and malic dehydrogenase between the cat and rabbit urinary bladder. The results can be summarized as follows: (1) The bladder weight of the cat and rabbit are similar. (2) The isolated cat bladder can generate approximately 6 times the intravesical pressure of the isolated rabbit bladder. (3) The ATP and CP concentrations of the rabbit are significantly greater than the concentrations in the cat bladder. (4) The hydroxyproline concentration is significantly greater in the cat than the rabbit. (5) The maximum activities of creatine kinase, citrate synthase, and malic dehydrogenase are significantly lower in the cat than the rabbit. In general, it is clear that the ability of the cat to generate high intravesical pressures is not correlated with increased tissue high energy phosphate concentrations, or high enzymatic activities of three specific cytosolic or mitochondrial enzymes.

Adenosine Triphosphate↗
PubMed1987

D-[3H]aspartate retrograde labelling of callosal and association neurones of somatosensory areas I and II of cats.

Experiments were carried out on cats to ascertain whether corticocortical neurones of somatosensory areas I (SI) and II (SII) could be labelled by retrograde axonal transport of D-[3H]aspartate (D-[3H]Asp). This tritiated enantiomer of the amino acid aspartate is (1) taken up selectively by axon terminals of neurones releasing aspartate and/or glutamate as excitatory neurotransmitter, (2) retrogradely transported and accumulated in perikarya, (3) not metabolized, and (4) visualized by autoradiography. A solution of D-[3H]Asp was injected in eight cats in the trunk and forelimb zones of SI (two cats) or in the forelimb zone of SII (six cats). In order to compare the labelling patterns obtained with D-[3H]Asp with those resulting after injection of a nonselective neuronal tracer, horseradish peroxidase (HRP) was delivered mixed with the radioactive tracer in seven of the eight cats. Furthermore, six additional animals received HRP injections in SI (three cats; trunk and forelimb zones) or SII (three cats; forelimb zone). D-[3H]Asp retrograde labelling of perikarya was absent from the ipsilateral thalamus of all cats injected with the radioactive tracer but a dense terminal plexus of anterogradely labelled corticothalamic fibres from SI and SII was observed, overlapping the distribution area of thalamocortical neurones retrogradely labelled with HRP from the same areas. D-[3H]Asp-labelled neurones were present in ipsilateral SII (SII-SI association neurones) in cats injected in SI. In these animals a bundle of radioactive fibres was observed in the rostral portion of the corpus callosum entering the contralateral hemisphere. There, neurones retrogradely labelled with silver grains were present in SI (SI-SI callosal neurones). Association and callosal neurones labelled from SI showed a topographical distribution similar to that of neurones retrogradely labelled with HRP. The laminar patterns of corticocortical neurones labelled with D-[3H]Asp or with HRP were also similar, with one exception. In the inner half of layer II, SII-SI association neurones and SI-SI callosal neurones labelled with the radioactive marker were much less numerous than those labelled with HRP. In cats injected in SII, D-[3H]Asp retrogradely labelled cells were present in ipsilateral SI (SI-SII association neurones). Their topographical and laminar distribution overlapped that of neurones labelled with HRP but, as in cats injected in SI, association neurones labelled with silver grains were unusually rare in the inner layer III.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2001

The effect of early specific feeding on food conditioning in cats.

Four cats were fed with beef only (beef cats) and 4 cats were fed with tuna only (tuna cats) during the first 6 months of their lives. Thus, they were deprived of a variety of food tastes. The cats then were trained in instrumental conditioning. After criterion performance was achieved, they were retrained with alternated food: In the beef cats, tuna was used, and in tuna cats, beef was used. There were six stages with alternated food. The beef cats acquired a pushing response markedly slower than the tuna cats because they often refused to eat the beef reward. Moreover, both the beef and the tuna cats preferred tuna in stages with alternated food. In contrast, there was no difference in attractiveness between beef or tuna in another 4 cats nondeprived of a variety of food tastes. Hence, early deprivation of a variety of food tastes may reveal an inborn food preference.

Aging↗
PubMed2002

Mammalian ear specializations in arid habitats: structural and functional evidence from sand cat (Felis margarita).

To test whether structural specializations of sand-cat ears are adaptations to their desert habitats we measured structural and acoustic features of their ears. The area of the external ear's pinna flange is similar to that of domestic cat. The dimensions of the ear canal are about twice domestic cat's, as is the volume of the middle-ear air space. The magnitude of the acoustic input-admittance at the tympanic membrane is about five times larger than that of domestic cat; both the middle-ear cavities and the ossicular chain contribute to the increase. Structure-based models suggest the acoustic admittance looking outward through the external ear is generally larger for sand cat than for domestic cat; the radiation power-efficiency is also larger in sand cat for frequencies below 2 kHz. Hearing sensitivity (estimated from measurements and model calculations) in sand cat is predicted to be about 8 dB greater than in domestic cat for frequencies below 2 kHz. Analysis of attenuation of sound in deserts implies that the increased sensitivity extends sand cat's hearing range beyond domestic cat by 0.4 km at 0.5 kHz. Thus, the structural specializations may provide habitat-specific survival value.

Acoustic Stimulation↗
PubMed1975

Visual discrimination of flux-equated figures by cats with brain lesions.

Cats with various brain lesions were compared in their abilities to learn or relearn for food reward to a strict performance criterion a simple dark--light discrimination and 3 sets of discriminations between pairs of triangle equated for overall luminous flux. The results revealed a spectrum of deficits in visual learning by cats with different lesions and indicate: (1) cats with bilateral lesions of the superior colliculus-pretectum can learn dark-light and geometric figure discriminations in approximately the same number of training trials as unoperated cats or as cats with bilateral lesions of the lateral-posterolateral and splenial gyri; (2) cats with bilateral lesions of the superior colliculus-pretectum can learn to discriminate from a distance between geometric figures equated for overall luminous flux; (3) cats with bilateral lesions of the suprasylvian and ectosylvian gyri in addition to the lateral-posterolateral and splenial gyri require more training to learn both types of visual discriminations than unoperated cats or cats with lesions either of the superior colliculus-pretectum or of the lateral-posterolateral and splenial gyri; (4) cats require either an intact superior colliculus-pretectum or intact lateral-posterolateral and splenial gyri in order to discriminate between geometric figures; (5) cats with bilateral lesions of the posterior two-thirds--three-fourths of the neocortex and most of the superior colliculus-pretectum can learn a simple dark-light discrimination after prolonged training.

Animals↗
PubMed1981

Distractibility of cats with lesions of the superior colliculus-pretectum during performance of a 4-choice visual discrimination.

(1) Intact cats and cats with bilateral lesions of the superior colliculus-pretectum were trained on 4-choice, luminous flux discriminations in an apparatus consisting of a 6-foot square open field with 4 stimulus panels along one wall. After cats attained a high performance criterion on a 4-choice dark-light discrimination they were tested for 'distractibility' by flashing a light behind one of the stimulus panels. (2) All intact cats and cats with lesions of the superior colliculus-pretectum learned the 4-choice luminous flux discriminations. Cats with lesions of the superior colliculus-pretectum, however, followed longer paths and had longer latencies to the correct door, even after attaining criterional performance. (3) All intact cats and cats with lesions of the superior colliculus-pretectum were distracted by the flashing light, as indicated by increased commission of errors, increased path lengths and increased response latencies on trials in which the distracting stimulus was presented. However, both intact cats and cats with lesions of the superior colliculus-pretectum habituated to the distracting stimulus. (4) These results are consistent with previous findings that cats with lesions of the superior colliculus-pretectum have difficulty in withholding incorrect responses or in shifting attention or response tendencies from the incorrect to the correct stimulus. (5) These results do not support the hypothesis that lesions of the superior colliculus produce deficits in attention as measured by distractibility to novel stimuli.

Animals↗
PubMed1988

Functional influence of areas 17, 18, and 19 on lateral suprasylvian cortex in kittens and adult cats: implications for compensation following early visual cortex damage.

The aim of the present study was to investigate the mechanisms of physiological compensation that is seen in the posteromedial lateral suprasylvian (PMLS) cortex of cats that received visual cortex (areas 17, 18, and 19) damage early in life. The strategy was to compare the response properties of PMLS neurons just after visual cortex damage (before any compensation has occurred) with the properties of PMLS neurons in normal cats and cats with long-standing visual cortex damage. Fourteen animals (aged 8 weeks, 18 weeks, 26 weeks, or adult) received a unilateral visual cortex lesion and recordings were made from ipsilateral PMLS cortex within about 24 h. An additional 4 adult cats were studied within either 24 or 3 h of a bilateral visual cortex lesion. Results from these animals were compared with results from normal cats and cats with long-standing visual cortex damage studied previously in this laboratory. At all ages studied, an acute visual cortex lesion reduced the percentage of direction-sensitive cells in PMLS cortex from nearly 80% in normal cats to about 20% after the lesion. In 8- and 18-week-old kittens, nearly all of the remaining PMLS cells responded best to stimulus movement but were not direction sensitive. In 26-week-old and adult cats, the remaining cells were divided between those that responded to movement without a directional preference and those that responded as well to stationary flashed stimuli as to moving stimuli. The presence of receptive-field surround inhibition was not affected significantly by an acute lesion at any age. In addition, few PMLS cells were orientation selective to elongated slits of light in cats with an acute lesion, just as in normal cats. The ocular dominance distributions of PMLS neurons also were normal following an acute visual cortex lesion at all ages studied. These results suggest that the influences of areas 17, 18, and 19 on the response properties of PMLS neurons are the same when the properties first reach maturity as in adult cats. The results also suggest that the mechanisms of physiological compensation for an early visual cortex lesion differ for different response properties. Compensation of direction sensitivity and orientation selectivity (an anomalous property) develops de novo after the early lesion. In contrast, compensation of ocular dominance appears to be due to the maintenance of a preexisting property that is present immediately after the lesion. Thus, plasticity after early visual cortex damage represents multiple developmental changes in the remaining visual pathways.

Aging↗