PubMed Health⌕ Search

Biomedical subjects

J Dabrowska

Publications and source records attributed to J Dabrowska.

At least 37 records · Page 2Linked to original sources
PubMed1975

Prefrontal lesions and avoidance reflex differentiation in dogs.

The effects of bilateral partial prefrontal lesions on go-no go differentiation with symmetrical or asymmetrical reinforcement trained by the avoidance procedure were investigated. Moderate impairment of these tasks was observed after large lateral or medial prefrontal lesions, while severe impairment after a deep incision of the fibers in the specific prefrontal region. It is suggested that the mechanism of avoidance differentiation is of a symmetrical type, which is directly related to the "motor act differentiation" but not to the drive-no drive differentiation.

Animals↗
PubMed1975

Comparison of the septal lesion effects on visual and spatial discriminations in rats.

Postoperative performance in acquisition and reversal learning of septal rats was investigated and compared with control rats in three experiments. Experiment I involved a simultaneous black-white discrimination task. The number of errors in normal and septal rats was similar in acquisition and reversal learning. Both septal and normal rats manifested directional response sets. Experiment II examined a position habit discrimination. Acquisition was similar in septal and normal rats, while reversal learning was impaired in septal rats. Experiment III, which investigated a position habit discrimination with available irrelevant visual stimuli indicated that both acquisition and reversal learning were impaired in operated animals. Results suggested that septal rats utilize response produced cues to control their behavior, but the enhanced orienting response to the visual stimuli interferes with the proprioceptive stimuli.

Animals↗
PubMed1975

Effects of partial prefrontal lesions in dogs on go-no go avoidance reflex differentiation and reversal learning.

The effects of prefrontal medial or lateral lesions on the retention of avoidance go – no go click-tone differentiation in dogs were studied. The acquisition of the differentiation was influenced by the quality of the stimuli since more errors were performed to the click CS(-) than to the tone CS(-). Neither medial nor lateral lesions exerted any effect on retention of the differentiation. Similarly, as during original differentiation training, the quality of the stimuli had an effect on reversal learning in normal dogs. Such an effect was markedly reduced in dogs with prefrontal lesions and more strongly in those Ss which received lateral lesions. The results were discussed relative to data obtained from cats trained under similar conditions. The dogs showed better responding on positive trials while performance in cats was better on negative trials. The stimulus quality effect was more pronounced in dogs during negative, and in cats during positive trials.

Animals↗
PubMed1975

Effect of vibration on sulfomucopolysaccharide metabolism in the eye.

The metabolism of 35S sodium sulfate was studied in the eyes of guinea pigs and rabbits subjected to vibration. The investigations included determination of radioactivity of whole eyeballs of guinea pigs and in single eyeball tunics of rabbits, i.e., retina-choroid-sclera investigated jointly as a tissue complex, and cornea and lens studied separately, besides that, autoradiographic investigations were performed. The animals were subjected to a vertical, sinusoidal vibration of 42 Hz. frequency and 1 mm. amplitude. The duration of one exposure was three hours and they were repeated daily for three to six days. Incorporation of the isotope into the eyeballs of animals subjected to vibration was decreased and this decrease was related to the length of exposure suggesting that vibration changes the metabolism of sulfomucopolysaccharides in the eye.

Animals↗
PubMed1972

Partial prefrontal lesions and go-no go symmetrically reinforced differentiation test in dogs.

The effects of partial bilateral lesions situated in the prefrontal region on go-no go differentiation with symmetrical reinforcement were investigated in dogs. Bilateral removals of proreal gyri and medial cortical surface involving pregenual, genual, precruciatal (XM), subcallosal or medial subproreal areas did not impair performance of this test. Very small cortical lesions of proreal areas located under presylvian fissure impaired transiently the differentiation. Removals of the orbital gyri to the presylvian fissure caused severe and long lasting impairment of this differentiation. It was concluded that the orbital areas situated on the lateral aspect of the hemisphere in dogs was responsible for correct performance of go-no go symmetrically reinforced differentiation task.

Animals↗
PubMed1972

On the mechanism of go-no go symmetrically reinforced task in dogs.

The mechanism of differentiation with asymmetrical and symmetrical reinforcement was analysed on the basis of different impairments after medial and lateral prefrontal lesions. The medial prefrontal lesions impaired the retention of asymmetrical differentiation whereas the symmetrical differentiation was slightly or not impaired at all. The lateral prefrontal lesions impaired moderately the asymmetrical differentiation only with short intertrial intervals. The disturbances of symmetrical differentiation depended on the quality of the stimuli, the separation of their sources and the quality of instrumental responses. The results support the hypothesis that the medial prefrontal cortex is involved in inhibitory control of alimentary drive functions. It is concluded that the lateral prefrontal cortex takes part in the elaboration of direct connections between conditioned stimuli and instrumental responses.

Animals↗
PubMed1971

Dissociation of impairment after lateral and medial prefrontal lesions in dogs.

Dogs were trained before operation on a go, no-go test with symmetrical reinforcement. Lesions situated on the medial surface of the prefrontal cortex caused slight or no impairment in retention, whereas removal of the lateral prefrontal cortex induced severe and long-lasting impairment. The lateral prefrontal cortex is probably related to selection of the proper instrumental responses to corresponding stimuli.

Animals↗