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Biomedical subjects

B Zernicki

Publications and source records attributed to B Zernicki.

At least 73 records · Page 4Linked to original sources
PubMed1976

Effects of binocular deprivation of pattern vision on single unit responses in the cat superior colliculus.

Single unit responses in the superior colliculus of cats deprived of pattern vision from birth and of normally reared cats were studied in unanesthetized pretrigeminal preparations. Collicular units of deprived cats showed a diminished direction-selectivity but a somewhat better speed-selectivity compared to normals; they also preferred lowspeed stimuli, and reacted less frequently to diffuse flash. The impairment of direction-selectivity of collicular neurons may be partly responsible for the impairment of the pursuit eye movements in visually deprived cats.

Animals↗
PubMed1976

Visual cortex role in object discrimination in cats deprived of pattern vision from birth.

A simultaneous object discrimination task for food reward was elaborated in normal cats and in cats deprived of pattern vision from birth. In the latter the learning was more difficult and retraining was necessary after a preoperative retention period. In both groups the cortical projection of central vision was removed in areas 17, 18 and 19. In deprived cats the deficit following the cortical lesion was less than in normal animals. It is concluded that deprived cats used visual cortex less in learning and thus they learned more slowly but were less deficient postoperatively.

Animals↗
PubMed1976

Activity of some enzymes in the cortex of the cat with pretrigeminal brainstem transection.

The visual and somatic sensory cortex were investigated. The activity of acetylcholinesterase and lactate dehydrogenase was similar in the pretrigeminal and non-operated cats. The activity of these two enzymes, as well as that of choline acetyltransferase, butyrylcholinesterase and acid phosphatase was similar 3 and 8 h after the pretrigeminal transection. Results support the possibility of utilizing the pretrigeminal cat for investigations of biochemical correlates of learning.

Acetylcholinesterase↗
PubMed1976

Electrophoretic patterns of insoluble proteins in the sensory cerebral cortex of visually deprived and normal kittens.

Insoluble proteins were investigated in the visual cortex (area 17) and somatic sensory cortex of one month old kittens. Visual deprivation did not affect the electrophoretic pattern but changed percentage distribution of proteins in both cortices. Some of the alterations seemed to appear only in the visual cortex, which is morphologically and functionally deficient in deprived kittens. Electrophoretic patterns of normal kittens differed from those of normal adult cats.

Age Factors↗
PubMed1975

Single-unit responses to natural objects in area 19 of cats with different early visual experiences.

Cats deprived of pattern vision with hoods and normal cats were used. During the first 3 months of life some hood-reared cats had visual experience with a three-dimensional cross or a ping-pong ball. Recording were performed in adult cats with a pretrigeminal brainstem transection. Unit responses to the cross and the ball were recorded in area 19 within the projection of area centralis. Stimulus-dominance of the exposed object was manifested weakly. Both exposed and control objects activated more units in the experienced hood-reared cats than in hood-reared and normal controls. Compared with previous finding, the present results indicated that early visual experience affects area 19 differently than areas 17 and 18.

Age Factors↗
PubMed1975

Visual discrimination learning in cats with different early visual experiences.

Simultaneous object discrimination learning in an alimentary situation was strongly impaired in cats deprived from birth of patterned visual experience. The same impairment was observed in cats with experience limited to those objects that were used later in the discrimination task. Some impairment was also present in cats which were reared with opened eyes in the laboratory as compared with normal cats, that spent the early period of life outside of the laboratory. It is concluded that the deprived cats were impaired mainly because of the lack of opportunity during early development to use visual cues in alimentary tasks.

Animals↗
PubMed1975

Drive-controlled reflexes: a theory.

Drive-controlled (higher) reflexes are divided in two ways: (i) according to the controlling drive into pain, fear and appetite reflexes; (ii) according to the manner of drive elimination into type A and type B reflexes. A type A reflex simply removes the evoking stimulus, whereas a type B reflex provides a drive-inhibiting stimulus. According to different functions performed in an organism, reflexes are grouped into several systems.

Animals↗
PubMed1973

Chronic pretrigeminal and cerveau isolé cats.

Ten pretrigeminal and ten cerveau isole cats were observed chronically. During 24-36 h sessions EEG activity was continuously recorded and the EEG and ocular responses to visual and olfactory stimuli were studied. In the pretrigeminal cat acute and chronic stages were distinguished, and in the cerveau isole, acute, "early chronic" and "late chronic" stages. During the acute stage, the pretrigeminal cat is continuously awake, whereas the cerveau isole is comatose. During the "early chronic stage", which lasted at least about 3 weeks, the cerveau isole is semicomatose. During the chronic stage in the pretrigeminal cat and the "late chronic stage" in the cerveau isole, the sleep-waking cycle is present. In both preparations alert wakefulness, drowsiness, light .synchronized sleep and deep synchronized sleep occupy, respectively, about 30 percent, 45 percent, 15 percent and 10 percent of the time. Thus, synchronized sleep is strikingly reduced in comparison with an intact cat, while desynchronized sleep is absent.

Animals↗
PubMed1972

Higher reflexes: an attempt at comprehensive classification of neuro-behavioral activity.

The term reflex is used in its widest sense and denotes the neural processes and effector responses controlled by the evoking stimulus and the feedback stimuli. The reflexes having their specific component facilitated by drive central processes are denoted as higher. Escape, avoidance and approach higher reflexes are distinguished: they include, respectively, pain, fear and appetite drive central processes. Approach reflex contains in addition pleasure central processes. Higher reflexes are usually in a chain from. The role of the consummatory stage, which is present is some escape and approach reflexes, is analysed. The reflexes are grouped in several systems according to the particular functions they perform in an organism.

Animals↗