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Biomedical subjects

W Wyrwicka

Publications and source records attributed to W Wyrwicka.

At least 19 recordsLinked to original sources
PubMed1986

Quinine tolerance during self-stimulation in cats.

Thirsty cats, offered a choice between distilled water and quinine solution, preferred the latter to distilled water and accepted quinine concentrations greater than those they accepted in control sessions when drinking quinine solution was rewarded by hypothalamic stimulation, whereas drinking distilled water was not. When the same stimulation rewarded drinking distilled water only, the cats switched to distilled water and refused quinine solutions at concentrations even less than those previously accepted in control sessions. It was concluded that drinking quinine solution was an instrumental response which secured the desirable hypothalamic stimulation.

Animals↗
PubMed1986

Hypothalamic substrates of self-stimulation in cats.

The purpose of this study was to gather anatomical data concerning sites for self-stimulation in the lateral hypothalamus in the cat. The study was conducted on 25 adult cats. In each cat, one to three monopolar stimulating electrodes were implanted bilaterally in the lateral hypothalamus in a region between sections Fr 10.0 and Fr 13.0, L 2.0 and L 5.0, and H -2.0 and H -6.0. A reference electrode was placed in the calvaria over the frontal sinus. Twenty-two of these cats learned to press a lever when each press was rewarded by a brief (0.3 s) electrical stimulus (2.0 to 7.0 V, 100/s, 1 ms duration per pulse) delivered to the hypothalamus. Postmortem anatomical analysis of the brains revealed that most of the positive rewarding sites were located in a midlateral hypothalamic zone, which included the medial forebrain bundle, and were localized to section Fr 11.5, between L 2.0 and L. 5.0, and H -3.0 and H -5.5.

Animals↗
PubMed1975

The process of conditioning: an evolving concept.

Various explanations of the process of conditioning and some models of the postulated connections between brain centers are discussed. Some results of research on conditioning processes at the neuronal level are reviewed. A hypothesis is put forth that conditioned behavior is a result of activation of neural patterns of associations between the sensory traces of stimuli; such neural patterns may be stored in polysensory neurons. Models based on this hypothesis are presented.

Animals↗
PubMedDate not supplied

The sensory nature of reward in instrumental behavior.

Improvement in the sensory state, or "better-being," achieved either through obtaining desirable sensations or through escaping undesirable sensations, is considered the essential value which maintains the instrumental behavior. This value may vary depending on such factors as the intensity of the stimulus producing sensations, the effects of its previous occurrence, and the changes in the internal and external environment. Methods of evaluation of sensory "better-being" by means of measuring instrumental, autonomic and EEG responses are discussed.

Animals↗