Interactions between neurons in the amygdala and hypothalamus during conditioned reflex behavior involving choice of reinforcement quality in cats.

The organization of distributed amygdalo-hypothalamic and local amygdalar and hypothalamic neural networks was studied in three cats, trained to perform a food-related operant conditioned reflex to light by the "active choice" of reinforcement quality method; pressing the pedal with a short latent period provided the cats with a bread/meat mixture, while pressing with a long latent period yielded meat. Animals showed sharp differences in their individual abilities to choose one or the other reinforcement. Two cats preferred long-latency pedal-pressing to obtain meat, and were considered to be "self-controlled," while the third cat, which preferred short-latency pedal-pressing to obtain the less valuable reinforcement (the bread/meat mixture) was described as "impulsive." Chronically implanted semimicroelectrodes were used to record multineuron activity in the basolateral nucleus of the amygdala and the lateral nucleus of the hypothalamus. Interactions between the discharge trains of neighboring and distant neurons were assessed by cross-correlation analysis. Interneuron functional connections were found to predominate significantly in the local neural networks of the basolateral amygdala and distributed amygdalar-hypothalamic networks in the "impulsive" animal as compared with the "self-controlled" animals, suggesting a role for these types of connection in forming the individual characteristics of higher nervous activity. The identical incidences of interneuron interactions in the lateral nucleus of the hypothalamus in cats with different individual preferences suggest that local networks in this formation are not involved in analyzing reinforcement quality.