Rats were trained to self-stimulation for lateral hypothalamic medial forebrain bundle self-stimulation. When simultaneous ipsilateral amygdaloid stimulation accompanied each bar-press, there was an increase in response rate and a decrease in threshold for lateral hypothalamic self-stimulation. The same effect was observed after bilateral lesion of stria terminalis (Experiment 1). The increase in excitability of the lateral hypothalamic rewarding neurons in response to the contingent amygdala stimulation was also demonstrated by the findings that incentive shifts, indicated by positive and negative contrast effects, appeared when amygdala stimulation was started or interrupted, respectively (Experiment 2). On the basis of experimental data and the related literature it is assumed that the amygdala cannot represent a primary or basic reinforcing mechanism, but it has a definite role in the neural mechanism of central processes of higher level, whose control on the basic neuronal mechanism of reward may only be important in the organization of more complex forms of adaptive behavior.
- Contrast effects of incentive shifts
- Lateral hypothalamus
- Medial forebrain bundle
- Stria terminalis
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Behavioral Neuroscience