ABSTRACT
For a number of years our research has been devoted to an analysis of the contribution of the mammalian amygdala to aversive conditioning processes. To analyze the contribution of this complex structure, comprised of a number of distinctly different nuclei lying deep in the temporal lobe, we adopted a wellcharacterized model response and conditioning paradigm; the conditioned decclerative heart rate (bradycardiac) response in the rabbit, a response which develops during Pavlovian aversive conditioning procedures. Our own results, as well as those of others, have led to our working hypothesis that the amygdaloid central nucleus (ACe) is an essential component of a forebrain-brainstem circuit which contributes, at least in part, to the motoric expression of the bradycardiac response. This function is presumably mediated via widespread projections from the nucleus and other structures with which it is associated to brainstem cardiomotor regions.
