LONG-TERM KINDLING AND INTERICTAL EMOTIONALITY IN RATS - EFFECT OF STIMULATION SITE

Long-term amygdala kindling in rats produces increases in emotionality (Kalynchuk et al., Biol. Psychiatry, 41 (1997) 438-451). The present experiment was conducted to investigate whether this hyperemotionality is specific to amygdala kindling or whether it can be produced by kin dling other structures. Rats received 99 convulsive or sham stimulatio ns of either the amygdala, the hippocampus, or the caudate nucleus. On e day after the stimulation phase, each rat's open-field activity and resistance to capture were assessed; the following day, each rat was t ested on an elevated plus maze. The site of stimulation had a signific ant effect on the results of each of these tests. The amygdala-kindled and hippocampal-kindled rats explored less in the open field, were mo re resistant to capture from the open field, and engaged in a greater percentage of open-arm activity in the elevated plus maze than did the caudate-kindled rats or the sham-stimulated controls. The caudate-kin dled rats were more active in the open field than their sham-stimulate d controls, but they did not significantly differ from them in terms o f the other measures. These results suggest that kindling-induced emot ionality is produced by limbic kindling but not nonlimbic kindling. (C ) 1998 Elsevier Science B.V.