The effects of dorsal and ventral noradrenergic system lesions with DSP-4 on emotional-defensive behavior and regional brain monoamines content in the cat.

As a result of selective lesions of dorsal (DB) and ventral (VB) noradrenergic system (DSP-4 i.c.) it was observed that these two systems are functionally differentiated and only DB participates in the regulation of post-carbachol emotional-defensive behavior in the cat. Following DB lesion an increase in emotional-defensive excitation occurred and HPLC analysis showed a significant reduction of NA concentration in the posterior hypothalamus, midbrain central gray matter and frontal cortex and decreased turnover of 5-HT in all "emotional brain areas" (hypothalamus, midbrain, amygdala, hippocampus) and frontal cortex. Following VB lesion there were no significant changes of post-carbachol defensive behavior and HPLC analysis showed a significant reduction of NA in the anterior and posterior hypothalamus, midbrain central gray matter and amygdala and an increased turnover of 5-HT in the posterior hypothalamus and midbrain central gray matter. The results obtained can be interpreted in relation to functional interactions between the NA and 5-HT systems.