Changes in ingestive behavior induced by intracranial injection of spermine

Effect of intracranial injection of spermine on feeding and drinking behavior was studied in rats. A significant and long-term suppression of feeding and drinking behavior appeared when 30 nmol/hemisphere of spermine was bilaterally injected into the lateral hypothalamic area, substantia nigra or ventral noradrenergic bundle. Micro-injected spermine into the medial amygdaloid nucleus produced a weak and short-time but significant suppression of ingestive behavior. On the other hand, a significant increase in feeding and drinking behavior was observed when spermine was injected into the ventromedial hypothalamic nucleus. These results suggest that spermine inhibits neuronal activity of all the brain regions studied here.