NEURONAL SUBSTRATE OF ELECTRICALLY-INDUCED GROOMING IN THE PVH OF THERAT - INVOLVEMENT OF OXYTOCINERGIC SYSTEMS

Electrical stimulation of the paraventricular (PVH) and adjacent hypot halamic area evokes self-grooming behaviour. Current intensity thresho lds for grooming can be obtained depending on the exact localization o f the electrode site. Sites localized at greater distance of the cente r of the grooming area evoke grooming at greater latencies and higher current intensity, or no grooming at all. Results are compared with in jections of neuroactive substances into the PVH from previous studies, which showed a similar site specificity for grooming. We found simila rity in the distribution of electrode sites in the paraventricular and anterior hypothalamic areas at which grooming is induced, and hypotha lamic immunoreactive oxytocinergic neurons and fibres. In addition, we reported earlier that oxytocin infusions into the PVH in resting anim als induce grooming, in contrast to other grooming-related peptides, s uch as alpha-melanocyte-stimulating hormone. We hypothesize that elect rical stimulation may induce grooming by activation of oxytocinergic s ystems originating from the PVH.