Direct osmotic stimulation of the hypothalamic paraventricular nucleus by microdialysis induces excessive grooming in the rat.
This study examined the effects of direct osmotic stimulation of the hypothalamic paraventricular nucleus (PVN) on grooming behavior of adult male rats. Animals chronically fitted with a microdialysis probe in the right PVN responded to dialysis with hypertonic (containing 1 M NaCl) artificial cerebrospinal fluid (aCSF) with grooming behavior (to approx. 500%, P < 0.01, ANOVA) and a significantly reduced time resting (to approx. 20%, P < 0.01, ANOVA), compared with controls which received either the same treatment in the right supraoptic nucleus or in which the PVN was dialyzed with isotonic (0.15 M NaCl) a CSF. These results indicate that direct osmotic stimulation of the PVN via microdialysis is able to trigger and to maintain excessive grooming activity in rats; the novel experimental approach used here provides the potential to investigate the involvement of endogenous, intracerebrally released substances in the grooming response.
Engelmann
M
M
Max Planck Institute of Psychiatry, Munich, Germany.
Wotjak
C T
CT
Landgraf
R
R
D000818:Animals; D006120:Grooming / Q000502:physiology*; D008297:Male; D017551:Microdialysis; D018377:Neurotransmitter Agents / Q000502:physiology; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013495:Supraoptic Nucleus / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000502:physiology*
D018377:Neurotransmitter Agents