RU 24969-produced adipsia and hyperlocomotion: differential role of 5HT 1A and 5HT 1B receptor mechanisms.
RU 24969 is a widely used, but non-selective, 5-HT1B/1A agonist that decreases fluid consumption and increases forward locomotion. The mechanism underlying these behavioural responses is not, however, well understood. Accordingly, effects of the selective 5-HT1A and 5-HT1B antagonists, WAY 100635, and GR 127935, respectively, on these two responses to RU 24969 were determined. RU 24969 (0.03-3.0mg/kg, s.c.) dose-dependently decreased water consumption in water deprived rats. This effect was attenuated by GR 127935 (3.0mg/kg), but not by WAY 100635 (1.0mg/kg). RU 24969 (0.3-3.0mg/kg) dose-dependently increased forward locomotion but a higher dose was required to produce this response than the adipsic response. The increased locomotor response was attenuated by WAY 100635 (1.0mg/kg), but not GR 127935 (3.0mg/kg). These results suggest that RU 24969-induced adipsia is mediated by 5-HT1B mechanisms, while RU 24969-induced hyperlocomotion is mediated by 5-HT1A mechanisms.
School of Psychology, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand.
Dane
D
Aronsen
School of Psychology, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand.
Jeremy
J
Webster
School of Psychology, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand. Electronic address: Susan.Schenk@vuw.ac.nz.
Susan
S
Schenk
D000818:Animals; D004327:Drinking Behavior / Q000187:drug effects*; D007211:Indoles / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects*; D044302:Receptor, Serotonin, 5-HT1B / Q000187:drug effects*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D007211:Indoles; D044302:Receptor, Serotonin, 5-HT1B; D017366:Serotonin Receptor Agonists; D044282:Receptor, Serotonin, 5-HT1A; C025145:5-methoxy 3-(1,2,3,6-tetrahydro-4-pyridinyl)1H indole
Adipsia; Hyperlocomotion; RU 24969; Serotonin(1A); Serotonin(1B)