[Effects of 5-HT on activity of arcuate neurons of rat hypothalamic slices].
Extracellular recordings were made from 176 spontaneous discharging units in the arcuate nucleus of rat hypothalamic slices. Depending on the patterns of discharge, the units were divided into three types; slow irregular (76%), fast continuous (26.5%) and phasic units (6.3%). The effect of 5-HT on the different types of units were observed. The results indicated that most of neurons were inhibited by 5-HT, and only a small portion of the cells showed excitation and a few of the slow irregular units showed "excitation after inhibition". With 5-HT 10(-6) mol/L we found that 12 units inhibited by 5-HT could not be reversed by CHD, while the 4 inhibited units could be partly or completely reversed by MSG. 4 of the 7 neurons inhibited by 5-HT were partly blocked by Pindobind-5-HT1A but not for the remaining 3 neurons. The results suggest that the inhibitory effect of 5-HT on arcuate neurons may be mediated by 5-HT1 receptor, while some by 5-HT1A receptor.
Tao
P
P
Department of Brain and Nerve, Xian Medical University.
Mei
J
J
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000502:physiology*; D000081005:Cyclohexane Monoterpenes; D003533:Cyproheptadine / Q000494:pharmacology; D003864:Depression, Chemical; D004594:Electrophysiology; D005260:Female; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D009474:Neurons / Q000502:physiology; D010869:Pindolol / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology
D000081005:Cyclohexane Monoterpenes; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C084712:pindobind; D003533:Cyproheptadine; D012701:Serotonin; D010869:Pindolol; D008784:Methysergide