Excitatory 5-HT2-mediated effects on rostral ventrolateral medullary neurones in rats.
Iontophoretic application of the 5-HT2 receptor agonist alpha-methyl-5-HT excited 41 neurones in the rostral ventrolateral medulla, including a population of barosensitive cells. At high ejecting currents (greater than 2-3 x threshold) the excitation was replaced by an inhibition. The excitatory responses evoked by low doses of alpha-methyl-5-HT were reduced during iontophoretic application of ketanserin (2-5 nA) in 8/9 cells. alpha-Methyl-5-HT inhibited ongoing activity of a further 28 cells. The inhibitions were not blocked by ketanserin (n = 3). We suggest that alpha-methyl-5-HT exerts an excitatory 5-HT2-mediated effect on neurones in the rostral ventrolateral medulla.
Wang
W H
WH
Department of Physiology, The Medical School, Birmingham, UK.
Lovick
T A
TA
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D007478:Iontophoresis; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; C042390:alpha-methylserotonin; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin