Effect of amine on temperature-responsive neuron in slice preparation of rat brain stem.
Using slice preparations we investigated the effect of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) on thermoresponsive neurons in the hypothalamus, midbrain, and the medulla oblongata. NE inhibits the activities of most of the warm-responsive neurons (11 out of 13 neurons) but 5-HT activates the warm-responsive neurons (10 out of 11 neurons) in the hypothalamus. However, the direction of neuronal response of the midbrain was opposite of that in the hypothalamus when 5-HT was applied. In the medulla oblongata, 5-HT facilitates both warm- and cold-responsive neurons and NE facilitates or inhibits these neurons in equal proportions. Furthermore, the dose-response relationships were determined using slice preparations. In the hypothalamus and the midbrain, NE and 5-HT started to effect the warm-responsive neurons at the minimum concentration of 5 X 10(-6) M, whereas the maximum responses were obtained at the concentration of 5 X 10(-5) M. In the medulla oblongata, NE or 5-HT changed the activities of the warm-responsive neurons in the range of 5 X 10(-5) to 10(-3) M or 10(-6) to 10(-5) M, respectively. It is concluded that the thermoresponsive neurons respond to 5-HT and NE in different ways, at both various levels in the central nervous system and the applied concentration of amines.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001833:Body Temperature Regulation; D001933:Brain Stem / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D008636:Mesencephalon / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology*; D011903:Raphe Nuclei / Q000187:drug effects / Q000502:physiology; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*
D012701:Serotonin; D009638:Norepinephrine