Fallert M, Böhmer G, Dinse H R, Sommer T J, Bittner A
Arch Ital Biol. 1979 Jan;117(1):1-12.
Six putative neurotransmitters and the beta-receptor excitant isoproterenol were applied to bulbar respiratory neurons classified according to their burst discharge in the respiratory cycle and, for comparison, also to "unspecific" cells. With glycine inhibition occurred in I and prevailed in unspecific neurons. With GABA inhibition preponderated in I and E neurons. Glutamate excited E neurons. With dopamine inhibition prevailed in I and unspecific neurons. The majority of E neurons remained unaffected. With NE excitation occurred in EI and preponderated in I, IE, E and unspecific neurons, while some IE and E neurons were inhibited. The effects of isoproterenol did not allow any clear statement about receptor properties. In I units, however, activation was more frequent than inhibition. With 5-HT excitation prevailed in IE neurons. About half of the I cells remained unaffected and in the remainder inhibition preponderated over activation. This suggests the existence of two 5-HT-specific receptors in I and IE neurons. Comparison of the single effects revealed differences in the receptor properties of the various cell types. Results suggest that some cell types possess dopaminergic receptors and that these differ from NE-receptors, which have been found in all cell types. NE-receptor stimulation apparently can result in neuronal activation or inhibition.
将六种假定的神经递质和β受体激动剂异丙肾上腺素应用于根据呼吸周期中的爆发性放电分类的延髓呼吸神经元，并作为比较，也应用于“非特异性”细胞。使用甘氨酸时，I类神经元出现抑制，且在非特异性神经元中占主导。使用γ-氨基丁酸时，I类和E类神经元中抑制作用占优势。谷氨酸使E类神经元兴奋。使用多巴胺时，I类和非特异性神经元中抑制作用占主导。大多数E类神经元未受影响。使用去甲肾上腺素时，EI类神经元出现兴奋，且在I类、IE类、E类和非特异性神经元中占优势，而一些IE类和E类神经元受到抑制。异丙肾上腺素的作用无法对受体特性做出任何明确说明。然而，在I类单位中，激活比抑制更频繁。使用5-羟色胺时，IE类神经元中兴奋占优势。约一半的I类细胞未受影响，其余细胞中抑制作用超过激活作用。这表明在I类和IE类神经元中存在两种5-羟色胺特异性受体。对单一效应的比较揭示了各种细胞类型在受体特性上的差异。结果表明，某些细胞类型具有多巴胺能受体，且这些受体与在所有细胞类型中都发现的去甲肾上腺素受体不同。去甲肾上腺素受体刺激显然可导致神经元激活或抑制。
