Yao S T, Barden J A, Finkelstein D I, Bennett M R, Lawrence A J
Department of Pharmacology, Monash University, Clayton, Victoria 3168, Australia.
J Comp Neurol. 2000 Nov 27;427(4):485-507.
The present study investigated the topographical distribution of P2X(1)-P2X(6) receptor subtypes in the rat and common marmoset hindbrain by immunohistochemistry. In addition, double-labeling immunofluorescence was used to determine the extent of colocalization between catecholamine cell groups and the various P2X receptors. The data demonstrate a widespread distribution pattern for all six P2X receptors throughout both the rat hindbrain and the marmoset hindbrain, although distinctions between species, brain nuclei, and P2X receptor subtypes exist. In rat, dense staining for the P2X receptors was found in the nucleus of the solitary tract (NTS), medial vestibular nucleus, and medial and lateral parabrachial nuclei. Moderate staining was observed in the hypoglossal nucleus, cuneate nucleus, inferior olive, prepositus hypoglossi, rostral ventrolateral medulla (RVLM), and locus coeruleus. Staining was also observed in the gracile nucleus, the mesencephalic trigeminal nucleus, and the central pontine gray. In marmoset, prominent P2X receptor-like immunoreactivity occurred in the NTS, medial cuneate nucleus, prepositus hypoglossi, and medial vestibular nucleus. Moderate staining was observed in the area postrema, dorsal motor nucleus of the vagus, lateral cuneate, lateral reticular, spinal trigeminal nucleus, RVLM, and inferior olive. Immunofluorescent double labeling of tyrosine hydroxylase (TH)-containing cells revealed that all subtypes of P2X receptors show some degree of colocalization with TH. The highest proportion of TH and P2X receptor double labeling was in the A5 region (with the P2X(2) subunit), whereas the lowest proportion of double-labeled cells occurred in the C2 region of the NTS for the P2X(5) subunit. These findings support a role for extracellular adenosine 5'-triphosphate in fast synaptic neurotransmission within the brainstem.
本研究通过免疫组织化学方法，对大鼠和普通狨猴后脑P2X(1)-P2X(6)受体亚型的拓扑分布进行了研究。此外，采用双标免疫荧光法确定儿茶酚胺细胞群与各种P2X受体之间的共定位程度。数据表明，尽管在物种、脑核和P2X受体亚型之间存在差异，但所有六种P2X受体在大鼠后脑和狨猴后脑均呈现广泛的分布模式。在大鼠中，在孤束核（NTS）、内侧前庭核以及内侧和外侧臂旁核中发现P2X受体有密集染色。在舌下神经核、楔束核、下橄榄核、舌下前置核、延髓头端腹外侧区（RVLM）和蓝斑中观察到中度染色。在薄束核、中脑三叉神经核和脑桥中央灰质中也观察到染色。在狨猴中，NTS、内侧楔束核、舌下前置核和内侧前庭核中出现明显的P2X受体样免疫反应。在最后区、迷走神经背运动核、外侧楔束核、外侧网状核、三叉神经脊束核、RVLM和下橄榄核中观察到中度染色。对含酪氨酸羟化酶（TH）细胞的免疫荧光双标显示，所有P2X受体亚型均与TH有一定程度的共定位。TH和P2X受体双标的最高比例出现在A5区（含P2X(2)亚基），而双标细胞比例最低的是NTS的C2区中的P2X(5)亚基。这些发现支持细胞外三磷酸腺苷5'-三磷酸在脑干内快速突触神经传递中发挥作用。
