LOCALIZATION OF GABAB RECEPTOR 1 SUBTYPE IN THE RAT NERVOUS SYSTEM

Objective To observe the distribution of GABAB receptor subtype 1 (GABABR1 ) in the rat nervous system. Method Immunocytochemical staining technique by using specific antibody against GABABR1 was used. Results Intensely and densely stained GABABR1-like immunoreactive neurons were observed in the V layer of cerebral cortex. islands of Calleja, caudate putamen, septohippocampal nucleus, hippocampus, basolateral amygdaloid nucleus, medial habenular nucleus, anterodorsal thalamic nucleus, mediodorsal thalamic nucleus, dorsal lateral geniculate nucleus. preoptic nuclei, supraoptic nucleus, lateral magnocellular part of paraven- tricular nucleus, anterior commisural nucleus, median eminence, arcuate nucleus, pars compacta of substantia nigra, ventral tegmental area, interpeduncular nucleus, Edinger-Westphal nucleus, mesencephalic trigeminal nucleus, locus coeruleus, nucleus of the trapezoid they, superficial layers of the caudalis subnucleus of the spinal trigeminal nucleus, dorsal motor nucleus of vagus, Purkinje cell layer of cerebellar cortex, laminae Ⅰ- Ⅲ, Ⅸ and X of spinal gray matter, lateral spinal nucleus, Onuf's nucleus and spinal dorsal root ganglion. Specially, in the cholinergic and monoaminergic nuclei of the brain. Conclusion These results indicate that GABABR1-like im- munoreactive structures are widely located in the rat brain. GABA might exert its principal inhibitory effects through these GABABR.