IMMUNOHISTOCHEMICAL LOCALIZATION OF GUANINE NUCLEOTIDE BINDING REGULATORY PROTEIN IN BRAIN AND SPINAL CORD OF RAT / 解剖学报

ABSTRACT

The subunit ?_0 of guanine nucleotide- binding protein, in the areas of rat brain and spinal cord was localized by immunohistochemical methods. It was found that in the rat brain, specific ?_0-like immunoreactivity(?_0-Li) displayed regional heterogeneity, a high density of ?_0-Li revealed in neuropil, and somatic membranes as well as the neuronal processes.Most intense ?_0-Li can be seen in substantia nigra(pars reticulata), interpcduncular nucleus, habenulo-interpeduncular tract, strata oriens and radiatum of the hippocampus, and substantia gelatinosa of the spinal cord. There are also areas of moderate staining ie the molecular layer of cerebral and cerebellar cortex, habenula, caudate-putamen complexes, the midline nuclei of thalamus and hypothalamus, periaqueductal grey, grey layers of superior colliculus, the olivo-cerebellar tract and the spinal tract of the trigeminal nerve as well. By contrast, the immunoreactvity of ?_0 in septal nuclei, globus pallidus, red nucleus, and the regions adjacent canalis centralis of the spinal cord showed much weaker. In addition, on the membranes and the processes of the neuronal cell bodies in the periaqueductal grey, substantia nigra, reticular formation, medial geniculate body and the nucleus of the trapezoid body were ?_0-Li positive.The results of AChE staining revealed that the AChE-positivc nerve terminals was coinsident with the presence of ?_0-Li in the following regions. For instance the molecular layer of cerebral cortex, hippocampus, spinal tract of the trigminal nerve, and substantia gelatinosa of the spinal cord, where both the ?_0-Li and the AChE activity were positive. It is suggested that ?_0 subunit of Go-protein in brain might play roles in membrane signal transduction, and might have some relationship with cholinergic nerve.