Galanin regulation of acetylcholine release and carbachol-stimulated phosphoinositide turnover in rat ventral hippocampus
Immunohistochemical analysis has shown that galanin (GAL) and choline acetyltransferase-like immunoreactivities coexist within cholinergic cell bodies in rat medial septal and diagonal band nuclei which innervate the hippocampal formation. However, the cholinergic cell bodies containing GAL project almost entirely to the ventral part of the hippocampus (see Melander et al., this volume). The greater presence of GAL immunoreactive fibers in this part of the hippocampus correlates well with the higher density of [125I]GAL binding sites in the ventral than in the dorsal part as determined by equilibrium binding studies and receptor autoradiography (Fisone et al., this volume). After transection of the septal and fimbrial afferents to the hippocampus, the density of the [125I] GAL binding sites is markedly reduced in the ventral hippocampus indicating that a large proportion of the putative GAL receptors are localized on the septal cholinergic afferents to this brain region.
KeywordsMuscarinic Receptor Dorsal Hippocampus Acetylcholine Release Kynurenic Acid Ventral Hippocampus
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