[Expression of gamma-amino butyric acid and its receptor in the marginal division of rat striatum].

Objective: To investigate the expression of the inhibitory amino acid gamma-aminobutyric acid (GABA) and its receptor GABAR (B1) mRNA in the marginal division of rat striatum.

Methods: The expression of GABA and its receptor GABAR (B1) mRNA was studied by way of immunocytochemistry and molecular in situ hybridization method.

Results: Dense GABA-positive immunoreactive fibers and a few positive cells were found in the marginal division of the rat striatum, along with glutamic acid decarboxylase (GAD)-positive fibers and cell bodies. GABA- and GAD-positive cells and fibers were also seen in the cerebral cortex and hippocampus. Numerous cells positive of the expression of GABAR (B1) receptors mRNA were observed in the marginal division whereas only a few positive cells were found in the caudate putamen. GABAR (B1) receptor mRNA expression was also observed in some cells in the cerebral cortex and hippocampus.

Conclusion: The expression of GABA and its receptor in the marginal division of rat striatum indicates a regulatory mechanism of the marginal division of the striatum by GABA, suggesting that GABA can affect the learning and memory function of the marginal division through inhibiting the neurotransmitter release in the presynaptic terminal or modulating the other neurotransmitters.