Expression of the cholecystokinin gene in rat hippocampal interneurons is independent of extrinsic input.

In the present study we have used slice cultures of hippocampus and in situ hybridization techniques in order to study the ability of hippocampal neurons to synthesize CCK mRNA in the absence of extrinsic afferents. Our results show that very similar types of hippocampal neurons express CCK mRNA in culture as in situ. We conclude that the expression of the CCK gene in hippocampal neurons is not dependent on extrinsic afferent input.