Specific binding of 125I-hippocampal cholinergic neurostimulating peptide (HCNP) to rat brain membranes: characterization and regional distribution.

An undecapeptide-hippocampal cholinergic neurostimulating peptide (HCNP), originally purified from young rat hippocampus, enhances cholinergic phenotype development in the medial septal nucleus in vitro. To survey and characterize the HCNP receptor within the central nervous system, we used iodinated HCNP as a labeled ligand. In preliminary experiments, [125I]HCNP binding was highest in the crude P2 membrane fraction, so all subsequent experiments were performed using this fraction.