Direct identification of individual vasopressin-containing nerve terminals of the rat neurohypophysis after 'whole-cell' patch-clamp recordings.

The membrane currents in rat neurophypophysial nerve terminals, which contain either vasopressin or oxytocin, have been previously recorded using the 'whole-cell' patch-clamp technique. Interpretation of the electrophysiological data would be significantly strengthened by the ability to correlate them with knowledge of the peptide contents of the terminals being studied. Here, a novel method for detection of the peptide hormone, arginine vasopressin, in those individual isolated terminals is described. The unique aspect of this procedure is that the contents of the terminal are aspirated into the recording electrode after 'whole-cell' patch-clamp recording, and then a highly sensitive dot immunobinding assay allows identification of the peptide contents in the terminals.