Effect of vasopressin, oxytocin and peptides derived from these hormones on field potential induced in lateral septum of rats by stimulation of the fimbria fornix

Abstract

Superfusion of the dorsal surface of the septum with artificial cerebrospinal fluid containing 10 −10 M [Arg 8]-vasopressin (VP) significantly increased the negative (N) wave in field potentials (FPs) elicited in the lateral septum (LS) of rats by stimulation of the fimbria-fornix. A similar increase in the FPs negativity was also observed following superfusion of the septum with [pGlu 4, Cyt 6] VP(4–9), [pGlu 4, Cyt 6] VP(4–8), [Cyt 6] VP(5–9), desglycinamide 9-VP and 1-deamino, 8-D-arginine-VP. However, for obtaining the effect with these peptides 10 3–4 times higher concentrations had to be used. Superfusion of the septum with 10 −8 M oxytocin (OX) elicited nearly the same N-wave increase as the 10 −8 M VP septal superfusion. The 10 −10 M concentration of OX as well as 10 −7 M [pGlu 4, Cyt 6] OX(4–9) and [pGlu 4, Cyt 6] OX(4–8) had little effect on the FPs negativity. The significance of these findings for the elucidation of the VP function in the LS is discussed.