THE EFFECTS OF SLEEP PROMOTING AGENTS ON BEHAVIORAL STATE IN THE OVINE FETUS

Fetal behavioural states, with similarities to adult sleep states, exi st in both the human and ovine fetus near term. The purpose of the pre sent study was to determine the effects of intracerebral administratio n of pharmacologic agents, known to affect sleep states in the adult, on fetal behavioural states and physiologic correlates using the chron ically catheterized ovine fetus near term. Each drug was infused into either the cisterna magna or lateral ventricle for 90 min in one of tw o doses. Carbachol (1.35 X 10(-5) and 4.25 x 10(-6) M) led to an incre ase in low-voltage ECOG, eye movement and FBM activities, while scopol amine (4.68 X 10(-4) and 1.56 X 10(-4) M) led to a decrease in low-vol tage ECOG and eye movement activity with an increase in high-voltage E COG activity. L-5-Hydroxytryptophan (5-HTP) (2.04 X 10(-3) and 6.81 X 10(-4) M) infusion led to an increase in FBM, while VIP (3.00 x 10(-7) and 1.00 X 10(-7) M) infusion had no effect on fetal behavioural stat e parameters. Study results indicate that fetal behavioural states can be altered pharmacologically and in a manner similar to that seen in the adult but with notable differences that may relate to species, dev elopmental or dose-response issues. (C) 1997 Elsevier Science B.V.