title: Time-dependent effects of intrahypothalamic injection of vasoactive intestinal peptide on spontaneous motor activity in rats.
abstract: In male Wistar rats, microinjection cannulae were stereotaxically implanted in the ventromedial and paraventricular hypothalamic nuclei. After control recordings of spontaneous motor activity for 4-6 days, vasoactive intestinal peptide (VIP) was injected in a dose of 1.0 microgram and a volume of 2.0 microliters into these nuclei at 1100 or 1900 h, and the activity during the 3-h period following was compared with that on the control days in individual animals. VIP injection produced an increase when injected at 1100 h, and a decrease when injected at 1900 h. Thus, a time-dependent fluctuation in the VIP effect on the hypothalamic neuronal activity was suggested.
authors.affiliation: Department of Physiology, Yokohama City University School of Medicine, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Hashimoto
authors.forename: C
authors.initials: C
authors.lastname: Praputpittaya
authors.forename: F
authors.initials: F
authors.lastname: Kimura
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D014660:Vasoactive Intestinal Peptide / Q000008:administration & dosage / Q000494:pharmacology*; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects*
chemical_list: D014660:Vasoactive Intestinal Peptide