Neurotransmitter modulation of VIP release from cat cerebral cortex.
The cortical release of vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) in vivo was examined by superfusion of the pial surface of the cerebral cortex of the cat. The modulation of cortical VIP release by several neurotransmitters [gamma-aminobutyric acid (GABA), opioids, norepinephrine, acetylcholine, and glutamate] normally present in the cerebral cortex was studied by administering respective agonists and antagonists for their receptors. Although GABA and opiate agonists did not influence the resting release of VIP-LI, GABA antagonists (picrotoxin and bicuculline) and opiate antagonists (naloxone and naltrexone) significantly elevated the resting release. The evoked release from cortex of VIP-LI (by electrical stimulation of the cortex or mesencephalic reticular formation) was suppressed by GABA and mu- but not delta-, kappa-, or sigma-opioid receptor agonists. Glutamate and kainic acid increased the resting release of VIP-LI from the cerebral cortex. Noradrenergic (alpha 2 but not alpha 1) displayed an inhibitory effect on the evoked release of cortical VIP-LI release. Resting VIP-LI release was enhanced by cholinergic agents (carbachol). The facilitatory effects of mesencephalic reticular formation stimulation on VIP-LI release were demonstrated by atropine. These observations suggest characteristic interactions reflecting the circuitry modulating the activity of cortical VIP-releasing neurons.
Wang
J Y
JY
Yaksh
T L
TL
Harty
G J
GJ
Go
V L
VL
D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D002415:Cats; D002540:Cerebral Cortex / Q000378:metabolism*; D004558:Electric Stimulation; D005260:Female; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000502:physiology; D018377:Neurotransmitter Agents / Q000494:pharmacology / Q000502:physiology*; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000502:physiology; D010277:Parasympathomimetics / Q000494:pharmacology; D011863:Radioimmunoassay; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D005971:Glutamates; D009292:Narcotic Antagonists; D009294:Narcotics; D018377:Neurotransmitter Agents; D010277:Parasympathomimetics; D014660:Vasoactive Intestinal Peptide; D018698:Glutamic Acid; D007608:Kainic Acid; D009638:Norepinephrine