Peripheral nicotine administration increases rubral firing rates in the urethane-anesthetized rat.
The presence of cholinergic input to the red nucleus (RN) in the cat is demonstrated by choline acetyltransferase (ChAT) staining; however, it is unclear what effect this cholinergic input has on neurons of the RN. Further, the presence of cholinergic neurons in the rat RN has been the subject of controversy. The present study examined the effects of intravenous injections of S(-)-nicotine tartrate (62.5-250 micrograms/kg) on the firing rate of rubral neurons. Dose-dependent increases in firing rates were observed which were blocked by pre-treatment with the nicotinic antagonist, mecamylamine hydrochloride. Smaller consistent increases were found after pretreatment with 62.5 micrograms/kg or 125 micrograms/kg doses of nicotine than were observed following the initial administration, suggesting a desensitizing response typical of nicotinic receptors.
Kinney
G G
GG
Astra Arcus USA, Department of Biology, Rochester, NY 14602, USA.
D000758:Anesthesia; D000818:Animals; D003847:Deoxyglucose; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005947:Glucose / Q000378:metabolism; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects; D009538:Nicotine / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D051381:Rats; D012012:Red Nucleus / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D014520:Urethane
D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; D014520:Urethane; D008464:Mecamylamine; D009538:Nicotine; D003847:Deoxyglucose; D005947:Glucose