Effects of chronic nicotine and pilocarpine administration on neocortical neuronal density and [3H]GABA uptake in nucleus basalis lesioned rats.
We investigated the possible long-term neuroprotective roles of (-)nicotine and muscarinic agonist, pilocarpine, in the neocortices of rats receiving bilateral nucleus basalis lesions. Ibotenic acid-lesioned animals eventually displayed a 15-20% reduction in the density of neocortical Nissl staining neurons in layers II, III and VI, as well as a 27% loss in high-affinity GABA uptake 8 months post-lesioning. Deficits were not observed at earlier intervals. (-)Nicotine (0.2 mg/kg, i.p.) or (-)nicotine plus pilocarpine (1 mg/kg, i.p.) attenuated these losses when administered once daily to rats from 5-8 months post-lesioning. Pilocarpine alone had no protective effect on neuronal density or GABA uptake. These results suggest that nicotine receptor activation may counteract neocortical neuronal loss/atrophy following loss of ascending basal forebrain neurons.
Sjak-Shie
N N
NN
Washington University School of Medicine, St. Louis, MO.
Meyer
E M
EM
D000818:Animals; D002452:Cell Count / Q000187:drug effects; D002540:Cerebral Cortex / Q000473:pathology*; D007051:Ibotenic Acid / Q000494:pharmacology; D009474:Neurons / Q000473:pathology*; D009538:Nicotine / Q000494:pharmacology*; D010862:Pilocarpine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013237:Stereoisomerism; D013377:Substantia Innominata / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D014316:Tritium; D005680:gamma-Aminobutyric Acid / Q000493:pharmacokinetics*
D010862:Pilocarpine; D014316:Tritium; D007051:Ibotenic Acid; D005680:gamma-Aminobutyric Acid; D009538:Nicotine