Nicotine modifies the activity of ventral tegmental area dopaminergic neurons and hippocampal GABAergic neurons.
While trying to mimic the dose and time course of nicotine as it is obtained by a smoker, we found the following results. The initial arrival of even a low concentration of nicotine increased the firing rate of dopaminergic neurons from the ventral tegmental area (VTA) and increased the spontaneous vesicular release of GABA from hippocampal neurons. Longer exposure to nicotine caused variable, but dramatic, desensitization of nicotinic receptors and diminished the effects of nicotine. The addictive properties of nicotine as well as its diverse effects on cognitive function could be mediated through differences in activation and desensitization of nicotinic receptors in various areas of the brain.
Fisher
J L
JL
Division of Neuroscience, Baylor College of Medicine, Houston, Texas 77030-3498, USA.
Pidoplichko
V I
VI
Dani
J A
JA
D000818:Animals; D002478:Cells, Cultured; D004298:Dopamine / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D009474:Neurons / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017557:Ventral Tegmental Area / Q000166:cytology / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D005680:gamma-Aminobutyric Acid; D009538:Nicotine; D004298:Dopamine