Nicotine withdrawal in the rat: role of alpha7 nicotinic receptors in the ventral tegmental area.
Previous data show that nicotinic receptors in the ventral tegmental area are of importance for the nicotine withdrawal syndrome. Here we have investigated the specific role of alpha7 nicotinic receptors in the ventral tegmental area for the neurobiological and behavioral consequences of nicotine withdrawal. Rats were exposed to nicotine for 14 days via s.c. osmotic minipumps. Bilateral intrategmental injections of the selective alpha7 nicotinic receptor antagonist methyllycaconitine reduced locomotion in the nicotine-treated rats, but not in control animals. Unilateral intrategmental injection of methyllycaconitine reduced dopamine output in the ipsilateral nucleus accumbens of nicotine-treated rats, but not in controls. Our results indicate that alpha7 nicotinic receptors in the ventral tegmental area are involved in the nicotine withdrawal syndrome.
Nomikos
G G
GG
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Hildebrand
B E
BE
Panagis
G
G
Svensson
T H
TH
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D004298:Dopamine / Q000378:metabolism; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects; D009538:Nicotine / Q000009:adverse effects*; D018722:Nicotinic Agonists / Q000009:adverse effects*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000378:metabolism*; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000378:metabolism*; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579165:Chrna7 protein, rat; D018722:Nicotinic Agonists; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor; D015102:3,4-Dihydroxyphenylacetic Acid; D009538:Nicotine; D004298:Dopamine; D006719:Homovanillic Acid