Effects of neuropeptide Y on appetitive and consummatory behaviors associated with alcohol drinking in wistar rats with a history of ethanol exposure.
BACKGROUND
Neuropeptide Y (NPY) reduces ethanol intake under free access conditions in Wistar rats with a history of prolonged ethanol vapor exposure. The current study was designed to determine whether NPY differentially alters ethanol-associated appetitive behavior (i.e., lever pressing) or ethanol consumption in Wistar rats with a history of ethanol vapor exposure.


METHODS
Wistar rats were first trained to self-administer 10% ethanol in a paradigm that provided 25 min of free access to 10% ethanol after completing a 20-lever press response requirement (i.e., an RR20 schedule). After stable level lever pressing was established, operant sessions were suspended during a 9-week period of ethanol vapor exposure. Self-administration sessions were then reinstituted, and a fixed time (FT) schedule of 10% ethanol access was used to assess the effects of ethanol exposure and NPY on lever pressing and drinking behavior. Under the FT schedule, the maximum number of lever presses emitted within 10 min was assessed before providing access to 10% ethanol.


RESULTS
Ethanol vapor exposure did not alter patterns of lever pressing under the RR20 schedule, but lever presses emitted under the FT schedule were reduced after ethanol vapor exposure. Ethanol intake was significantly increased after ethanol vapor exposure. NPY significantly reduced ethanol intake but did not significantly reduce lever pressing under the FT schedule.


CONCLUSIONS
Taken together, these data suggest that chronic ethanol exposure increases ethanol intake without clearly enhancing its reinforcing value. Furthermore, NPY has a greater impact on the consummatory factors mediating ethanol intake than appetitive factors mediating ethanol seeking.
Thorsell
Annika
A
The Scripps Research Institute, Department of Neuropharmacology, La Jolla, California 92037, USA.
Slawecki
Craig J
CJ
Ehlers
Cindy L
CL
D000280:Administration, Inhalation; D000428:Alcohol Drinking / Q000523:psychology*; D000818:Animals; D019167:Appetite Stimulants / Q000494:pharmacology*; D001070:Appetitive Behavior / Q000187:drug effects*; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects; D003259:Consummatory Behavior / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D009478:Neuropeptide Y / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012055:Reinforcement Schedule; D012646:Self Administration
D019167:Appetite Stimulants; D002492:Central Nervous System Depressants; D009478:Neuropeptide Y; D000431:Ethanol