TY - JOUR
T1 - Central serotonergic lesions increase voluntary alcohol consumption in Sprague Dawley rats
T2 - Moderation by long-term ethanol administration
AU - Wang, Jia Yi
AU - Shum, Andrew Y.C.
AU - Lin, Tzu Chao
AU - Wang, Yun
PY - 1996
Y1 - 1996
N2 - The relationship between central serotonergic activities and voluntary alcohol consumption was studied in Sprague-Dawley rats, which normally have low alcohol preference. After initial screening for an evenly matched baseline alcohol preference, selective central serotonergic lesioning was induced by intracisternal injection of the serotonergic neurotoxin 5,7- dihydroxytryptamine (5,7-DHT). Control rata received injections of vehicle only. Both 5,7-DHT and vehicle-treated rata were further divided into two subgroups, which either had continued free access to ethanol (alcohol- drinking) or were deprived of it (alcohol-free). All rats were then tested again for alcohol preference. All rats were then killed, and the levels of monoamines in the brains were determined by high performance liquid chromatography with electrochemical detection. Behavioral results indicated that all 5,7-DHT-treated rats had significantly higher alcohol preference and consumption than the corresponding sham controls. Except in the cerebellum, the 5,7-DHT-treated rats had significantly lower levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in most brain regions compared with those in the corresponding sham controls. Treatment with 5,7-DHT also resulted in a decrease in serotonin turnover in all brain regions in the alcohol-free rats, except in the cerebellum. In alcohol-drinking rats, however, 5,7-DHT treatment only reduced serotonin turnover in the pons. The levels of norepinephrine and dopamine in several brain regions were not significantly different. Thus, it appeared that in the Sprague Dawley rats, 5,7-DHT treatment depleted 5-HT and 5-HIAA levels in most brain regions while increasing alcohol consumption. Chronic alcohol-drinking attenuated the increase in alcohol consumption associated with serotonergic lesions. Voluntary alcohol consumption seemed more associated with 5-HT turnover than with tissue 5-HT levels. Our data also suggested that tolerance to alcohol- induced hypothermia was primarily attributable to long-term alcohol drinking rather than serotonergic lesioning.
AB - The relationship between central serotonergic activities and voluntary alcohol consumption was studied in Sprague-Dawley rats, which normally have low alcohol preference. After initial screening for an evenly matched baseline alcohol preference, selective central serotonergic lesioning was induced by intracisternal injection of the serotonergic neurotoxin 5,7- dihydroxytryptamine (5,7-DHT). Control rata received injections of vehicle only. Both 5,7-DHT and vehicle-treated rata were further divided into two subgroups, which either had continued free access to ethanol (alcohol- drinking) or were deprived of it (alcohol-free). All rats were then tested again for alcohol preference. All rats were then killed, and the levels of monoamines in the brains were determined by high performance liquid chromatography with electrochemical detection. Behavioral results indicated that all 5,7-DHT-treated rats had significantly higher alcohol preference and consumption than the corresponding sham controls. Except in the cerebellum, the 5,7-DHT-treated rats had significantly lower levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in most brain regions compared with those in the corresponding sham controls. Treatment with 5,7-DHT also resulted in a decrease in serotonin turnover in all brain regions in the alcohol-free rats, except in the cerebellum. In alcohol-drinking rats, however, 5,7-DHT treatment only reduced serotonin turnover in the pons. The levels of norepinephrine and dopamine in several brain regions were not significantly different. Thus, it appeared that in the Sprague Dawley rats, 5,7-DHT treatment depleted 5-HT and 5-HIAA levels in most brain regions while increasing alcohol consumption. Chronic alcohol-drinking attenuated the increase in alcohol consumption associated with serotonergic lesions. Voluntary alcohol consumption seemed more associated with 5-HT turnover than with tissue 5-HT levels. Our data also suggested that tolerance to alcohol- induced hypothermia was primarily attributable to long-term alcohol drinking rather than serotonergic lesioning.
KW - 5,7-Dihydroxytryptamine
KW - Alcohol Consumption
KW - Serotonin
KW - Sprague Dawley Rat
KW - Tolerance
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U2 - 10.1111/j.1530-0277.1996.tb01120.x
DO - 10.1111/j.1530-0277.1996.tb01120.x
M3 - Article
C2 - 8904979
AN - SCOPUS:0029961315
SN - 0145-6008
VL - 20
SP - 1252
EP - 1259
JO - Alcoholism: Clinical and Experimental Research
JF - Alcoholism: Clinical and Experimental Research
IS - 7
ER -