Alterations of rat corticostriatal synaptic plasticity after chronic ethanol exposure and withdrawal.
BACKGROUND
The purpose of this study was to investigate the effects of chronic ethanol exposure (CEE) and withdrawal on corticostriatal plasticity in rats.


METHODS
We established an animal model of alcoholism using the method of Turchan et al. (1999). A synaptic model of long-term memory (long-term depression, LTD) was used as an index and the striatum, which is related to habit learning, was selected as a target region in the present study. The effects of CEE and withdrawal on the LTD were studied in striatal slices of ethanol-dependent rats using the extracellular recording method.


RESULTS
A stable LTD can be induced after high-frequency stimulation (HFS) in the slices of control rats. Chronic ethanol exposure and withdrawal suppressed the induction of corticostriatal LTD to different extents, with the strongest suppressive effects on LTD occurring in the slices of rats exposed to ethanol for 10 days and in those withdrawn from ethanol for 1 day. Notably, 3 days of withdrawal resulted in the shift of corticostriatal synaptic plasticity from LTD to long-term potentiation, and the peak latencies of the population spikes were obviously shortened compared with those of control rats. After 7 days of withdrawal, ethanol's effects tended to disappear.


CONCLUSIONS
These results suggest that the alterations of corticostriatal synaptic plasticity produced by CEE and withdrawal may play a prominent role in alcohol abuse and alcoholism.
Xia
Jian Xun
JX
Department of Physiology, Nanjing Medical University, Nanjing, China.
Li
Jing
J
Zhou
Rong
R
Zhang
Xiao Hu
XH
Ge
Yin Bing
YB
Ru Yuan
Xiao
X
D000437:Alcoholism / Q000503:physiopathology*; D000818:Animals; D001522:Behavior, Animal; D002540:Cerebral Cortex / Q000503:physiopathology*; D003342:Corpus Striatum / Q000503:physiopathology*; D000431:Ethanol / Q000008:administration & dosage* / Q000097:blood; D005260:Female; D006184:Habits; D007858:Learning; D017774:Long-Term Potentiation / Q000187:drug effects; D036881:Long-Term Synaptic Depression / Q000187:drug effects; D008297:Male; D008568:Memory; D009473:Neuronal Plasticity / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology*
D000431:Ethanol