Aims

To support the free and open dissemination of research findings and information on alcoholism and alcohol-related problems. To encourage open access to peer-reviewed articles free for all to view.

For full versions of posted research articles readers are encouraged to email requests for "electronic reprints" (text file, PDF files, FAX copies) to the corresponding or lead author, who is highlighted in the posting.

___________________________________________

Friday, January 25, 2013

Social Deprivation Enhances VTA Synaptic Plasticity and Drug-Induced Contextual Learning


Drug addiction is driven, in part, by powerful drug-related memories. Deficits in social life, particularly during adolescence, increase addiction vulnerability. Social isolation in rodents has been used extensively to model the effects of deficient social experience, yet its impact on learning and memory processes underlying addiction remains elusive. 

Here, we show that social isolation of rats during a critical period of adolescence (postnatal days 2142) enhances long-term potentiation of NMDA receptor (NMDAR)-mediated glutamatergic transmission in the ventral tegmental area (VTA). This enhancement, which is caused by an increase in metabotropic glutamate receptor-dependent Ca2+ signaling, cannot be reversed by subsequent resocialization.

 Notably, memories of amphetamine- and ethanol-paired contextual stimuli are acquired faster and, once acquired, amphetamine-associated contextual memory is more resistant to extinction in socially isolated rats. 

 We propose that NMDAR plasticity in the VTA may represent a neural substrate by which early life deficits in social experience increase addiction vulnerability.
Read Full Abstract

 Request Reprint E-Mail:  morikawa@utexas.edu
at