RT Journal Article
SR Electronic
T1 Nicotine Self-Administration Impairs Hippocampal Plasticity
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3656
OP 3662
DO 10.1523/JNEUROSCI.22-09-03656.2002
VO 22
IS 9
A1 Djoher Nora Abrous
A1 Walter Adriani
A1 Marie-Françoise Montaron
A1 Catherine Aurousseau
A1 Geneviève Rougon
A1 Michel Le Moal
A1 Pier Vincenzo Piazza
YR 2002
UL http://www.jneurosci.org/content/22/9/3656.abstract
AB Nicotine, the neuroactive compound responsible for tobacco addiction, is primarily believed to have beneficial effects on the adult brain. However, in heavy smokers, abstinence from nicotine is accompanied by cognitive impairments that suggest adverse effects of nicotine on brain plasticity. For this reason, we studied changes in plasticity-related processes in the dentate gyrus (DG) of the hippocampal formation of animals trained to self-administer nicotine. The DG was chosen because it undergoes profound plastic rearrangements, many of which have been related to memory and learning performances. In this region, we examined the expression of the polysialylated (PSA) forms of neural cell adhesion molecule (NCAM), PSA-NCAM, neurogenesis, and cell death by measuring the number of pyknotic cells. It was found that nicotine self-administration profoundly decreased, in a dose-dependent manner, the expression of PSA-NCAM in the DG; a significant effect was observed at all the doses tested (0.02, 0.04, and 0.08 mg/kg per infusion). Neurogenesis was also decreased in the DG, but a significant effect was observed only for the two highest doses of nicotine. Finally, the same doses that decreased neurogenesis also increased cell death. These results raise an important additional concern for the health consequences of nicotine abuse and open new insight on the possible neural mechanisms of tobacco addiction.