Effect of acute and repeated nicotine administration on the electrical activity of the lateral habenular neurons in rats

Abstract

Compelling evidence has shown a pivotal role for dopaminergic function in the addiction to drugs of abuse like nicotine. Nicotinic acetylcholine receptors (nAChRs) are expressed throughout the CNS and can influence different brain areas and functions. Nicotine, acting through these receptors, can affect multiple neurotransmitter systems in the brain inducing neuroadaptations that may account for the observed alterations in brain reward systems involved in the addiction process and withdrawal symptoms. Recently, the Lateral Habenula (LHb) has attracted a great deal of attention as another target for nicotine in the brain because of its role in regulating dopamine (DA) system neuronal activity. In particular, it has been suggested that the symptoms associated with nicotine withdrawal might be associated with an altered output from the LHb induced by continuous exposure to nicotine. Although the presence of nAChRs in the LHb has been shown, the extent to which the LHb may contribute to the neurobiological action of nicotine still needs to be fully addressed. Here, we investigated the effects of both acute and chronic exposure to nicotine on LHb neuronal activity and nAChRs expression at the level of this area.