Neurochemical Effects of Nicotine on Albino Rat’s Brain

Background: In the recent era, smoking has become fashionable. Seventy percent of the Indian population is continuously being exposed to smoking. Cigarette smoking produces various quantities of nicotine that is readily absorbed by the physiological system of smokers.

Objectives: Adolescence is the period in which smokers typically begin their nicotine addiction. To date, no attempt has been made to estimate changes in cholinergic and DA-D2 receptors (Dopaminergic D2 receptors) following nicotine administration, although literature review has revealed available publications regarding changes in dopamine concentration following nicotine. Hence the present experiment was conducted to study the alteration of cholinergic and DA-D2 receptors in hippocampus and corpus striatum respectively following nicotine exposure by using neurochemical receptor binding techniques.

Materials and Methods: In the present study an experiment was done on male albino rats. Nicotine was administered for eight weeks orally via a cannula, using dose rate (5 mg/d, 10 mg/d). The results were compared with control adult rats, given vehicle in an identical manner. After exposure, we assessed [3H] Quinuclidinyl Benzilate as a specific ligand for cholinergic receptors in the hippocampus and DA-D2 receptors binding in corpus striatum using [3H] Spiperone as a specific ligand for DA-D2 receptor.

Results: Chronic nicotine treatment induced the up-regulation of cholinergic receptors in the hippocampus and down-regulation of DA-D2 receptors in the striatum.

Conclusions: Such knowledge is important for understanding nicotine dependence and the consequences of nicotine administration for the treatment of neurological disorders. These effects may underlie long-term behavioral changes associated with adolescent nicotine exposure.