Nicotinic receptor expression following nicotine exposure via maternal milk.

Studies have shown nicotine is excreted into maternal milk, so that suckling offspring would be a target of the drug during the pre-weaning period. Since nicotine exposure leads to an upregulation of neuronal nicotinic receptors, this study examines the hypothesis that nicotine delivered via maternal milk is capable of altering neuronal nicotinic receptor regulation in the drug-exposed rat pups. The present study showed that postnatal nicotine exposure via maternal milk was sufficient to induce an upregulation in brain nicotinic receptors similar to that seen in adults that smoke. Such exposure may result in altered neuronal development and synaptic activity and structure, potentially leading to long-term behavioral, learning, and memory deficits.