Several neurotransmitters have been implicated in the effects of short-term nicotine administration and deprivation, including serotonin (5-HT; Benowitz, 2008). Serotonin is involved in the regulation of many brain functions, including sleep, cognition, sensory perception, motor activity, temperature regulation, mood, appetite, sexual behavior, and hormone secretion (Murphy et al., 2008). The diversity of the physiologic function of 5-HT is likely due to the fact that it orchestrates the activity and interaction of several other neurotransmission systems (Lesch & Mossner, 1998). Studies have shown that 5-HT function has broad developmental effects, promoting differentiation of serotonergic as well as glutaminergic neurons (Pezawas et al., 2005). Additionally, 5-HT levels are considered to be critical for the emotional development of the brain and can modify neural connections implicated in an increased risk for mood and anxiety-related disorders (Gross & Hen, 2004; Gaspar, Cases, & Maroteaux, 2003).
