Fig. 5.

Chronic nicotine effects on non-opioid family neuropeptides. a, peptides derived from granin or granin-like precursors and from protachykinin; b, peptides derived from the precursors cholecystokinin, neurotensin/neuromedin N, vasoactive intestinal peptide, somatostatin, cerebellin-1, and pro-neuropeptide Y. Bars indicate the mean relative changes (%) of neurochemicals following chronic nicotine treatment. Error bars indicate variability of the difference between sample means (standard error). Asterisk denotes statistical significance (p < 0.05).