Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Chronic nicotine effects on opioid family neuropeptides. Bars indicate the mean relative changes (%) of peptides following chronic nicotine treatment. Error bars indicate variability of the difference between sample means (standard error). Asterisk denotes statistical significance (p < 0.05).
