Re: Nicotine addiction?
Whilst not testing addiction or withdrawal, paragraphs in the results of that study and some of those linked suggest to me that nicotine is addictive (in rats at least);
"Consistent with previous reports (O'Dell et al. 2007; Valentine et al. 1997), in this study, most nicotine injections were obtained during the dark phase of the light cycle when rats are most active. However, with very prolonged access to nicotine SA (e.g., 40 days), nicotine intake was reported to be less circadian, and the difference in nicotine intake between dark and light phases diminished"
Or, just a stray stupid thought, it could indicate that rats, like people, are more likely to ingest nicotine when awake?
And that as it is supposedly a stimulant (or can have that effect on some people), over longer periods with unnatural substances in unnatural settings, perhaps their sleep is more erratic, hence the 40 day results?
Correlation/causation 'n all that..