In vivo nicotine exposure in the zebra finch: A promising innovative animal model to use in neurodegenerative disorders related research

Nicotine improves cognitive enhancement and there are indications that neurodegenerative (age-related) cognitive disorders could be treated with nicotine-based drugs. The zebra finch is a well-recognized model to study cognitive functioning; hence this model could be used to study the effects of nicotine in neurodegenerative cognitive disorders. However, nicotine's in vivo physiological and behavioral effects have never been studied in the zebra finch. Here we present the first in vivo nicotine study in zebra finches. We evaluated the dose-response effects of nicotine on locomotor activity, song production, food intake and body weight. A liquid chromatography tandem mass spectrometry method was developed and validated for quantification of nicotine and cotinine in feces. The subcutaneous nicotine drug regiment (0.054-0.54 mg/kg) induced physiologically significant values of nicotine and cotinine. The mid (0.18 mg/kg) and high (0.54 mg/kg) dose of nicotine promoted the development and expression of a sensitized response of song production and locomotor activity. Food intake and body weight were not affected following nicotine exposure. In conclusion, the zebra finch can be used as an innovative animal model not only in nicotine-related research studying cognitive functioning, but also in studies examining nicotine dependence and addictive mechanisms.