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Updated: Sep 26, 2026
Elevated Plus Maze Test Combined with Video Tracking Software to Investigate the Anxiolytic Effect of Exogenous Ketogenic Supplements
Published on: January 7, 2019
Corticotropin releasing factor antagonist, alpha-helical CRF(9-41), reverses nicotine-induced conditioned, but not
Sonia Tucci1, Survjit Cheeta, Pallab Seth
1Psychopharmacology Research Unit, Centre for Neuroscience, GKT School of Biomedical Sciences, King's College London, UK. sonia.tucci@kci.ac.uk
Rationale:
Unconditioned anxiogenic effects of nicotine have been observed in the social interaction (SI) test 5 min after injection of a low dose and both 5 min and 30 min after injection of a high dose. Conditioned anxiety has also been observed 24 h after testing in the SI with a high dose of nicotine.
Objectives:
In order to determine whether these three anxiogenic effects shared a common mechanism, we investigated the role of corticotropin releasing factor (CRF). We therefore examined whether the CRF antagonist alpha-helical CRF(9-41) could block these three anxiogenic effects of nicotine.
Methods:
To test the unconditioned anxiogenic effects, pairs of male rats were tested in SI 5 min after s.c. vehicle or nicotine (0.1 mg/kg) or 30 min after s.c. vehicle or nicotine (0.45 mg/kg), and 30 min after i.c.v. artificial cerebrospinal fluid (aCSF) or alpha-helical CRF(9-41). To test conditioned anxiety, rats were exposed to the SI test on day 1, 5 min after vehicle or nicotine (0.1 mg/kg). On day 2, they were re-tested in SI 30 min after i.c.v. aCSF or alpha-helical CRF(9-41) (5 microg).
Results:
alpha-Helical CRF(9-41) did not block the unconditioned anxiogenic effect of either dose of nicotine. Nicotine (0.1 mg/kg, 5 min) elicited a conditioned anxiogenic response that was significantly reversed by alpha-helical CRF(9-41). The CRF antagonist alone had no effect.
Conclusions:
CRF is an important mediator of the conditioned anxiety to nicotine, but may not play a role in mediating the acute anxiogenic effects.
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