Effects of nicotine vary across two auditory evoked potentials in the mouse.
BACKGROUND
Schizophrenia patients display sensory processing deficits, reduced alpha7-nicotine receptor expression, and increased incidence of smoking, prompting investigation of nicotine receptor agonists as possible treatments. We evaluated the effects of acute and chronic nicotine, using an animal model that incorporates genetic variation for sensory processing and nicotine sensitivity.


METHODS
C57BL/6J and DBA/2Hsd mice received 2 weeks of 4.2 mg/kg chronic nicotine or saline. Auditory evoked potentials were recorded before and after acute nicotine injection of 1.05 mg/kg on day 14, with a paired-click paradigm (S1/S2). Amplitude and gating of the P20 and N40 were compared between conditions.


RESULTS
Acute nicotine increased the amplitude and gating of the P20 and decreased the amplitude and gating of the N40 across all groups, primarily by acting on S1. Chronic nicotine attenuated the effects of acute nicotine on the N40.


CONCLUSIONS
Our data support the notion that the mouse P20 shares pharmacological response properties with the human P50. In addition, findings suggest that nicotine might increase the initial sensory response (S1), with a resulting improvement in gating of some components.
Stanley Center for Experimental Therapeutics in Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Kayla L
KL
Metzger
Christina R
CR
Maxwell
Yuling
Y
Liang
Steven J
SJ
Siegel
D000161:Acoustic Stimulation; D000704:Analysis of Variance; D000818:Animals; D003367:Cotinine / Q000097:blood; D004334:Drug Administration Schedule; D004569:Electroencephalography / Q000145:classification; D005072:Evoked Potentials, Auditory / Q000187:drug effects* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009538:Nicotine / Q000097:blood / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000097:blood / Q000494:pharmacology*
D018722:Nicotinic Agonists; D009538:Nicotine; D003367:Cotinine