Date of Award
2010
Degree Type
Thesis
Degree Name
Master of Science
Program
Anatomy and Cell Biology
Supervisor
Dr. Susanne Schmid
Second Advisor
Dr. Arthur Brown
Third Advisor
Dr. Steven Laviolette
Abstract
Individuals with schizophrenia have impairments in prepulse inhibition of startle (PPI) which correlates with cognitive deficits. Nicotine improves the performance of patients and healthy individuals with PPI deficits on PPI tests. We hypothesized that nicotine directly affect startle-mediating neurons of the caudal pontine recticular nucleus (PnC) of the brainstem using electrophysiological recordings. The data revealed that nicotine (10 pM) increases leak current amplitude, reduces membrane resistance, and depolarizes the resting membrane potential. Nicotine had no significant effect on the EPSC amplitude for neither the trigeminal nor auditory stimulations. All effects were reversed only by a high dose (10 pM) of the a-j nAChR antagonist MLA and a low dose of TMPH (lOOnM; antagonizes all but the a7 nAChR). The effect of nicotine persisted in the presence of cadmium (100 pM), which blocks synaptic transmission. These results confirm the functional expression of nAChRs in the PnC and suggest a role of nAChRs in modulating startle responses directly in the brainstem.
Recommended Citation
Pinnock, Farena S., "Nicotine has a Direct Effect on Brainstem Startle-Mediating Neurons" (2010). Digitized Theses. 4084.
https://ir.lib.uwo.ca/digitizedtheses/4084