Effects of Amphetamine and Nicotine on Auditory Gating: An Animal Model of Schizophrenia
Taylor, Jocelyn C.
Schizophrenia is a psychotic disorder that affects 1% of the population. People suffering from this disorder suffer from a number of different problems such as hallucinations, delusions, disorganized speech, grossly disorganized or catatonic behavior, affective flattening (lack of emotional response), alogia (lack of thought fluency and productivity), avolition (lack of initiation of actions) and social isolation. Current research is focusing on a phenomenon known as sensory gating. Many studies have concluded that there is a deficiency in sensory gating that may cause some of the more severe symptoms (i.e., delusions and hallucinations). A particular response being investigated is suppression of the auditory evoked P50 potential recorded by cortical EEG. A similar response found in the rat, the N40 auditory-evoked response is measured using hippocampal central nervous system recording. Amphetamine was injected intravenously (which is known to induce psychosis) causes deficient sensory gating in the rat. Drug X (the name cannot be disclosed due to confidentiality) was then administered to determine if the auditory-evoked N40 response could be normalized. The research team frequently found that the N40 response returned to normal sensory gating after administration of Drug X, thus reversing the amphetamine-induced gating deficit. This study implies that normalizing sensory gating can control many of the severe symptoms associated with Schizophrenia. Furthermore, the effects of chronic nicotine were tested in hopes of explaining the abundance of smokers in psychotic patients. Nicotine treatment failed to interact with sensory gating or alter amphetamine-induced gating deficit.
vi, 29 p.
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