An Evaluation Of The Effects Of Sub-Chronic Ketamine Exposure On Rodent Memory As Assessed By The Odor Span Task In Female Rats

Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Lisa Baker, Ph.D.

Second Advisor

Alan Poling, Ph.D.

Third Advisor

Kelly Kohler, Ph.D.

Fourth Advisor

Mark Galizio, Ph.D.


Female rats, ketamine, odor span task, Sprague Dawley, working memory


Though numerous studies have been undertaken to explore the mechanisms of action of antidepressant medications, little is known about the origins of the disorders they treat. Recently, the therapeutic value of ketamine as a treatment for depression was recognized by the Food and Drug Administration. Historically, ketamine has been used in the laboratory setting to induce ‘schizophrenia-like’ symptomology in humans and animals to allow for further study of those symptoms in a controlled environment; a correlation between ketamine use and deficits in memory and cognitive function has been suggested. This study evaluated the impact of sub-chronic sub-anesthetic ketamine on performance of the odor span task (OST), a behavioral assessment of working memory, in female Sprague-Dawley rats. The OST uses odor stimuli which are more salient to rats than visual or auditory stimuli. Reinforcement is attained by the subject when a response to a novel scent stimulus is emitted; responses to previously presented scents are not reinforced. Once trained to criterion the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine was administered according to a 10-day sub-chronic dosing regimen. When tested after a two-day washout period, the ketamine group (n = 7) did not show any deficits in performance at the measures of span (the number of correct trials between Trial 2 and the first error) or longest run (the greatest number of correct consecutive trials) as compared to the group that was administered saline (n = 6). These findings are congruent with similar studies which evaluated male Sprague-Dawley rats; however, further studies of rodent strain, age, and dosing regimen are warranted.

Access Setting

Dissertation-Open Access

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