First Name:
Chase
Last Name:
Francis
Major Department:
Biology & Psychology
Thesis Director:
Mark Zrull
Date of Thesis:
May 2011
Chronic generalized seizures can cause widespread brain damage, particularly in the hippocampus and amygdala, resulting in learning or memory problems, as well as anxiety or other emotional disturbances. Current drug therapies do not work for all individuals with generalized convulsive or grand mal seizures, and there is some indication that anticonvulsant drugs cause cognitive problems compounding common consequences ofchronic epilepsy. ~ Environmental enrichment (EE) is one therapy that can mitigate brain injury and resultant cognitive and behavioral deficits. In this study, audiogenic seizures were induced in Long-Evans rats, and a group ofthese rats received EE as an ongoing treatment while not enriched seizure- prone rats and normal rats served as controls. Rats were tested in a novel location preference task to assess spatial memory and fear ofobjects. No differences were seen in location preference; however, in comparison to other groups, seizure rats showed increased anxiety to objects in the open field spending less time by objects in the field than other groups. As expected, enrichment prevented increased fear to objects in the field in seizure rats. Rats were also tested in a delayed alternation task to assess procedural and working memory o f enriched and non-enriched seizure rats. It took longer for seizure rats to learn the delayed alternation task than other groups, indicating impairments in procedural memory. Enriched seizure rats learned as quickly as other groups indicating a therapeutic effect ofenrichment. No differences were seen across groups in performance ofthe task. Results indicate that enrichment can have a therapeutic effect on anxiety-driven behaviors and a protective effect on learning. Therapeutic and protective effects to behaviors may be mediated by beneficial changes within the hippocampus and amygdala.