| Poster |
Elizabeth Will
Appalachian State University
Subject Listing - Psychology
Advisor: Dr. Mark Zrull
Thursday, Poster Session 2, Presentation Kiosk 29 C, Health & Fitness Center
AGE AND SEIZURE FREQUENCY AFFECT SEVERITY OF SOUND-INDUCED SEIZURES IN JUVENILE RATS
Epilepsy is a disorder characterized by abnormal excitatory activity in the brain and behaviorally by seizures. With each seizure, the afflicted animal suffers brain injury that can make future seizures more severe. In this study, an acquired, sound-induced epilepsy model was used to examine the importance of age and seizure frequency on severity of a seizure disorder in juvenile rats. Twenty-five rats were made susceptible to sound-induced seizures (AGS) by priming on postnatal day (pnd) 18, which consists of exposure to 10 kHz tone pips for 8 min, and testing for seizure activity on pnd 32 through exposure to 120 dB broadband noise until clonus (i.e., a type of "grand mal" seizure). One group of rats (n=10) then experienced a seizure once every 3 days between pnds 35 and 62 (spaced AGS). The other groups experienced massed seizures (2/day for 5 days) early in adolescence between pnds 35 and 39 (n=6, early AGS) or later in life between pnds 58 and 62 (n=9, late AGS). Latency to a clonic seizure was used as a measure of AGS severity. The spaced and late massed AGS rats averaged 21.2% shorter latency to clonus (M=39.9 s, SD=11.2) than the early massed group (M=50.6-s, SD=11.2), F(2,22)=5.11, p<.05. The groups did not exhibit statistically significant differences in the duration of seizures, which averaged 24.4-s (SD=12.2) across the groups and is used to measure the intensity of AGS activity. These results suggest that being younger is more important to reducing the severity of the seizure disorder examined in this study than the frequency with which an animal experience AGS events (spaced or massed). Young animals often experience less change in behavior following brain injury, in this case severity of clonic seizures, than older animals.
Advisor: Dr. Mark Zrull, Associate Professor, Psychology, Appalachian State University, Boone, NC