Pharmacological modulation of photically evoked afterdischarge patterns in hooded Long-Evans rats

Research paper by Erin D. Bigler, Donovan E. Fleming, Donald E. Shearer

Indexed on: 07 Nov '13Published on: 07 Nov '13Published in: Bulletin of the Psychonomic Society


The pharmacological modulation of photically evoked afterdischarge (AD) patterns within a short-term habituation paradigm were examined in the hooded Long-Evans rat. Pharmacological arousal by amphetamine, pilocarpine, and physostigmine or induced thalamic suppression by trimethadione (Tridione) attenuated AD development. AD development was unaffected by saline, methyl atropine, and atropine. Pentylenetetrazol (Metrazol) was used as an AD potentiator and, as such, enhanced AD development following all drug conditions except within the physostigmine and methyl atropine sessions. It was determined that in the hooded rat AD varies only as a function of drug injected; time (habituation) was not a factor. The role of the reticulocortical projection system and the limbic system was incorporated in the explanation of the results. Significant differences were also noted between the pharmacology of AD parameters in hooded vs albino rats.