Objective: 

Skin conductance (electrodermal activity, EDA) measurements reflect sympathetic tone. EDA is frequently used as an indirect measure of stress. Selective depletion of forebrain noradrenaline has been shown to potentiate various types of experimentally induced seizures. The aim of this study was to investigate sympathetic activity and stress condition with EDA in pentylenetetrazole-kindled rats and was to test whether environmental enrichment alters responsiveness of pituitary-adrenocortical and sympathetic response in these rats.

Methods: 

We separated animals into four different groups. The control group in normal cage (CN), the control group in enrichment cage (CE), epileptic group in normal cage (EN), the epileptic group in enrichment cage (EE). Serum physiologic and PTZ (35 mg/kg, ip) were injected to control or epileptic group, respectively once every alternate day for a period of 38 days. After a week from the last injection, EDA was recorded from rat's planter surface of posterior extremities using Ag/AgCl electrodes. Tonic and phasic (response to 15 auditory stimuli) skin conductance levels (SCL) were taken.

Results: 

There were significant differences among the groups for tonic and phasic SCL. CN group had significantly higher SCL than CE, EN, EE groups. SCL of the control group when housed in enrichment cage were diminished. But, in epileptic group, SCL were not diminished. There were no significant differences between rats housed in normal and enrichment cages.

Conclusions: 

The data suggest that epileptic rats had diminished electrodermal activity due to by their relatively low noradrenaline content. Enrichment in environment did not seem to have an improving effect on sympathetic system in the epileptic rats.