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Disturbance of Motivated Behavior in Rats by
Epileptic Afterdischarges
P. MAREŠ, L. CHOCHOLOVÁ
Institute of Physiology, Academy of Sciences of the Czech
Republic, Prague, Czech Republic
Summary
Nearly all epileptic seizures in patients are characterized by
deranged consciousness. We started to study changes in motivated
behavior (drinking in thirsty rats) as a possible analogue of
compromised consciousness during and after epileptic seizures.
Epileptic afterdischarges (ADs) were elicited by stimulation of
the dorsal hippocampus and/or thalamus. Rats with implanted
electrodes (deprived of water for 24 hours) were trained to lick
water from a narrow tube. After pretraining ADs were elicited
eight times in each animal and access to water was allowed
during different phases of the AD. Stimulation did not affect
licking if no AD was induced. If stimulation was successful,
licking was stopped in nearly 70 % of stimulations and modified
(biting the tube) in 30 %. Hippocampal ADs (characterized by
serrated waves in the EEG and by an arrest of behavior with
subsequent automatisms) completely blocked licking, signs of
recovery appeared during the interval between the AD and
recurrent AD and it progressed during recurrent ADs. Thalamic
ADs abolished licking in 82% of cases and immediately after ADs
normal licking reappeared in 49 % of these observations. Our
results suggest that changes in motivated behavior might serve
as an analogue of compromised human consciousness.
Key
words
Epileptic seizures • Rat • Hippocampus • Thalamus • Behavior
Reprint
requests
Prof. P. Mareš, M.D., D.Sc., Institute of Physiology, Academy of
Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4,
Czech Republic. E-mail:
maresp@biomed.cas.cz
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