Changes of visual evoked potential induced by lateral geniculate nucleus kindling in rats.
OBJECTIVE
The present study was undertaken to investigate the changes of visual evoked potential (VEP) induced by lateral geniculate nucleus (LGN) kindling in comparison with those induced by amygdala (AMG) and hippocampus (HPC) kindling in rats.


METHODS
Under pentobarbital anesthesia, the rats were fixed to a stereotaxic apparatus, and stainless steel electrodes were implanted into the LGN, AMG, HPC and the occipital cortex (OCOR). Bipolar stimulation was applied to the LGN, AMG or HPC every day until generalized seizure was obtained. VEP was recorded from the OCOR before the first day of electric stimulation (pre-kindled) and after the development of kindling (post-kindled).


RESULTS
After the development of LGN kindling, the amplitudes of early VEP components (P(1)-N(1) and N(1)-P(2)) were significantly augmented in comparison with those of pre-kindled rats. In addition, the duration of the photically evoked after-discharge burst (duration of VEP) was significantly prolonged by LGN kindling. On the other hand, in AMG and HPC kindling, no significant changes were observed in VEP between pre-kindled and post-kindled rats.


CONCLUSIONS
The changes of VEP observed in patients with photosensitive epilepsy are also demonstrated in animal study using LGN kindling.
Ishikawa
Takashi
T
Department of Medicinal Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka 1-1-1, Okayama 700-8530, Japan.
Fujiwara
Akinori
A
Takechi
Kenshi
K
Ago
Jun
J
Matsumoto
Naotaka
N
Rahman
Md Ashequr
MA
Kamei
Chiaki
C
D000679:Amygdala / Q000502:physiology; D000818:Animals; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005829:Geniculate Bodies / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology; D007696:Kindling, Neurologic / Q000502:physiology*; D008297:Male; D010775:Photic Stimulation; D051381:Rats; D017208:Rats, Wistar; D013238:Stereotaxic Techniques