THE EFFECTS OF PARTIAL BILATERAL LESIONING OF SUBSTANTIA NIGRA IN A GENETIC ABSENCE EPILEPSY RAT MODEL

Year 2002, Volume: 15 Issue: 2, 79 - 85, 03.12.2016

Zafer Gören Rezzan Aker Filiz Onat Aydan Ergün

Abstract

Objective: "Genetic Absence Epilepsy Rats from
Strasbourg" (GAERS), an inbred Wistar strain,
serve as an experimental venue. These rats
generate spontaneous spike-and-wave
discharges (SWD) and have increased yaminobutyric
acid (GABA) levels in the
ventrolateral thalamus (VLT). Recently,
substantia nigra pars reticulata (SNpr) was
reported to act as an endogeneous inhibitory
mechanism in the generation, onset and
maintenance of various types of seizures. The
presence of tonic control exerted by SNpr in
absence seizures should also be tested in
GAERS.
Methods: In this current study, GABA and Lglutamic
acid release in VLT of GAERS with
partial bilateral electrolytic lesions of SNpr was
evaluated by using microdialysis technique with
fluorescent detection.
Results: GABA levels in VLT were 0.12±0.04 pM
and 0.24±0.08 pM in sham-lesioned and SNprlesioned
GAERS, respectively. L-glutamic acid
level was found to be 0.415±0.150 pM in shamlesioned
group and 0.324±0.094 pM in SNprlesioned
GAERS. Statistical analysis revealed no
significant difference between sham-lesioned
and SNpr-lesioned rats. The number and the
duration of SWD were also similar in two groups.
Conclusion: These findings show that SNpr
does not exert a tonic control in GAERS and we
assume that intact SNpr acts as a site that may
exert an inhibition on target structures when
activated in GAERS.
Key Words: GAERS (Genetic Absence
Epilepsy Rats from Strasbourg), GABA (yaminobutyric
acid), Substantia nigra,
Ventrolateral thalamus, Absence epilepsy,
Microdialysis, Nigral control of epilepsy.

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