Monoamine variability in the chronic model of atypical absence seizures.
OBJECTIVE
We studied the variability of the slow-spike-and-wave discharges (SSWDs) derived from AY-9944 (AY) treatment during brain development of Long-Evans hooded (LEh) rats.


METHODS
Although all LEh rats received the standard dose of AY (7.5 mg/kg), we have observed an intersubject variability of the total SSWD duration at postnatal day (P) 55. Therefore, we set out to investigate the underlying brain levels of norepinephrine (NE), dopamine (DA), and serotonin (5-HT) and its metabolite (5-HIAA), as determined by high-performance liquid chromatography (HPLC) analyses from four different brain regions: thalamus (Th), frontoparietal cortex (Cx), hippocampus (Hp), and brainstem (Bs).


RESULTS
All brains were obtained after two baseline electrocorticographic (ECoG) recordings with characteristic chronic, recurrent, bilaterally synchronous 4-6 Hz SSWD, at P 55 (336.25 +/- 97.23 s/h) and P60 (494.50 +/- 150.36 s) (r = 0.951, r(2) = 0.904, p < 0.005, Pearson product). The thalamic NE levels and the brainstem NE, DA, and 5HT levels were all significantly correlated with baseline SSWD duration at P55 and P60 (p < 0.01, Pearson product).


CONCLUSIONS
Our data indicate that brain monoamine levels may determine the intersubject variability of SSWD duration in AY rats with chronic atypical absence seizures.
Bercovici
Eduard
E
Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Cortez
Miguel A
MA
Wang
Xiaomei
X
Snead
O Carter
OC
D000818:Animals; D000831:Animals, Newborn; D015306:Biogenic Monoamines / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004195:Disease Models, Animal; D004563:Electrochemistry / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D004832:Epilepsy, Absence / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride
D015306:Biogenic Monoamines; D018377:Neurotransmitter Agents; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride