Decreased dopamine and increased norepinephrine levels in the spontaneously epileptic rat, a double mutant rat.
Dopamine (DA) and norepinephrine (NE) brain levels and turnover rate were examined in the spontaneously epileptic rat (SER: zi/zi, tm/tm), a double mutant rat obtained by mating tremor heterozygotes (tm/+) with zitter homozygotes associated with epileptic seizures composed of spontaneously occurring tonic convulsion and absence-like seizure. DA and NE levels were also determined in age-matched male zitter, tremor and Kyo: Wistar rats. DA levels in caudate nucleus were significantly lower in adult age (10-12 weeks) SER, which showed epileptic seizures, and zitter rats than in adult Kyo: Wistar and tremor rats. DA levels in other areas such as thalamus-hypothalamus, midbrain, and pons medulla were not different among SER, zitter, tremor, and Kyo: Wistar rats at age 10-12 weeks. Except in cerebral cortex and hippocampus, there were no differences in brain DA levels between young seizure-free SER (age 5 weeks) and young Kyo: Wistar rats. Furthermore, the turnover rate of DA was significantly lower in caudate nucleus of adult SER than of Kyo: Wistar rat, whereas in pons-medulla there was no difference between the two strains. In contrast, NE levels in the thalamus-hypothalamus, midbrain, cerebellum and pons-medulla were higher in SER and zitter rats at age 10-12 weeks than in age-matched tremor and Kyo: Wistar rats. Higher NE levels were also observed in midbrain, cerebellum, and pons-medulla of young SER as compared with young Kyo: Wistar rats. Turnover rates of NE were significantly lower in pons-medulla and cerebellum of the adult SER than in those of Kyo: Wistar rat.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Pharmacology, Faculty of Medicine, Kyoto University, Japan.
M
M
Hara
M
M
Sasa
A
A
Kawabata
T
T
Serikawa
T
T
Yamada
J
J
Yamada
S
S
Takaori
D000367:Age Factors; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry / Q000235:genetics*; D004298:Dopamine / Q000032:analysis / Q000378:metabolism*; D004827:Epilepsy / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008959:Models, Neurological; D009638:Norepinephrine / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D011921:Rats, Inbred WKY; D011922:Rats, Mutant Strains; D013045:Species Specificity
D004298:Dopamine; D009638:Norepinephrine