Fig. 1. Electrode implantation. (A) Locations of electrodes implantation on the
skull, FC = frontal cortex, PC = parietal cortex, CB = cerebellum, red arrow
indicate bregma. (B) Levels of implanted electrodes were approximately even to
the inner surface of skull. (C and D) All electrodes were bound together and
secured on the skull. Scale bar indicate 1 cm.
RESULTS AND DISCUSSION
Effects of ethanol withdrawal and treatment with MS alkaloid (60 mg/kg) were analyzed from EEG signal
recorded for 8-h period following ethanol withdrawal. Theta powers were increased in ethanol withdrawal group
compared to those of non-ethanol withdrawal in frontal (
F
(23, 119) = 2.59,
p <
0.001) (Fig. 2 A) and parietal cortices
(
F
(23, 119) = 10.27,
p <
0.001) (Fig. 2 B). However, these increases were significantly prevented by the MS alkaloid.
In addition, ethanol withdrawal significantly increased total awake period (
F
(2, 14) = 21.28,
p <
0.001) and
treatment with MS alkaloid did not prevent this effect (Fig. 3).
This study showed CNS hyperactivity in terms of theta power and total awake period increases following
ethanol withdrawal. Attenuation of ethanol withdrawal-induced increase of theta power may indicate effectiveness of
MS alkaloid treatment. By the way, this MS alkaloid did not affect the induced awake period. Previously, this MS
alkaloid was found to mediate CNS effect at least partly via serotonin enhancement (Matsumoto et al., 1996; Matsumoto
et al., 1997). Thus, the MS alkaloid may promote wakefulness and could not reduce total awake period-induced by
ethanol withdrawal.
However, this extract reduced CNS hyperactivity during ethanol withdrawal period. Although wakefulness
was not attenuated by the MS alkaloid extract, this treatment may be considered at least mentally effective.
C
D
A
B
