SLEEP 2011 Abstract Supplement

A. Basic Science V. Physiology
influence of sleep on seizure occurrence, whereas disturbances in the
sleep-wake continuum in epilepsy patients are common but often overlooked.
Therefore, we employed kindling stimuli delivered at different
zeitgeber time (ZT) points to elucidate the effect of epilepsy on the alterations
of sleep homeostasis.
Methods: Rapid amygdala kindling protocol was delivered at different
ZT points (ZT0 [light onset], ZT6 [middle of light period] and ZT12
[dark onset]) to induced temporal lobe epilepsy (TLE) in rats. EEGs
and sleep activities were recorded after reaching full-blown epilepsy.
ELISA, ribonuclease protection assay and immunocytochemistry were
employed to measure corticosterone, interleukin (IL)-1 and Per1 protein
expression, respectively.
Results: SWS and REM sleep decreased during the first 12-hour light
period when rats were kindled at ZT0. When ZT12 kindling was given,
SWS increased but REM sleep was not altered during the first 12-hour
dark period. However, the 12:12h sleep-wake circadian rhythm was not
altered. Corticosterone concentrations were increased after ZT0 kindling
and the expression of IL-1 was enhanced after ZT12 kindling. Furthermore,
corticotrophin-releasing hormone (CRH) receptor antagonist and
IL-1 receptor antagonist (IL-1ra) respectively blocked ZT0- and ZT12-
induced sleep alterations. In addition, the expression of Per1 protein in
the suprachiasmatic nucleus (SCN) was shifted 6 hours in advance and
sleep circadian was advanced 2 hours when kindling stimuli was given
at ZT6. Microinjection of hypocretin receptor antagonist, SB 334867,
directly into the SCN significantly blocked ZT6-kindling induced advance
shifting of Per1 expression in SCN and the alteration of sleep
circadian.
Conclusion: Amygdala-kindling stimuli delivered at different ZT points
may alter the circadian and/or homeostatic factors, indicating the underlying
mechanisms for the sleep disturbances in epilepsy patients.
0148
ASHWAGANDHA PROVIDES NEUROPROTECTION
AGAINST APNEA-INDUCED NEURONAL DEGENERATION
IN THE HIPPOCAMPUS OF ADULT GUINEA PIGS
Chase MH 1,2,3 , Zhang J 1,2 , Fung SJ 1,2 , Xi M 1,2 , Sampogna S 1
1
Websciences International, Los Angeles, CA, USA, 2 VA Greater Los
Angeles Healthcare System, Los Angeles, CA, USA, 3 UCLA School of
Medicine, Los Angeles, CA, USA
Introduction: Chronic recurrent apnea induces marked increases in
neurodegeneration (apoptosis) in the hippocampus. This effect occurs
as a result of an excitotoxic influx of Ca2+ ions, which is due to an abnormal
increase in glutamatergic neurotransmission induced by apnea.
It has been shown that apnea-induced excitotoxicity and the accompanying
neurodegenerative processes are ameliorated by the activation of
inhibitory inputs from GABAergic neurons. Consequently, we hypothesized
that ashwagandha, which has been suggested to act as a GABAmimetic,
might prevent and/or reduce apnea-induced neurodegeneration
in the hippocampus.
Methods: Adult guinea pigs were anesthetized with α-chloralose and
immobilized with Flaxedil. Apnea was induced by ventilatory arrest in
order to desaturate the oxyhemoglobin to 75% SpO2; ventilation was
then resumed; following recovery to >95% SpO2, a succeeding apneic
episode was initiated. This sequence of apnea, followed by ventilation
with recovery of SpO2, was repeated for a period of 2 hours. Ashwagandha
was injected, unilaterally, into the CA1 region of the hippocampus
(400 mg, 0.20 µl) at a site where the largest amplitude of the
field EPSP in CA1 neurons was recorded following stimulation of CA3.
Injections were performed 15 minutes prior to the onset of the first episode
of apnea and thereafter once every 30 minutes. Subsequently, the
animals were perfused; brain sections were obtained and immunostained
with a mouse monoclonal antibody raised against single-stranded DNA
(ssDNA) (which is a biomarker for apoptosis).
Results: Under light microscopy, numerous neurons were labeled with
the antibody against ssDNA on the side of the hippocampus that was
not injected with ashwagandha. There was mass precipitation of DAB
reaction products in the nuclei and the cytoplasm of these neurons. In
contrast, on the side of the hippocampus in which ashwagandha was
injected, there were few ssDNA positive neurons. In addition, the intensity
of immunostaining within these cells was remarkably less compared
with that present in cells on the contralateral side.
Conclusion: These data indicate that ashwagandha is able to prevent or
reduce apnea-induced neuronal apoptosis in the hippocampus.
Support (If Any): This research was supported by Brain Sciences
Foundation.
SLEEP, Volume 34, Abstract Supplement, 2011
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