43 research outputs found
Migrations des poissons démersaux le long des côtes ouest-africaines de 10 à 24° de latitude nord
The GABA-Withdrawal Syndrome: A Model of Local Status Epilepticus
The GABA-withdrawal syndrome (GWS)
is a model of local status epilepticus following
the interruption of a chronic GABA infusion
into the rat somatomotor cortex. GWS is
characterized by focal epileptic electroencephalographic
discharges and associated contralateral
myoclonus. In neocorticai slices obtained
from GWS rats, most neurons recorded in the
GABA-infused area are pyramidal neurons
presenting bursting properties. The bursts are
induced by white-matter stimulation and/or
intracellular depolarizing current injection
and correlate with a decrease of cellular
sensitivity to GABA, caused by its prolonged
infusion. This effect is related to a calcium
influx that may reduce the GABAA
receptormediated
inward current and is responsible
for the bursting properties. Here we present
evidence for the involvement of calcium- and
NMDA-induced currents in burst genesis. We
also report modulatory effects of noradrenaline
appearing as changes on firing patterns of
bursting and nonbursting cells. Complementary
histochemical data reveal the existence of a
local noradrenergic hyperinnervation and an
ectopic expression of tyrosine hydroxylase
mRNAs in the epileptic zone