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Interictal spikes as measured in the EEG result from the synchronized discharges of a group of hippocampal neurons. (Adapted, with permission, from
Wong, Miles, and Traub 1984.)
A. Rhythmic firing is evident in an intracellular recording from a pyramidal cell in a hippocampal slice. An extracellular recording from the same slice
shows the synchronized discharge of many neurons. This type of synchronized activity underlies interictal spikes in the EEG.
B. The hippocampal slice was perfused with bicuculline, which blocks the inhibition mediated by GABAA receptors in pyramidal cells and increases the
occurrence ofSource:
seizure-like
activity.
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recording
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shows
several action potentials in one cell (top trace). On the next trial (lower
Seizures
and Epilepsy,
Principles
of Neural
Editon
trace) a hyperpolarizing
current
was
injected
to
prevent
the
cell
from
firing,
revealing
shift that
the sudden
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Available
and long-lasting firing
of
neurons
in
a
seizure
focus.
at: http://mhmedical.com/ Accessed: May 13, 2017
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