Premium
Imaging Epileptiform Discharges in Slices of Piriform Cortex with Voltage‐sensitive Fluorescent Dyes
Author(s) -
DEMIR REZAN,
HABERLY LEWIS B.,
JACKSON MEYER B.
Publication year - 2000
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2000.tb06740.x
Subject(s) - piriform cortex , neocortex , ictal , epileptogenesis , neuroscience , plateau (mathematics) , depolarization , neurotransmission , cortex (anatomy) , chemistry , electroencephalography , biophysics , epilepsy , biology , hippocampus , mathematical analysis , biochemistry , receptor , mathematics
A bstract : Voltage imaging techniques were used to investigate epileptiform discharges in brain slices containing piriform cortex (PC). These experiments pinpointed the site of discharge onset in the endopiriform nucleus (En). Under some conditions, discharge onset also occurred simultaneously in adjoining neocortex. With slightly suprathreshold electrical stimulation, discharge generation was a two‐stage process in which onset was preceded by a sustained spatially localized depolarization denoted as plateau activity. Plateau activity was seen away from the onset site, in a border region between En and layer III of PC. A similar two‐stage sequence was seen for slices taken from a variety of planes, using two different interictal models as well as an ictal model. Plateau activity was found to be necessary for the generation of both kinds of discharge. Synaptic transmission at the site of onset was found to be required for the generation of interictal‐like discharges, but ictal‐like discharges were different in that they could still be generated when synaptic transmission at this site was impaired. These studies identify specialized regions with potentially important roles in epileptogenesis and help to elucidate the neuronal circuitry that can produce epileptiform activity.