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-193230293
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Neurons FiringProperties
65 records
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response to depolarization of the soma by injected current. No intrinsic
bursters or fast spiking cells (Connors and Gutnick 1990) were recorded."p.505
"In this cell inotophoresis (-60 nA) at a site 460 µM from the soma on the
apical dendrite evoked an initial, low-threshold, slow, action potential on
which was superimposed a higher-threshold, fast spike (Fig. 1, black trace).
The different time courses and thresholds of the fast and slow spikes are not
obvious at the slow sweep speed used in this figure (cf. Schwindt and Crill
1997). Similar fast spikes were eliminated by TTX application, and similar
slow spikes were eliminated by Cd2+ application (see following text). The
membrane potential response during the remainder of this iontophoresis
remained subthreshold for action potential initiation. A slightly larger
iontophoretic current (-70 nA) again evoked the initial Ca2+ and Na+ spikes,
which were then followed by a long-duration action potential (the plateau)
that repolarized only when the iontophoretic current was terminated (Fig. 1,
green trace). In all cells tested, a larger iotophoretic current (-80 nA in
Fig. 1) decreased the latency to plateau initiation but did not increase
plateau amplitude (Fig. 1, red trace). Similar plateaus were evoked by focal
iontophoresis of glutamate at 22 identified sited on the apical dendrite in
different experiments."pp.505-506
