Effects of spike parameters and neuromodulators on action potential waveform-induced calcium entry into pyramidal neurons

Ansalan E. Stewart, Robert Foehring

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Neocortical pyramidal neurons express several different calcium channel types. Previous studies with square voltage steps have found modest biophysical differences between these calcium channel types as well as differences in their modulation by transmitters. We used acutely dissociated neocortical pyramidal neurons to test whether this diversity extends to different activation by physiological stimuli. We conclude that 1) peak amplitude, latency to peak, and the total charge entry for the Ca2+ channel current is dependent on the shape of the mock action potential waveforms (APWs). 2) The percent contribution of the five high-voltage-activated currents to the whole cell current was not altered by using an APW as opposed to a voltage step to elicit the current. 3) The identity of the charge carrier affects the amplitude and decay of the whole cell current. With Ca2+, there was a greater contribution of T-type current to the whole cell current. 4) Total Ba2+ charge entry is linearly dependent on the number of spikes in the stimulating waveform and relatively insensitive to spike frequency. 5) Current decay was greatest with Ca2+ as the charge carrier and with minimal internal chelation. 6) Voltage-dependent neurotransmitter-mediated modulations can be reversed by multiple spikes. The extent of the reversal is dependent on the number of spikes in the stimulating waveform. Thus the neuronal activity pattern can determine the effectiveness of voltage-dependent and -independent modulatory pathways in neocortical pyramidal neurons.

Original languageEnglish (US)
Pages (from-to)1412-1423
Number of pages12
JournalJournal of Neurophysiology
Volume85
Issue number4
StatePublished - Apr 19 2001

Fingerprint

Pyramidal Cells
Action Potentials
Neurotransmitter Agents
Calcium Channels
Calcium

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Physiology

Cite this

Effects of spike parameters and neuromodulators on action potential waveform-induced calcium entry into pyramidal neurons. / Stewart, Ansalan E.; Foehring, Robert.

In: Journal of Neurophysiology, Vol. 85, No. 4, 19.04.2001, p. 1412-1423.

Research output: Contribution to journalArticle

@article{8f23137ffa6044a6b7fd664ca4108ee5,
title = "Effects of spike parameters and neuromodulators on action potential waveform-induced calcium entry into pyramidal neurons",
abstract = "Neocortical pyramidal neurons express several different calcium channel types. Previous studies with square voltage steps have found modest biophysical differences between these calcium channel types as well as differences in their modulation by transmitters. We used acutely dissociated neocortical pyramidal neurons to test whether this diversity extends to different activation by physiological stimuli. We conclude that 1) peak amplitude, latency to peak, and the total charge entry for the Ca2+ channel current is dependent on the shape of the mock action potential waveforms (APWs). 2) The percent contribution of the five high-voltage-activated currents to the whole cell current was not altered by using an APW as opposed to a voltage step to elicit the current. 3) The identity of the charge carrier affects the amplitude and decay of the whole cell current. With Ca2+, there was a greater contribution of T-type current to the whole cell current. 4) Total Ba2+ charge entry is linearly dependent on the number of spikes in the stimulating waveform and relatively insensitive to spike frequency. 5) Current decay was greatest with Ca2+ as the charge carrier and with minimal internal chelation. 6) Voltage-dependent neurotransmitter-mediated modulations can be reversed by multiple spikes. The extent of the reversal is dependent on the number of spikes in the stimulating waveform. Thus the neuronal activity pattern can determine the effectiveness of voltage-dependent and -independent modulatory pathways in neocortical pyramidal neurons.",
author = "Stewart, {Ansalan E.} and Robert Foehring",
year = "2001",
month = "4",
day = "19",
language = "English (US)",
volume = "85",
pages = "1412--1423",
journal = "Journal of Neurophysiology",
issn = "0022-3077",
publisher = "American Physiological Society",
number = "4",

}

TY - JOUR

T1 - Effects of spike parameters and neuromodulators on action potential waveform-induced calcium entry into pyramidal neurons

AU - Stewart, Ansalan E.

AU - Foehring, Robert

PY - 2001/4/19

Y1 - 2001/4/19

N2 - Neocortical pyramidal neurons express several different calcium channel types. Previous studies with square voltage steps have found modest biophysical differences between these calcium channel types as well as differences in their modulation by transmitters. We used acutely dissociated neocortical pyramidal neurons to test whether this diversity extends to different activation by physiological stimuli. We conclude that 1) peak amplitude, latency to peak, and the total charge entry for the Ca2+ channel current is dependent on the shape of the mock action potential waveforms (APWs). 2) The percent contribution of the five high-voltage-activated currents to the whole cell current was not altered by using an APW as opposed to a voltage step to elicit the current. 3) The identity of the charge carrier affects the amplitude and decay of the whole cell current. With Ca2+, there was a greater contribution of T-type current to the whole cell current. 4) Total Ba2+ charge entry is linearly dependent on the number of spikes in the stimulating waveform and relatively insensitive to spike frequency. 5) Current decay was greatest with Ca2+ as the charge carrier and with minimal internal chelation. 6) Voltage-dependent neurotransmitter-mediated modulations can be reversed by multiple spikes. The extent of the reversal is dependent on the number of spikes in the stimulating waveform. Thus the neuronal activity pattern can determine the effectiveness of voltage-dependent and -independent modulatory pathways in neocortical pyramidal neurons.

AB - Neocortical pyramidal neurons express several different calcium channel types. Previous studies with square voltage steps have found modest biophysical differences between these calcium channel types as well as differences in their modulation by transmitters. We used acutely dissociated neocortical pyramidal neurons to test whether this diversity extends to different activation by physiological stimuli. We conclude that 1) peak amplitude, latency to peak, and the total charge entry for the Ca2+ channel current is dependent on the shape of the mock action potential waveforms (APWs). 2) The percent contribution of the five high-voltage-activated currents to the whole cell current was not altered by using an APW as opposed to a voltage step to elicit the current. 3) The identity of the charge carrier affects the amplitude and decay of the whole cell current. With Ca2+, there was a greater contribution of T-type current to the whole cell current. 4) Total Ba2+ charge entry is linearly dependent on the number of spikes in the stimulating waveform and relatively insensitive to spike frequency. 5) Current decay was greatest with Ca2+ as the charge carrier and with minimal internal chelation. 6) Voltage-dependent neurotransmitter-mediated modulations can be reversed by multiple spikes. The extent of the reversal is dependent on the number of spikes in the stimulating waveform. Thus the neuronal activity pattern can determine the effectiveness of voltage-dependent and -independent modulatory pathways in neocortical pyramidal neurons.

UR - http://www.scopus.com/inward/record.url?scp=0035073252&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035073252&partnerID=8YFLogxK

M3 - Article

VL - 85

SP - 1412

EP - 1423

JO - Journal of Neurophysiology

JF - Journal of Neurophysiology

SN - 0022-3077

IS - 4

ER -