Columnar distribution of activity dependent gabaergic depolarization in sensorimotor cortical neurons Public Deposited

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Creator
  • Whitsel, Barry
    • Affiliation: School of Medicine, UNC/NCSU Joint Department of Biomedical Engineering, Department of Cell Biology and Physiology
  • Woo, Junsung
    • Other Affiliation: WCI Center for Functional Connectomics, Institute of Science and Technology (KIST), Seoul, 136-791, Korea
  • Lee, Jaekwang
    • Affiliation: School of Medicine, UNC/NCSU Joint Department of Biomedical Engineering
    • Other Affiliation: WCI Center for Functional Connectomics, Institute of Science and Technology (KIST), Seoul, 136-791, Korea
  • Favorov, Oleg
    • Affiliation: School of Medicine, UNC/NCSU Joint Department of Biomedical Engineering
  • Lee, C
    • Other Affiliation: WCI Center for Functional Connectomics, Institute of Science and Technology (KIST), Seoul, 136-791, Korea
  • Tommerdahl, Mark Allen
    • Affiliation: School of Medicine
    • Other Affiliation: UNC/NCSU Joint Department of Biomedical Engineering
Abstract
  • Abstract Background GABA, the major inhibitory neurotransmitter in CNS, has been demonstrated to paradoxically produce excitation even in mature brain. However activity-dependent form of GABA excitation in cortical neurons has not been observed. Here we report that after an intense electrical stimulation adult cortical neurons displayed a transient GABA excitation that lasted for about 30s. Results Whole-cell patch recordings were performed to evaluate the effects of briefly applied GABA on pyramidal neurons in adult rodent sensorimotor cortical slice before and after 1 s, 20 Hz suprathreshold electrical stimulation of the junction between layer 6 and the underlying white matter (L6/WM stimulation). Immediately after L6/WM stimulation, GABA puffs produced neuronal depolarization in the center of the column-shaped region. However, both prior to or 30s after stimulation GABA puffs produced hyperpolarization of neurons. 2-photon imaging in neurons infected with adenovirus carrying a chloride sensor Clomeleon revealed that GABA induced depolarization is due to an increase in [Cl-]i after stimulation. To reveal the spatial extent of excitatory action of GABA, isoguvacine, a GABAA receptors agonist, was applied right after stimulation while monitoring the intracellular Ca2+ concentration in pyramidal neurons. Isoguvacine induced an increase in [Ca2+]i in pyramidal neurons especially in the center of the column but not in the peripheral regions of the column. The global pattern of the Ca2+ signal showed a column-shaped distribution along the stimulation site. Conclusion These results demonstrate that the well-known inhibitory transmitter GABA rapidly switches from hyperpolarization to depolarization upon synaptic activity in adult somatosensory cortical neurons.
Date of publication
Identifier
  • doi:10.1186/1756-6606-5-33
  • 23006518
Resource type
  • Article
Rights statement
  • In Copyright
Rights holder
  • Jaekwang Lee et al.; licensee BioMed Central Ltd.
License
Journal title
  • Molecular Brain
Journal volume
  • 5
Journal issue
  • 1
Page start
  • 33
Language
  • English
Is the article or chapter peer-reviewed?
  • Yes
ISSN
  • 1756-6606
Bibliographic citation
  • Molecular Brain. 2012 Sep 24;5(1):33
Access
  • Open Access
Publisher
  • BioMed Central Ltd
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