TY - JOUR
T1 - Brief dark exposure reduces tonic inhibition in visual cortex
AU - Huang, Shiyong
AU - Hokenson, Kristen
AU - Bandyopadhyay, Sabita
AU - Russek, Shelley J.
AU - Kirkwood, Alfredo
N1 - Publisher Copyright:
©2015 the authors.
PY - 2015/12/2
Y1 - 2015/12/2
N2 - Tonic inhibition mediated by extrasynaptic GABAA receptors (GABARs) sensing ambient levels of GABA can profoundly alter the membrane input resistance to affect cellular excitability. Therefore, regulation of tonic inhibition is an attractive mechanism to control the levels of cortical firing. In cortical pyramidal cells, tonic inhibition is regulated by age and several neurotransmitters and is affected by stroke and epilepsy. However, the possible role of sensory experience has not been examined. Here, we report that a brief 2-day exposure to dark reduces by 1/3 the inhibitory tonic conductance recorded in layer II/III pyramidal cells of the mouse juvenile (postnatal day 12-27) visual cortex. In these cells, tonic inhibition is carried primarily by GABARs containing the δ subunit. Consistently, the dark exposure reduction in conductance was associated with a reduction in δ subunit levels, which were not affected in control frontal cortex. We propose that a deprivation-induced reduction in tonic inhibition might serve a homeostatic function by increasing the firing levels of cells in deprived cortical circuits.
AB - Tonic inhibition mediated by extrasynaptic GABAA receptors (GABARs) sensing ambient levels of GABA can profoundly alter the membrane input resistance to affect cellular excitability. Therefore, regulation of tonic inhibition is an attractive mechanism to control the levels of cortical firing. In cortical pyramidal cells, tonic inhibition is regulated by age and several neurotransmitters and is affected by stroke and epilepsy. However, the possible role of sensory experience has not been examined. Here, we report that a brief 2-day exposure to dark reduces by 1/3 the inhibitory tonic conductance recorded in layer II/III pyramidal cells of the mouse juvenile (postnatal day 12-27) visual cortex. In these cells, tonic inhibition is carried primarily by GABARs containing the δ subunit. Consistently, the dark exposure reduction in conductance was associated with a reduction in δ subunit levels, which were not affected in control frontal cortex. We propose that a deprivation-induced reduction in tonic inhibition might serve a homeostatic function by increasing the firing levels of cells in deprived cortical circuits.
KW - Extrasynaptic receptors
KW - Layer 2/3
KW - Pyramidal cells
KW - δ-GABA receptor
UR - http://www.scopus.com/inward/record.url?scp=84949432131&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84949432131&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.1813-15.2015
DO - 10.1523/JNEUROSCI.1813-15.2015
M3 - Article
C2 - 26631472
AN - SCOPUS:84949432131
VL - 35
SP - 15916
EP - 15920
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 48
ER -