TY - JOUR
T1 - Dynamic Recovery from Depression Enables Rate Encoding in Inhibitory Synapses
AU - Bridi, Morgan S.
AU - Shin, Sangyep
AU - Huang, Shiyong
AU - Kirkwood, Alfredo
N1 - Funding Information:
We thank Dr. H.-K. Lee for valuable discussions and comments and Dr. J. L. Whitt for help in viral injection. This work was supported by NIH grant R01EY012124 to A.K. and Hussman Foundation grant HIAS18001 to S.H.
Publisher Copyright:
© 2020 The Author(s)
PY - 2020/3/27
Y1 - 2020/3/27
N2 - Parvalbumin-expressing fast-spiking interneurons (PV-INs) control network firing and the gain of cortical response to sensory stimulation. Crucial for these functions, PV-INs can sustain high-frequency firing with no accommodation. However, PV-INs also exhibit short-term depression (STD) during sustained activation, largely due to the depletion of synaptic resources (vesicles). In most synapses the rate of replenishment of depleted vesicles is constant, determining an inverse relationship between depression levels and the activation rate, which theoretically, severely limits rate-coding capabilities. We examined STD of the PV-IN to pyramidal cell synapse in the mouse visual cortex and found that in these synapses the recovery from depression is not constant but increases linearly with the frequency of use. By combining modeling, dynamic clamp, and optogenetics, we demonstrated that this recovery enables PV-INs to reduce pyramidal cell firing in a linear manner, which theoretically is crucial for controlling the gain of cortical visual responses.
AB - Parvalbumin-expressing fast-spiking interneurons (PV-INs) control network firing and the gain of cortical response to sensory stimulation. Crucial for these functions, PV-INs can sustain high-frequency firing with no accommodation. However, PV-INs also exhibit short-term depression (STD) during sustained activation, largely due to the depletion of synaptic resources (vesicles). In most synapses the rate of replenishment of depleted vesicles is constant, determining an inverse relationship between depression levels and the activation rate, which theoretically, severely limits rate-coding capabilities. We examined STD of the PV-IN to pyramidal cell synapse in the mouse visual cortex and found that in these synapses the recovery from depression is not constant but increases linearly with the frequency of use. By combining modeling, dynamic clamp, and optogenetics, we demonstrated that this recovery enables PV-INs to reduce pyramidal cell firing in a linear manner, which theoretically is crucial for controlling the gain of cortical visual responses.
KW - Biological Sciences
KW - Cellular Neuroscience
KW - Mathematical Biosciences
KW - Molecular Neuroscience
KW - Neuroscience
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U2 - 10.1016/j.isci.2020.100940
DO - 10.1016/j.isci.2020.100940
M3 - Article
C2 - 32163896
AN - SCOPUS:85081025438
SN - 2589-0042
VL - 23
JO - iScience
JF - iScience
IS - 3
M1 - 100940
ER -