Daily Oscillation of the Excitation-Inhibition Balance in Visual Cortical Circuits

Neuron. 2020 Feb 19;105(4):621-629.e4. doi: 10.1016/j.neuron.2019.11.011. Epub 2019 Dec 9.


A balance between synaptic excitation and inhibition (E/I balance) maintained within a narrow window is widely regarded to be crucial for cortical processing. In line with this idea, the E/I balance is reportedly comparable across neighboring neurons, behavioral states, and developmental stages and altered in many neurological disorders. Motivated by these ideas, we examined whether synaptic inhibition changes over the 24-h day to compensate for the well-documented sleep-dependent changes in synaptic excitation. We found that, in pyramidal cells of visual and prefrontal cortices and hippocampal CA1, synaptic inhibition also changes over the 24-h light/dark cycle but, surprisingly, in the opposite direction of synaptic excitation. Inhibition is upregulated in the visual cortex during the light phase in a sleep-dependent manner. In the visual cortex, these changes in the E/I balance occurred in feedback, but not feedforward, circuits. These observations open new and interesting questions on the function and regulation of the E/I balance.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Circadian Rhythm / physiology*
  • Excitatory Postsynaptic Potentials / physiology*
  • Female
  • Inhibitory Postsynaptic Potentials / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Nerve Net / cytology
  • Nerve Net / physiology*
  • Neural Inhibition / physiology
  • Organ Culture Techniques
  • Pyramidal Cells / physiology
  • Visual Cortex / cytology
  • Visual Cortex / physiology*
  • Visual Pathways / cytology
  • Visual Pathways / physiology*