Scientists have found that excitement in the visual cortex loop - inhibits the rhythmic oscillation of balance.

He Kaiwen, a researcher at the interdisciplinary research center of biology and chemistry, Shanghai Institute of organic chemistry, Chinese Academy of Sciences, and Alfredo Kirkwood team of Johns Hopkins University for the first time found that the balance between excitation and inhibition (E / I balance) of neurons showed rhythmic oscillation in the circadian cycle.through further research, it was found that the oscillation was specific to the neural circuit and closely regulated by sleep / wakefulness experience. Endogenous cannabinoid in the brain is the key molecule to mediate the regulation.the research paper entitled "daily operations of the exception inhibition balance in visual cortical circuits" was published in the academic journal Neuron on December 9.Michelle bridi of Johns Hopkins University and Zong fangjiao, center of biology and chemistry, Shanghai Institute of organic chemistry, Chinese Academy of Sciences, are co authors, and he Kaiwen and Alfredo Kirkwood are co authors.the processing and transmission of information by neurons depend on excitatory synapses such as glutamatergic acid to transmit nerve signals, and gamma aminobutyric acid (GABA) can restrict the signal transmission in time and space.just as the combination of throttle and brake determines whether the vehicle can drive safely and correctly, the balance between neuron excitation and inhibition (E / I balance) is the key factor determining the function of neurons and neural networks, which can affect the social behavior and sensory perception performance of animals.at the same time, a large number of studies have found that E / I balance is also closely related to various nervous system diseases.therefore, understanding the regulatory mechanism of E / I balance is very important for understanding the regulation of brain function and related brain diseases.on the regulation of neuron E / I balance, the current mainstream view is that neurons can maintain the stability of E / I balance through rapid plasticity regulation mechanism, so as to ensure the normal function of neurons.however, just like cars in different driving scenarios, such as highways vs urban main roads, the proportion of accelerator and brake is obviously different. The brain experiences different physiological states in a day, and its information processing needs are not consistent.in the above work, researchers have revealed a new regulation mode and possible mechanism of E / I balance, and found that there is a slow periodic regulation mechanism of E / I balance in daytime and nighttime neurons, which can greatly change the fixed value of E / I balance in different periods.this does not contradict the current known dependence on plasticity to rapidly stabilize the E / I balance. The former can only be achieved in a few hours after the day night transition, while the latter occurs in a few minutes or even less.the researchers believe that the E / I balance will be stable for the rest of the same cycle after reaching the new set value, which may be due to the adoption of plasticity regulation mechanism.the above work is supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China.Fig. 1 the charge oscillation of SIPSC is modulated by sleep and CBR signal in light / dark period. Fig. 2 specific modulation source of E / I ratio: Shanghai Institute of organic chemistry, Chinese Academy of Sciences