The self-development mechanism of somatostatin-positive intermediate neurons in the motor cortex M2 was clarified.

On December 7th, Wang Xiaoqun of the Institute of Biophysics of the Chinese Academy of Sciences published online in the international journal Cerebral Cortex, an online study entitled Eby Excita Activity-Dependent Maturation of Somatostatin Interthes in The Soktical Layer 2/3 of Mice, which illustrates the important time-frame for the development of somatostatin (SST- positive) in the m2 of the motor cortex.
the cerebral cortex as the central nervous system that regulates the movement and thinking of organisms, with complex cellular composition and loop connections.
in the cerebral cortex, about 20% of the neurons are GABA-energy intermediate neurons, which can be divided into subcategories according to their morphology and physiological characteristics, which function differently and bind together to precisely regulate the complex activities of neural networks.
the early appearance of SST-positive intermediate neurons, before the emergence of rapid release (fast-spiking) type intermediate neurons, for the establishment and development of local neural networks played a crucial role, but the current reports do not give a clear conclusion on the SST intermediate neurons themselves mature characteristics and their early developmental regulatory mechanisms. For the first time in
, researchers systematically collected the electrophysiological and morphological characteristics of the sST intermediate neurons in the sST layer in the second-third layer of the cerebral cortex between the first day and 30th of life, and based on these data analysis found that the first two weeks of life were a critical period of sST intermediate neuron development, during which time the neurons matured rapidly and their own electrophysiological parameters stabilized after the 15th day of life.
the researchers also used the two-channel diaphragm clamp technology to detect chemical synaptic contacts between SST intermediate neurons and nearby cone cells, and found that these synaptic connections also increased with the development process.
later to find out whether these inputs from other cells had an effect on the development of SST-positive intermediate neurons, the researchers used toxin injections into the cortex to interfere with synaptic transmission at different times, and for the first time found that after interfering with synaptic transmission on the first day of life, the sST intermediate neurons had significantly lagged behind their development, while interference on the 8th day did not affect the maturation of these intermediate neurons.
To further explain which neurons' synaptic connections led to this phenomenon, the researchers used embryonic electrotransfer technology to be able to suppress neuronal excitability in the Kir2.1 channel, which is only expressed in mouse dermal vertebral cells.
results show that when the cone cell's excitability decreases, the self-maturation of the sST intermediate neurons lags significantly, with the delay effect lasting at least one month after birth.
based on the above study, the researchers first reported and suggested that the maturation of the SST intermediate neurons themselves was closely related to the dominant intensity and tempo of cone cells.
this new conclusion perfects the unique mature characteristics and regulatory mechanisms of SST intermediate neurons in the process of cortex development, and the results and ideas will provide new ideas and theoretical basis for the study of the development of local neural networks in the cortex, intra-loop excitatory-inhibition balance, and so on.
the work was completed independently by Wang Xiaoqun's task group.
Wang Xiaoqun is the communication author of this article, and Pan Na, assistant researcher of the research group, and Fang Ai, Ph.D., are the first authors of this article.
the research was supported by projects from the Ministry of Science and Technology, the Natural Science Foundation of China and the Chinese Academy of Sciences.
Source: Institute of Biophysics.