The Modeling Of Neuronal Information Encoding In Primary Auditory Cortex

Primary auditory cortex(Al)is the advanced core of the brain’s processing of external auditory information and plays an important role in mammalian natural survival.Existing research indicates that A1 has a rich anatomical structure composed of excitatory pyramidal neurons(Pyr)and a variety of intermediate inhibitory neurons such as parvalbumin neurons(PV)and somatostatin neurons(SOM),forming a complex neuron network inside the cortex to process and transmit auditory information,but the sound processing process by A1 neurons remains unknown.Therefore,it is of great significance to explore the principle of neuronal information coding in the auditory nervous system of the brain.In this study,we employed A1 auditory neurons to investigate the electrophysiological cell attachment recording,population neuron modeling,and the coding features of Al neurons.First,using cell-attached recording,we carried out extensive electrophysiological recordings of A1 neurons.Then,we analyzed the auditory response properties of A1 auditory neurons,and the results revealed that A1 neurons have significant characteristics of diversity of response patterns to sound stimuli,including Onset responses,Sustained responses,Offset responses,and On-off responses.A1 neurons are thought to realize the processing,processing,and transmission of auditory information through the joint coding of various emission modes.There are also a few suppression responses,such as full inhibition response and semi-inhibitory response,and these responses’ coding characteristics vary.Then,using neuronal population modeling technology,we build the Pyr-PV-SOM neuronal population model of A1 to investigate the role of different types of neurons in the auditory information processing process.The results show that Pyr,SOM,and PV neurons produce different degrees of response activity to the same sound input,and the peak and response duration of neuronal response are different.When the model’s input is a repeating sound stimulus,it is obvious that the responses of different neural groups exhibit stimulus adaption features.Through simulations of trials involving the optogenetic activation and inhibition of PV and SOM,we discovered that when PV is activated,it may greatly reduce Pyr response activity,and when PV is inhibited,Pyr response activity is significantly amplified.PV and SOM have distinct degrees of influence on Pyr,and there is a current compensation effect between the two,showing that PV and SOM have separate functional roles in auditory information processing in the cortex.Finally,we investigated the synaptic time constants of excitation and inhibition of neurons in the model and found that the time constant has a significant influence on neuronal response patterns,which may be related to the rapid excitatory current and slow delayed synaptic inhibition that are widely distributed in the cortex.This discovery led us to simulate the auditory response mode of A1 neurons.The correlation between the simulated neuronal response and the actual recorded A1 neuron response was strong,indicating that the model constructed in this study has some degree of rationality,which can characterize the fundamentals of A1 neuron information processing and transmission in the auditory system and offer fresh concepts for further elucidating the A1 information encoding process.