Comparison Of Response Characteristics From Different Types Of MST Neurons During Self-motion Perception

Self-motion perception refers to the individual's need to perceive self-movement direction and self-movement state accurately when moving in a complex environment.The completion of this process requires the participation of multiple sensory information,in which vestibular information and visual information play an important role.The neurons in the Medial Superior Temporal area(MST)of macaques have strong directional selectivity for vestibular information and visual information.This brain area is important for studying self-motion perception.The study of the type of neurons in area MST and the response characteristics of different types of neurons in self-motion perception is of great significance for understanding the information transmission mechanism of the neural circuits in self-motion perception.In this study,single-electrode recording technique was used to record the response of neurons in area MST of macaques under vestibular,visual and combined conditions.A total of 324 neurons were recorded in area MST of two monkeys.Waveform duration and spontaneous firing rate(SponT)were selected as the classification indicators.Using k-means cluster analysis,neurons of area MST were divided into interneurons(N = 57),pyramidal neurons(N = 94)and other neurons(N = 173).The response characteristics of different types of neurons were quantified by multiple indicators,such as firing rate,half-tuning width,preferred direction,direction discrimination index(DDI)and peak time.The results showed that:(1)Under the vestibular condition,the firing rate was significantly higher among interneurons than pyramidal neurons in area MST;Under the visual condition,interneurons have higher firing rate,larger half tuning width,stronger direction discrimination index and earlier peak time than pyramidal neurons in area MST.(2)Under the visual condition,the direction discrimination index was significantly stronger among other neurons than pyramidal neurons,and there was no significant difference compared with interneurons;the half tuning width was significantly smaller among other neurons than interneurons,and there was no significant difference compared with pyramidal neurons.(3)Comparing the difference in response characteristics of neurons between area VPS and area MST in self-motion perception,and we find that the temporal modulation tuning characteristics of interneurons was significantly different compared with pyramidal neurons in area MST under visual condition;the temporal modulation tuning characteristics of interneurons was significantly different compared with pyramidal neurons in area VPS under vestibular condition.The results showed that there are significant differences in the response characteristics among interneurons than pyramidal neurons in macaque area MST during self-motion perception,suggesting that the two types of neurons play different roles in self-motion perception.Therefore,the research is fundamental for understanding the information transmission mechanism of neural circuits in self-motion perception.