Comparison Of The Responsive Characteristics Between Interneuron And Pyramidal Cell In The Macaque Visual Posterior Sylvian Area(VPS) During Self-motion

People and higher animals need a variety of sensory cues to participate in their perception and judgment during self-motion.The most important cues are the optical flow information(visual cues)and the vestibular stimulation information caused by the head movement in space.Some researches showed that neurons in some cortical areas respond to optical flow and vestibular stimulation,but different regions have differences on preference and processing time of visual and vestibular reactions,suggests that different cortical areas may have different grade features in self-motion information encoding.It is found that some brain regions which are responsive to optical flow and vestibular stimulation,such as MSTd and VIP,had not effect on their self-motion perception based on vestibular stimulation after reversible deactivation,suggesting that their motion perception needs other brain regions.VPS neurons have visual and vestibular directional tuning,which mainly respond to vestibular cues,and the reaction time to the vestibular cue is earlier than to visual cues.However,previous studies didn't distinguish different neuronal types in different brain regions,so we can't understand the neural mechanisms underlying the encoding,processing and transmission of visual and vestibular stimuli in local neural networks.In this issue,neurons were classified according to the characteristics of the spikes: interneurons with narrow wavelength and pyramidal cells with wider wavelength.We examined spatial-temporal responses characteristics of pyramidal cells and interneurons in visual and vestibular stimulations,and tried to explore the mechanism of local neural networks in self-motion perception.The results showed that: 1)no matter in the condition of vestibular or visual stimulation,the pyramidal cell have significant stronger direction discrimination ability than the interneuron;2)the peaktime of pyramidal cell changes significantly between visual and vestibular condition,the peaktime of interneuron almost remainsunchanged at the same time;3)“Bimodel” pyramidal cell have significant stronger direction discrimination ability in vestibular condition than in visual condition;4)the peaktime of “Bimodel” pyramidal cell in vestibular condition was significantly earlier than thus in visual condition;5)“Bimodel” neurons have significant stronger direction discrimination ability than “unimodel” neurons.These results suggest that compare to interneuron,pyramidal cell is more sensitive,and more rapid to vestibular cues,the pyramidal cells in VPS area may carry the function of signal perception,analysis,and output.Interneuron may be involved in the establishment of the connections among the neurons and the synchronization of the activities of the local neuron circles.In order to explore the cognitive functional relationship between different neurons' activities in daily and spatial-temporal illusion adaption,we trained rhesus monkey heading discrimination task and multisensory adaptation task.Neuronal activity will be recorded soon.