Studies On Auditory-visual Multisensory And Auditory Perceptual Decision-making In Prefrontal Cortex PV Interneurons

Humans and animals obtain sensory information through a variety of peripheral sensory organs,and the brain can integrate this information to respond accurately and quickly to changes in the environment.Our previous research found that the prefrontal cortex(PFC)of mice is rich in auditory-visual multisensory neurons,and these neurons have the characteristics of multisensory integration.However,what is the difference between the way pyramidal neurons(PN)and PV interneurons(parvalbuminexpressing interneurons,PVIN)in the prefrontal cortex integrate multisensory information? No related research has been seen so far.Therefore,in the first part of this paper,PV-cre transgenic mice were used as experimental objects,combining optogenetics and multi-channel in vivo recording methods,using multi-channel optoelectrode and laser stimulation to accurately classify PV interneurons in mouse prefrontal cortex.While the animal is awake,record the response of prefrontal cortical neurons to auditory,visual and auditory-visual multisensory stimuli,and study the commonness and difference of integrated multisensory information of PV interneurons and pyramidal neurons in prefrontal cortex.Of the 852 neurons we recorded on 15 mice that responded to sensory stimulation,PV interneurons accounted for 8.8%(75/852)and pyramidal neurons accounted for 65.1%(555/852).A high proportion of PV interneurons(53.3%)and pyramidal neurons(46.1%)showed multisensory enhancement.Further analysis found that pyramidal neurons are more integrated than PV interneurons when the single-mode response is weak.When the single-mode response is strong,there is no difference in integration ability between pyramidal neurons and PV interneurons.This result suggests that when the single-mode response is weak,the stronger integration ability of pyramidal neurons will help the brain to complete the corresponding task of integrating multisensory information.In real life,pure passive perception is rare,and the vast majority of perceptions are related to behavioral tasks.Therefore,in the second part of this paper,we established the auditory decision-making task to study the similarities and differences between the discharge of PV interneurons and pyramidal neurons in the prefrontal cortex of animals when completing the perceptual decision-making task.It was found that when the mice learned the task and completed the task,both the PV interneurons and pyramidal neurons showed very strong selectivity for 3KHz and 12 KHz sound stimulation,and the selectivity of the two types of neurons was not obvious difference.However,when mice received passive sound stimulation before learning task,the two types of neurons responded similarly to 3KHz and 12 KHz sound stimulation,and there was no obvious difference.Further experiments found that during the learning task of mice,when the correct rate reached 60% and 70%,the selectivity of the two types of neurons showed a significant difference,and the selectivity of pyramidal neurons is stronger than PV interneurons.This result suggests that during the learning of auditory decision-making task,although the selectivity of PV interneurons and pyramidal neurons for both sounds gradually increases,pyramidal neurons increase faster.The research results of this paper found that,compared with interneurons,pyramidal neurons have stronger ability to integrate multisensory information and learn the task rules of perceptual decision-making faster.These results suggest that in the process of perception and cognition,pyramidal neurons and interneurons may play different roles.