Neurological Mechanism Of Working Memory Impairment Caused By Aging

Working memory is one of the basic functions of the brain,which can store information for a short time.Previous studies in our group found that some neurons in prefrontal cortex of normal adult mice maintained high discharges during the delayed period of task,which may be related to working memory.Aging can lead to the decline of working memory ability.However,what changes have taken place in the prefrontal cortex neurons of aged mice when they complete the task of working memory? We don’t know yet.In order to answer this question,we used the aged C57BL/6 mice(more than 18 months)as the model,and recorded the electrical activity of prefrontal cortex neurons while the animals completed the auditory working memory task by embedding multi-electrode recordings in vitro.We analyzed the firing responses of various types of neurons and compared them with normal adult mice.Our results showed that delayed excitatory neurons still existed in the prefrontal cortex of the aged animals when they completed the task,but the proportion of neurons involved in the task and delayed excitatory neurons were significantly lower than that of the normal adult animals.At the same time,population neuron analysis showed that the firing response of excitatory neurons in delayed prefrontal cortex of aged mice was significantly lower than that of normal adult animals,and the ability of neurons to distinguish two sounds was also significantly reduced.Another group of aged mice who completed the task of visual working memory also obtained similar results,that is,the discharge response of excitatory neurons in delayed prefrontal cortex of aged mice was significantly lower than that of normal adult mice,and the ability of neurons to distinguish light in two directions was also significantly reduced.This study will help us understand the neurological basis of the decline in working memory during aging.