Exploration Of Attention Regulatroty Nucleus And Related Mechanism In Mouse

Attention is key to high-level cognition,and attention deficits are considered a hallmark of cognitive dysfunction.There are many disorders associated with attention deficiency-related disease,such as attention deficit hyperactivity disorder(ADHD),autism spectrum disorder(ASD)and bipolar disorder(BP),etc.In the existing research reports,it is suggested that some brain regions and circuits are involved in the regulation of attention,for example,the hippocampus plays a vital role in regulating cognitive functions.In this study,the mouse 5-choice serial reaction time task(5-CSRTT)was constructed,and the activated neurons were screened out by immunofluorescence staining,and then the neurobiological mechanism of brain regions and circuits was explored by means of in vivo fiber photometry and chemogenetic techniques.According to the results of immunofluorescence staining and the current research reports,we located the target brain regions in the Insular Cortex and PVT-LSv circuit.In order to reveal the neurobiological mechanism of the insular cortex and the PVTLSv circuit involved in attention.Objective:This study intends to explore the nuclei related to the regulation of attention behavior by constructed a stable and reliable rodent attention model,and dig out new nuclei and new circuits related to attention that have not been reported in the model.The neurobiological mechanism of new nuclei and new circuits participating in attention is also explored through in vivo fiber photometry and chemogenetic techniques.In order to provide experimental basis for in-depth research on the neural mechanism of attention and the discovery of new targets for the treatment of attention deficiencyrelated disease.Methods:1.In the study of the function of the insular involved in 5-CSRTT attention behavior,we perfused the brains of C57BL/6 male mice that completed the 5-CSRTT behavioral paradigm,then frozen the tissue sections,and performed immunofluorescence staining on the brain sections.Cell colocalization,determining cell subtypes in the insular(glutamatergic neurons).Then the cannula was embedded into the mouse insular target position through a stereotaxic instrument,and the instantaneous activity of calcium signals in neurons of the mouse was recorded during the attention behavior.In addition,chemogenetic regulation methods were selected to observe the influence of insular glutamatergic neurons on attention,and the behavioral changes of mice were observed through chemogenetic inhibition and chemogenetic activation of insular glutamatergic neurons.2.In the functional study to explore the participation of PVT-LSv circuit in 5-CSRTT attention behavior,similar to method 1,the mice that completed 5-CSRTT were also perfused,sectioned,and immunofluorescent stained.Then inject forward tracer virus in PVT,inject retrograde tracer virus in LSv brain region,and determine the projection relationship between the two brain regions.Then,the calcium response mode of PVTLSv circuit was recorded in response to attention behavior by means of in vivo fiber photometry.Results:1.In the study of the insular cortex,the results of immunofluorescence staining showed that after the mice completed the 5-CSRTT behavior,compared with the control mice,anterior insular(aIC),medial insular(mIC),posterior insular(pIC),c-Fos were activated in brain regions,and more neurons were activated in aIC than in mIC and pIC,and c-Fos neurons activated in aIC were mainly glutamatergic neurons.In the results of in vivo fiber photometry,when the mice responded to the attention behavior,calcium signals were significantly higher than those in the other three groups of behavioral indicators,indicating that aIC glutamatergic neurons responded to the mouse attention behavior.In addition,when chemogenetic inhibition of aIC glutamatergic neurons,the accuracy of mice became lower compared with controls.Conversely,when aIC glutamatergic neurons were chemogenetic activated,mice were more accuracy.The results suggest that aIC glutamatergic neurons may bidirectionally regulate mouse attention behavior.2.In the study of the PVT-LSv circuit part,c-Fos in the PVT brain area and LSv brain area of mice was significantly activated compared with the control group after the mice completed behavioral studies.Anterograde tracing results showed that LSv received projections from PVT;similarly,retrograde tracing results showed that LSv axon terminals received projections from PVT.In vivo fiber photometry showed that PVTLSv circuit neurons responded to attention behavior,and the calcium activity was higher than that of the other three behaviors.Conclusion:1.After mice completed the 5-CSRTT attention model,c-Fos in aIC,mIC,and pIC were significantly activated compared with the control,and the activated neurons in aIC were mainly glutamatergic neurons.Calcium signals were significantly elevated in mice in response to attentional behavior.And chemogenetic inhibition of insular glutamatergic neurons in mice impairs attentional behavior,and chemogenetic activation of insular glutamatergic neurons in mice enhances attentional behavior.This study suggests that insular glutamatergic neurons are involved in the attention process.2.After mice performed 5-CSRTT behavior,c-Fos neurons in the PVT and LSv brain regions were correspondingly activated.And the calcium activity of neurons in the PVT-LSv circuit was significantly increased when the mice responded to the attention behavior.