Effects Of Inhibition Of TrkB Receptor Expression In PV Interneurons On The Function And Visual Orientation

The excitatory-inhibitory balance system of the cortex maintains normal physiological functions of the brain and is critical to cortical function shaping,healthy cognition and behavior,and can dynamically regulate neuronal responses to visual stimuli.It has been found that the interaction of neurotrophic factors BDNF and NT-3 with their specific tyrosine receptor kinase B(TrkB)can mediate the balance regulation of cortical excitability,which is also important for the development of the cortical inhibitory system and visual function.The visual cortex is one of the most studied experimental models for analyzing the functional and structural processes of the cerebral cortex,and TrkB signaling plays an important role in regulating the response strength of primary visual cortex(V1)neurons and the function of cortical networks.It was found that TrkB signaling plays an important role in regulating the function of excitatory and inhibitory neurons,affecting the response strength and response properties of neurons,and that reduced expression levels of TrkB in V1 may lead to the weakening of the GABAergic inhibitory system and changes in the response properties of neurons,while the decline of the cortical TrkB signaling pathway due to aging has also been shown to be associated with the decline of the GABAergic inhibitory system.The decline of cortical TrkB signaling pathway due to aging has also been shown to be associated with the decline of GABAergic inhibitory system.To further investigate how TrkB receptors in the PV interneurons of V1 regulate visual information processing,we constructed a Cre-dependent adeno-associated virus that expresses shRNAs that selectively bind to the Ntrk2 motif structure of Cre+ neurons,affecting their transcriptional generation of the TrkB receptor.In this experiment,we injected the virus into the primary visual cortex of PV Cre mice to reduce the expression level of TrkB receptors on PV neurons in V1,and recorded the activity of primary visual cortex neurons by in vivo multichannel electrophysiological means and tested the orientation discrimination ability of mice by behavioral experiments.The results show that inhibition of TrkB signaling in PV neurons in primary visual cortex modulates the response properties of inhibitory interneurons and excitatory neurons,causes a decline in the receptive field characteristics of cortical neurons,and induces an increase in response variability and coding fidelity.The findings demonstrate that weakening of the TrkB signaling pathway in PV neurons in primary visual cortex can cause functional changes in mouse brain regions,resulting in impaired orientation discrimination in mice,that intact TrkB signaling plays an important role in the primary visual cortex and in the processing of visual information at the individual level,and that PV inhibitory interneurons in the cortex are necessary for the functioning of this signaling pathway.The process is necessary for the functioning of this signaling pathway,providing a new perspective and target of action for the treatment of vision-related diseases.