Study On Electrophysiological Characteristics Of Primary Visual Cortical Cells In Kainic Acid Model Mice

The balance between excitement and inhibition is the basis for the brain to maintain normal nerve electrical activity and achieve advanced cognitive functions.The occurrence of some neuropsychiatric diseases,such as epilepsy,Parkinson's disease,and depression,is thought to be related to the imbalance of brain excitement and inhibition,so study neurons The balance between excitement and inhibition has important theoretical value for understanding the processing of brain information.Glutamate is the main excitatory transmitter in the mammalian central nervous system,and glutamate receptor-dependent cells are widely distributed in the hippocampus and visual system.Kainic acid is a glutamic acid analog.Injecting kainic acid into the hippocampus can cause changes in the structure and function of the hippocampus,and even cause seizures.There is evidence that the hippocampus and the primary visual cortex have anatomical projections,and cell activity in the primary visual cortex is regulated by the hippocampus.Therefore,we speculate that the injection of kainic acid into the hippocampus may have an effect on the activity of primary visual cortical cells.In this study,we used mice injected with kainic acid in the hippocampus as the experimental group.The control group used physiological saline instead of kainic acid to record the peak potential and local field potential of neurons in the primary visual cortex of the mouse.The experiment tested the characteristics of receptive field size,peripheral inhibition,azimuth selectivity and contrast of primary visual cortical cells.The experimental results are as follows:(1)Compared with the control group,the primary visual cortical cells of the experimental group had a stronger spike potential when stimulated by the grating of the receptive field size.When the grating area is within the receptive field size and three times the receptive field size,the distribution of cell peak potential under different contrast stimulation is stronger than that in normal group mice.(2)There was no significant difference in the spontaneous emission of spike potential,peripheral inhibition index and orientation selectivity of primary visual cortical cells in the experimental and control mice.(3)Compared with the control group,the mice injected with kainic acid showed no significant difference in field potential energy between 0 and 100 Hz.Our research suggests that the injection of kainic acid in the hippocampus has no significant effect on the visual response characteristics of primary visual cortical cells,but it has a significant enhancement effect on the intensity of neuronal visual response.