Preliminary Study On Design And Experiment Of Electric Field Stimulator For Small Animals

Cognitive impairment is known as cognitive decline,or cognitive disability,that is,one or more cognitive functions such as learning and memory,performing calculation or understanding and judgment are damaged,resulting in various degrees of cognitive impairment from mild cognitive impairment to dementia.Traditional treatment schemes have some limitations,and the impact of electric field stimulation on cognitive behavior has gradually attracted researchers’ attention.Electric field can directly affect the tissue structure and function of some nervous systems.In the process of animal experiments,it is difficult to directly measure the electric field intensity in the brain.Therefore,this paper establishes an electric field model through finite element simulation to explore the distribution of intracranial electric field during electric field stimulation.The simulation results show that the skull layer absorbs the maximum external electric field and the cerebrospinal fluid layer absorbs the minimum external electric field,and the electric field utilization rate of hippocampus is about 6.1%.Combined with the electric field intensity range of biological effects in hippocampus,the maximum value of micro electric field stimulation parameters studied in this paper is determined to be 160 k V/m,which provides a design basis for the subsequent development of electric field stimulator parameters.Ensure that the electric field parameters of animal experiments are within the safe range and can stimulate the target area of hippocampus to cause biological effects.An electric field stimulator suitable for animal experiments is designed.The electric field stimulator meets the requirements that the electric field intensity is 0～160k V/m and the frequency is adjustable at 10～40Hz.It can greatly reduce the cost of animal experimental research due to its simple structure and function and easy to be replicated.According to the relevant principles and the research and development workflow of the stimulator,the specific design index requirements of the device,the overall design scheme is put forward,and the specific design,installation,commissioning and index test of each unit circuit are carried out,which provides a more practical experimental device for exploring the effect of electric field stimulation on the cognition of experimental mice.Taking mice as the research object,this paper preliminarily completed the study on the cognitive effect of micro electric field stimulation on mice.Firstly,the basic physiological parameters of body temperature,body weight and exercise ability of normal C57 mice were detected.It was found that there was no difference in physiological indexes between the mice and the control group after different intensities of micro electric field stimulation,so as to verify the safety of micro electric field stimulation.Secondly,two different doses of LPS were selected for a single intraperitoneal injection.The results showed that within a certain time range,the cognitive impairment model caused by intraperitoneal injection of high-dose LPS was more stable than that of low-dose LPS.The feasibility and effectiveness of establishing cognitive impairment mouse model by intraperitoneal injection of 2mg/kg LPS were verified.Finally,the experiment of the effect of micro electric field stimulation on cognitive impairment model mice was designed,whether it is behavioral detection,immunohistochemistry and immunofluorescence experiment,it is concluded that160 k V/m micro electric field stimulation can improve the spatial exploration and recognition memory ability of experimental mice,and improve the cognitive impairment(neuronal apoptosis and inflammatory response)induced by intraperitoneal injection of 2mg/kg LPS.