Effect of Transcranial Ultrasonic-Magnetic Stimulation on Two Types of Neural Firing Behaviors in Modified Izhikevich Model

Non-invasive brain neuromodulation is indispensable to the study of brain function. It has also been proven effective for treating some neurological disorders. As a novel method for brain neuromodulation, transcranial ultrasonic-magnetic stimulation (TUMS) does not need surgery and genetic alteration, it also owns higher spatial resolution and deeper penetration than other non-invasive methods such as transcranial direct current stimulation and transcranial magnetic stimulation. It has not been explored before although the intramembrane mechanoelectrical effect plays an important role in the firing activity of neuron. Membrane capacitance of neuron changes under the function of ultrasonic radiation force. In this paper, we modified the Izhikevich model, and neuron firing behaviors based on this model under both ultrasonic-magnetic effect and mechanoelectrical effect of TUMS are studied. How TUMS modulates neural firing activity was shown. The simulation experiment showed that parameter values of TUMS determine the current density, resulting in different firing behaviors. Compared with ultrasonic-magnetic effect alone, combining ultrasonic-magnetic and mechanoelectrical effects of TUMS together result in different neuron firing patterns. Our results further highlight the role of both electromechanics and ultrasonic-magnetic effects in neural excitation. They help illuminate sub-threshold and novel physical cellular effects, and may be useful in finding better methods for neural control.