We present a new MEMS neural probe integrated with two microfluidic channels, a mixer, and biosensors for real-time monitoring of neurochemicals and neural activities. The microfluidic channels for push-pull operation of fluids enable infusion of drugs and extraction of brain fluid at the same time. Also, we can simultaneously monitor neural activities modulated by the infused drug. The real-time monitoring of neurochemicals using the monolithically integrated sensors is a new concept we propose which is enabled through the MEMS technology. The proposed system will provide an important new set of information for brain disease investigation and functional brain-mapping.