Systems and methods are disclosed for local amplification, multiplexing and analog-to-digital conversion of signals sensed from deep brain regions. In one implementation, a system for local amplification, multiplexing and analog-to-digital conversion of signals sensed from deep brain regions comprises a neural probe configured for placement within a brain; at least one signal lead extending from the neural probe; a sensing assembly included on the neural probe including a plurality of electrodes, at least one amplifier configured to generate at least one amplification signal based on the sensed electrical signals generated by the neurons, and at least one multiplexer configured to multiplex at least two amplified signals based on the sensed electrical signals generated by neurons; and an externally located processing assembly with electrical components for analogue to digital conversion of signals, a signal generator, a power source, and electronic circuitry enabling wireless transfer of data and wireless charging of power.