We present a high density CMOS neural probe with active electrodes (pixels), consisting of dedicated in-situ circuits for signal source amplification. The complete probe contains 1356 neuron sized (20×20 µm2) pixels densely packed on a 50 µm thick, 100 µm wide and 8 mm long shank. It allows simultaneous high-performance recording from 678 electrodes and a possibility to simultaneously observe all of the 1356 electrodes with increased noise. This considerably surpasses the state of the art active neural probes in electrode count and flexibility. The measured action potential band noise is 12.4 µVrms, with just 3 µW power dissipation per electrode amplifier and 45 µW per channel (including data transmission).