An integrated neuronal amplifier for amplifying neuronal signals, comprising: (a) a first stage amplifier within the neuronal amplifier, said first stage amplifier being configured for connection to a working electrode and a counter electrode, each said electrode being connected to said first stage amplifier through a DC blocking capacitor (Cin), as input capacitor； (b) a capacitive feedback circuit within the first stage amplifier configured to establish a gain of said neuronal amplifier as a ratio of the input capacitor (Cin) and the feedback capacitor (Cf)； and (c) a "folded-helmet" (FC) amplifier having an auxiliary gain stage incorporated in said first stage amplifier to increase the open loop gain, said auxiliary gain stage comprising two common source amplifiers (CS) , wherein said common source amplifier (CS) is formed by a differential pair of transistors with diode connected load, so that the differential outputs of said first common source amplifier (CS) are connected to two transistor doors of the current source of said "folded-helmet" amplifier comprising the second common source amplifier (CS) embedded in the folded branch of said "folded-helmet" (FC) amplifier in order to minimize current consumption.Un amplificador neuronal integrado para amplificar señales neuronales , que comprende: (a) un primer amplificador de etapa dentro del amplificador neuronal, estando dicho primer amplificador de etapa configurado para la conexión a un electrodo de trabajo y a un electrodo contador, estando cada dicho electrodo conectado a dicho primer amplificador de etapa a través de un condensador de bloqueo DC (Cin), como condensador de entrada； (b) un circuito de retroalimentación capacitivo dentro del primer amplificador de etapa configurado para establecer una ganancia de dicho amplificador neuronal como una relación del condensador de entrada (Cin) y el condensador de retroalimentación (Cf)； y (c) un amplificador "folded-cascode" (FC) que tiene una etapa de ganancia
