An apparatus for stimulating neurons, comprising - a stimulation unit implantable into a patient's body, said stimulation unit having at least one stimulation element for applying a stimulation signal to the patient's tissue in order to stimulate therewith neurons in the patient's brain and/or spinal cord, - a measurement unit for recording a measurement signal that represents a neuronal activity of the stimulated neurons, and - a control unit coupled with the stimulation unit and the measurement unit, which - creates a modulation signal from the measurement signal, - modulates the amplitude of a pulse train comprising a plurality of individual pulses with the modulation signal, and - controls the stimulation unit such that the at least one stimulation element applies the amplitude-modulated pulse train as the stimulation signal in order to stimulate therewith the neurons, wherein - each of the individual pulses comprises a first pulse portion and a second pulse portion following the first pulse portion, and - one of the first pulse portion and the second pulse portion imparts charge to the tissue and the other pulse portion takes charge from the tissue, characterized in that - a break is taken between each first pulse portion and each second pulse portion of the individual pulses, - the stimulation signal is configured to desynchronize an abnormally synchronous and oscillatory activity of the stimulated neurons when being applied to the patient, - the measurement signal represents the abnormally synchronous and oscillatory activity of the stimulated neurons, and - the control unit is configured to vary the break between the first pulse portion and the second pulse portion until synchronization of the stimulated neurons is at a minimum or falls below a predetermined threshold value. - a stimulation unit implantable into a patient's body, said stimulation unit having at least one stimulation element for applying a stimulation signal to the patient's tissue in order to stimulate therewith neurons in the patient's brain and/or spinal cord, - a measurement unit for recording a measurement signal that represents a neuronal activity of the stimulated neurons, and - a control unit coupled with the stimulation unit and the measurement unit, which - creates a modulation signal from the measurement signal, - modulates the amplitude of a pulse train comprising a plurality of individual pulses with the modulation signal, and - controls the stimulation unit such that the at least one stimulation element applies the amplitude-modulated pulse train as the stimulation signal in order to stimulate therewith the neurons, wherein - each of the individual pulses comprises a first pulse portion and a second pulse portion following the first pulse portion, and - one of the first pulse portion and the second pulse portion imparts charge to the tissue and the other pulse portion takes charge from the tissue, characterized in that - a break is taken between each first pulse portion and each second pulse portion of the individual pulses, - the stimulation signal is configured to desynchronize an abnormally synchronous and oscillatory activity of the stimulated neurons when being applied to the patient, - the measurement signal represents the abnormally synchronous and oscillatory activity of the stimulated neurons, and - the control unit is configured to vary the break between the first pulse portion and the second pulse portion until synchronization of the stimulated neurons is at a minimum or falls below a predetermined threshold value.