An implantable device for the location-selective recording of neuronal electrical signals propagating along at least one nerve fibre contained in a nerve fibre bundle, as well as for the selective electrical stimulation of the at least one nerve fibre, comprising the following components: - implantable electrode arrangement which is arranged on a biocompatible carrier substrate which can be applied in a cuff-like manner around the nerve fibre bundle and which in the implanted state has, orientated towards the nerve fibre bundle, a straight cylindrical carrier substrate surface on which a first electrode arrangement for the location-selective recording of the neuronal electrical signals and selective electrical stimulation of the at least one nerve fibre, and on which a second electrode arrangement for recording an ECG signal are arranged, - an evaluation/control unit (A/S), which can be or is connected in an electrically conducting manner to the implantable electrode arrangement, in which the location-selectively recorded, neuronal, electrical signals as well as the ECG signal are evaluated in a time-resolved manner in such a way that a neuronal time signal correlated to a physiological parameter, preferably blood pressure, can be derived, - a first comparator unit, connected to the evaluation/control unit (A/S), in which a characteristic relative time offset between the ECG signal and neuronal time signal correlated with the physiological parameter can be determined, - a first function generator, connected to the evaluation/control unit (A/S), which within a time window determined by the evaluation/control unit (A/S) on the basis of the relative time offset generates a stimulation signal, adapted in terms of phase and time amplitude to the derived neuronal time signal correlated to the physiological parameter and composed of a plurality n of individual pulses as well as - a first signal-current converter which is directly or indirectly connected to the first function generator and the first electrode device and sends the stimulation signal for the selective electrical stimulation of the at least one nerve fibre to the first electrode device, wherein the evaluation/control unit (A/S), the first comparator unit, the first function generator as well as the first signal-current converter are combined as an implantable module. - implantable electrode arrangement which is arranged on a biocompatible carrier substrate which can be applied in a cuff-like manner around the nerve fibre bundle and which in the implanted state has, orientated towards the nerve fibre bundle, a straight cylindrical carrier substrate surface on which a first electrode arrangement for the location-selective recording of the neuronal electrical signals and selective electrical stimulation of the at least one nerve fibre, and on which a second electrode arrangement for recording an ECG signal are arranged, - an evaluation/control unit (A/S), which can be or is connected in an electrically conducting manner to the implantable electrode arrangement, in which the location-selectively recorded, neuronal, electrical signals as well as the ECG signal are evaluated in a time-resolved manner in such a way that a neuronal time signal correlated to a physiological parameter, preferably blood pressure, can be derived, - a first comparator unit, connected to the evaluation/control unit (A/S), in which a characteristic relative time offset between the ECG signal and neuronal time signal correlated with the physiological parameter can be determined, - a first function generator, connected to the evaluation/control unit (A/S), which within a time window determined by the evaluation/control unit (A/S) on the basis of the relative time offset generates a stimulation signal, adapted in terms of phase and time amplitude to the derived neuronal time signal correlated to the physiological parameter and composed of a plurality n of individual pulses as well as - a first signal-current converter which is directly or indirectly connected to the first function generator and the first electrode device and sends the stimulation signal for the selective electrical stimulation of the at least one nerve fibre to the first electrode device,