Monitoring assembly which is suitable for being able to intraoperatively stimulate functions controlled by the nervous system and has at least one probe (1, 4) which can be inserted into a body, wherein - the first probe is coupled to at least a first light source, which is connected to control apparatus coupled to an evaluation apparatus, or to a sound source, wherein a stimulation signal in the form of radiation suitable for distinguishing neuronal tissue from non-neuronal tissue can be generated using the light source or the sound source, wherein the control and evaluation apparatus (9, 10) associated with the first probe is connected to a first sensor for detecting reflected light radiation by means of an optical fiber or to sound detection means for detecting reflected sound signals, wherein the control and evaluation apparatus (9, 10) is designed to distinguish between neuronal and non-neuronal tissue on the basis of the reflected signals detected by the first sensor, wherein the first sensor having the associated evaluation apparatus comprises a temperature measurement and temperature monitoring function which acts in a regulating manner on the control apparatus and thus on the emitted radiation, and - a second probe is designed to detect a stimulation response of a target organ, wherein the second probe comprises at least one EMG derivation electrode or is designed to detect a pressure signal or comprises at least one optical fiber which is connected to a second light source, wherein the second light source for emitting light radiation in the infrared wavelength range is connected to a control apparatus which is in turn coupled to an evaluation apparatus connected to a second sensor, - wherein the two probes (3, 4) are connected to a monitoring computer of the monitoring assembly via their associated control apparatus (9, 13) and evaluation apparatus (10, 14). - the first probe is coupled to at least a first light source, which is connected to control apparatus coupled to an evaluation apparatus, or to a sound source, wherein a stimulation signal in the form of radiation suitable for distinguishing neuronal tissue from non-neuronal tissue can be generated using the light source or the sound source, wherein the control and evaluation apparatus (9, 10) associated with the first probe is connected to a first sensor for detecting reflected light radiation by means of an optical fiber or to sound detection means for detecting reflected sound signals, wherein the control and evaluation apparatus (9, 10) is designed to distinguish between neuronal and non-neuronal tissue on the basis of the reflected signals detected by the first sensor, wherein the first sensor having the associated evaluation apparatus comprises a temperature measurement and temperature monitoring function which acts in a regulating manner on the control apparatus and thus on the emitted radiation, and - a second probe is designed to detect a stimulation response of a target organ, wherein the second probe comprises at least one EMG derivation electrode or is designed to detect a pressure signal or comprises at least one optical fiber which is connected to a second light source, wherein the second light source for emitting light radiation in the infrared wavelength range is connected to a control apparatus which is in turn coupled to an evaluation apparatus connected to a second sensor, - wherein the two probes (3, 4) are connected to a monitoring computer of the monitoring assembly via their associated control apparatus (9, 13) and evaluation apparatus (10, 14).