Bayesian method and dynamic clamp technique to measure neural phase-response curves

Neuronal circuits are constructed by neurons and synapses, and neural signals are processed based on the wiring diagram of neuronal circuits. Thus, it is important to determine the relationship between the structure (neuronal wiring diagram) and the function (signal processing) of neuronal circuits. To address this issue, we developed hybrid neuronal circuits where artificial synapses are incorporated into biological neuronal circuits. In this hybrid neuronal circuit, simultaneous patch–clamp recording and singlefiber stimulation were made from multiple neurons in brain slices, and the recording/stimulation were also combined with artificial synapses using a dynamic clamp technique. An advantage of the hybrid neuronal circuit is that researchers can manipulate the wiring diagram of neuronal circuits as they like, so that they can investigate signal processing in anatomically defined neuronal circuits. In this study, we investigated an anatomically defined circuit from the thalamus to the neocortex, and found that the thalamocortical circuit exhibits three types of synaptic integrations. We further found that these three functional operations are switched by different neuromodulators (norepinephrine and adenosine). These results show that multiple types of signal processing modes co-exist in a single neuronal circuit.