The M-Platform, a robotic device for motor rehabilitation after stroke in mice, has been upgraded to allow recording of neural activity during the pulling task (FIG 1). Now the platform provides the unique possibility to integrate kinetic and kinematic data with electrophysiological recordings in awake mice during a voluntary forelimb retraction task.
The new device was tested on four healthy mice: an array of 16 channels linear probe (ATLAS, USA) was inserted into the Rostral Forelimb Area (RFA) at 850 µm of depth. Signals were recorded by OmniPlex D System (Plexon, USA) at a frequency of 40 kHz (FIG 2). The analysis of the data was performed offline. We obtained promising results both for the low frequency activity, i.e. Local Field Potential (LFP), and for the high frequency activity, i.e. Multiunit Activity (MUA) and spike sorting. In particular in FIG. 3 a correspondence between the LFP and the force peak is evident; however we are planning to increase the number of recorded animals to generalize our results.
This success paves the way for investigation of neuroplastic events after a cortical damages, i.e. stroke. Moreover the possibility to record spiking activity in the Caudal Forelimb Area (CFA) during the task in healthy animals allows to study firing rate in different channels and find patterns to correlate neural activity and movement of the forelimb.