Recurrence Quantification Analysis of Spontaneous Electrophysiological Activity during Development: Characterization of In Vitro Neuronal Networks Cultured on Multi Electrode Array Chips
Figure 2
The mean firing rate (MFR) reports the average spike number during the investigation period (i.e., 10 minutes) and it is an indicator of the spontaneous neuronal activity. Random spiking activity can be recorded at a very early stage of the network development, that is, DIV 2 or 3. The network is still immature and spiking is slow, sporadic, and sparse (i.e., active channels are likely to be far and unsynchronized). After one week of in vitro culture (e.g., DIV10) it is possible to record more frequent activity. The network reaches its maturity at the third week in vitro when activity reaches its peak, and the maximum number of active channels is recorded (top right), and then it starts decreasing. Burst behavior appears during the second week of culture (bottom right). We monitored the network behavior up to DIV 42.
