Figure 4.

Experimental and computational modeling evidence for recurrent, sequential activation of deep and superficial laminae during the beta1 population rhythm. (A) Example membrane potential changes in each neuron type temporally aligned to peak positivity in concurrently recorded field potentials. Lower graph shows pooled action potential distributions for IB (red), FS (green), RS (blue) and LTS (black) cells. Note IB and superficial layer FS neurons fire approximately one gamma period before RS and LTS cells in superficial layers. (B) (i) Cartoon representation of the computational model. The populations in both layers consist of twenty cells, although we only draw three of each cell type in the figure. The deep layer consists of IB cells of three compartments: D, the dendrite; S, the soma; and A, the axon. The superficial layer contains three cell types: RS cells (E), basket cells (I), LTS cells (LTS). Termination points of excitatory and inhibitory synapses are illustrated by red and blue circles, respectively. We connect all of the IB cell axons and RS cells with gap junctions (indicated by the red lines). (ii) The average cross-correlation between the spiking activity of the RS cell population and IB cell population. (iii) The spiking activity of the superficial layer cells (FS, RS and LTS cells) and layer V (IB cells). Each colored dot represents a spike in a single compartment. The horizontal line indicates 20 ms.