Figure 13.

Proposed model of differences of synaptic input and response properties between auditory layer 5 and layer 6 corticothalamic neurons. In our model, layer 5 corticothalamic neurons receive excitatory input from neurons in layers 2/3, 4, and 5 (gray) and GABA_A-mediated inhibitory input mostly from lower layer 5 with a smaller contribution from layer 2/3 (red). In response to excitatory input, these neurons fire a burst of action potentials at low threshold. In contrast, layer 6 corticothalamic neurons integrate excitatory input primarily from layer 6 and receive inhibitory input from adjacent areas in layer 6. In response to excitatory input, these neurons fire a train of individual action potentials.