Figure 3.

Barrel cortex plasticity. (A) Local circuit changes in barrel cortex following whisker deprivation. Shown are layer 4 (L4) and layer 2/3 (L2/3) cells and their excitatory synaptic connections. The size of the receptors indicates the strength of the synapse. Yellow shading indicates cells driven by the deprived barrel and green shading indicates cells driven by the non-deprived barrel. Reducing sensory input to one barrel by whisker deprivation (deprived) (left) results in weakening of L4 to L2/3 synapses and strengthening of horizontal connections in L2/3 originating from a non-deprived barrel (right) such that L2/3 in the deprived region of barrel cortex will respond strongly to the stimulation of a non-deprived whisker. (B) L2/3 neurons in deprived barrel cortex show correlated activity with L4 neurons in the non-deprived region of barrel cortex leading to strengthening of horizontal connections. Correlations with the deprived L4 are weak as the deprived whisker provides little sensory input. The potentiating and weakening windows of STDP rule are indicated in blue and red shading.