Activity-Dependent Callosal Axon Projections in Neonatal Mouse Cerebral Cortex
Figure 2
Effects of postsynaptic and presynaptic activity reduction on callosal axon projections. (a) The morphology of single callosal axons in the normal condition at P15. ((b) and (c)) postsynaptic (b) and presynaptic (c) activity reduction impede growth and branching of callosal axons. Scale bar, 200 μm. (d) An illustration showing the development of callosal axons in the mouse. Callosal axons reach the target innervation area around P5, arrive in the target cortical layers at P7, start to branch at P9, and elaborate their arbors afterwards. The effect of presynaptic activity reduction is apparent before axons reach the target cortical layers, but that of postsynaptic activity reduction is observed after their arrival in the target layers. Adapted from [41].
