Figure 4.

General morphological changes of TTL5 neurons during development. (A) Representative 3-D model neurons reconstructed from biocytin-labeled neurons at all ages examined (dendrites in red, axons in blue). Scale bar, 200 μm. (B1) Total length of both basal (white bars) and apical (gray bars) dendrites significantly increased from P7 to P14. Only the total length of basal dendrites further increased from P36 to P60. (B2) Total number of apical dendritic segments significantly decreased from P7 to P14. From P21 to P60, there was a significant increase in the total number of basal dendritic segments. (C1) Total axonal length significantly increased from P7 to P14. (C2) Total number of axonal segments significantly increased from P7 to P14. Note that the data for the axons of neurons at P36 and P60 are insufficient for the analyses of total length and segment number. This is because axonal collaterals in slices from P36 and P60 rats were often invisible at deep focusing levels under LM.