Quantification revealed a significant increase in the average normalized fluorescence intensity for all bins posterior to the position of maximal fluorescence intensity in the nucleus in MiTMAB-treated cells (Figure 5I), and the rearward redistribution of adhesion proteins occurred whether or not the neuron displayed a trailing process.
However, neurons migrating in vivo may require a distinct mechanism to regulate adhesion at the rear if they leave a trailing process or grow an axon during migration.
For example, in migrating SVZa neurons and tangentially migrating interneurons, which do not extend an obvious trailing process during migration, myosin II at the rear of the cell aids in somal translocation [5], [11].
Bipolar cells were mainly radially-oriented, showing the typical morphology of migrating elements, with a leading and a trailing process (Figure 1E).
In normal SVZa neurons, few migrating cells retain a trailing process (Figure 5A).
However, neurons exposed to MiTMAB for at least 2 hours were more likely to exhibit a trailing process or tail (Figure 5B).
AnkG immunostaining was never detected in bipolar migrating MNs, neither in their leading nor in their trailing process (n = 6; 49 neurons) (Fig. 3a, b).
After 1 DIC, electroporated MNs could be found at different stages of differentiation, as revealed by GFP, which labeled either the leading and trailing processes of early post-mitotic MNs migrating toward the peripheral MN pool (Fig. 3a, b), or the axon and dendrites of more mature MNs (Fig. 3c e).
However, we saw no overt alterations in the organization of actin or microtubules in MiTMAB-treated neurons (data not shown), apart from the failure of migrating neurons to resolve their trailing processes at the cell rear.
In this case, the question is how to allocate the treatments to the incoming patients so that the criteria/mechanisms of interest are assessed during the trail process, and the overall performance of the trial is optimized under the combined criteria or regimes.
