Regenerative Axon Growth in Normal Mice

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Regenerative Axon Growth in Normal Mice

http://www.medicalnewstoday.com/articles/113624.php

Oswald Steward, Binhai Zheng, Marc Tessier-Lavigne, Maura Hofstadter,

Kelli Sharp, and Matsudaira Yee

The corticospinal tract of mice exhibits some regenerative growth

without any therapeutic manipulation, according to Steward et al.

After complete transection of the dorsal column, a few axons appeared

to grow past the lesion via the ventral column. Axons extended from

the gray matter rostral to the injury into the white matter of the

ventral column, grew past the lesion, then reentered the gray matter

and arborized caudal to the lesion. These were unlikely to be spared

ventral corticospinal axons because the authors never saw such axons

in unlesioned mice.

Furthermore, unlike what would be expected for spared axons, the

axons found in the ventral column after lesion were contralateral to

the injected cortex, followed a circuitous route, had numerous

varicosities, and were not observed rostral or caudal to the level of

the lesion. This previously undescribed growth should be considered

in future studies of regeneration.