Human disorders of axon guidance

By understanding this we can apply this to axons that need to find their way to reconnect after a stroke.
http://www.sciencedirect.com/science/article/pii/S0959438812000281

Axon pathfinding is essential for the establishment of proper neuronal connections during development. Advances in neuroimaging and genomic technologies, coupled with animal modeling, are leading to the identification of an increasing number of human disorders that result from aberrant axonal wiring. In this review, we summarize the recent clinical, genetic and molecular advances with regard to three human disorders of axon guidance: Horizontal gaze palsy with progressive scoliosis, Congenital mirror movements, and Congenital fibrosis of the extraocular muscles, Type III.

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Highlights

► We review recent advances in understanding three human disorders of axon guidance. ► ROBO3 mutations cause HGPPS and hindbrain/spinal cord midline crossing defects. ► DCC mutations cause congenital mirror movements and probably midline crossing defects. ► TUBB3 mutations cause syndromic strabismus and callosal and cranial nerve defects.

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Figures and tables from this article:

Figure 1. Schematic of axon guidance defects in HGPPS, CMM, and CFEOM3. With normal guidance (purple): corticospinal tract (CST) axons navigate from the motor cortex to the spinal cord, decussating in the medulla (cell bodies labeled ‘1’); corpus callosum (CC) and anterior commissure axons cross from one hemisphere to the other (cell bodies labeled ‘2’); interneuron populations decussate in the hindbrain (cell bodies labeled ‘3’); and oculomotor axons extend to their target extraocular muscles (EOM, cell bodies labeled ‘4’). In HGPPS (blue), CST and hindbrain interneuron axons fail to decussate, resulting in ipsilateral projections. In CMM (green), it is proposed but not proven that while some CST axons decussate appropriately, others fail to do so and project ipsilaterally. In CFEOM3 (brown), there is variable thinning of the CC and anterior commissure axons, supporting abnormal guidance of these axonal tracts. The oculomotor nerve (CNIII) also has abnormal guidance, resulting in the dysinnervation of EOM. AR = autosomal recessive; AD = autosomal dominant.