Volume 7 Issue 8, August 2006

During development, precisely coordinated processes allow the formation of complex neural circuitry, but after CNS injury in adult mammals, functional circuits fail to reform. Recent work indicates that the recapitulation of developmental processes will be advantageous for successful functional recovery.

Glial inhibition — involving myelin inhibitors and astroglial scarring — represents one of the major barriers to regeneration after CNS injury. Knowledge of the molecular mechanisms of these processes could be crucial for developing therapies to promote axon regeneration and plasticity.

There is no known cure for spinal cord injury, although numerous promising cellular, molecular and rehabilitative strategies are being tested in animal models and clinical trials. Emerging findings suggest that a combination of therapies will lead to optimal functional outcome.

Although potential therapeutic strategies for spinal cord injury are emerging, the mechanisms underlying functional recovery are unclear. Recent work emphasizes the contribution of axon regeneration and plasticity, yet their involvement, and that of less well-explored processes, remains to be established.

The human left and right hemispheres have distinct functions. Sun and Walsh discuss recent genetic, imaging and neurological studies in an attempt to unravel the molecular mechanisms of brain asymmetry and handedness and to understand their evolutionary underpinning.

Mammals keep track of relative position and orientation by integrating self-motion cues. McNaughton and colleagues discuss the neurobiological evidence for a synaptic matrix capable of performing this task, and propose a model for how this neuronal network might arise developmentally.

Since the surprising finding that injured axons in the mature central nervous system can re-grow, there has been dramatic progress in our understanding of the molecular, cellular and circuitry level responses to injuries to the adult mammalian central nervous system. This special Focus issue highlights recent developments in this field, with a view to understanding the underlying mechanisms that will enable the development of appropriate therapeutic strategies.