My home page | Home

Synaptic competition for neurotrophins

The development of connections between neurons and their target cells often involves an initial stage of superinnervation followed by elimination of axons. In some cases, elimination continues until the target is innervated by just a single axon (e.g., in the neuromuscular junction), whereas in many other cases various innervating axons remain.

Competition among axons for target-derived neurotrophins (survival promoting factors) is thought to play a key role in axon elimination. Although the notion of competition is widely used, there is little understanding of the nature of the competitive process and the underlying mechanisms.

Our model prediction that competition requires neurotrophins to upregulate the number of their own receptors (Van Ooyen and Willshaw, 1999) has recently been confirmed experimentally in a study showing that nerve growth factor (NGF) promotes the expression of its own receptor TrkA, and that perturbation of this feedback disrupts the dynamics of synaptic competition (Deppmann et al., 2008).



My home page | Home