Samantha J. Butler, Ph.D.

The extraordinarily diverse functions of the nervous system, from cognition to movement, are possible because neurons are assembled into precisely ordered networks that permit them to rapidly and accurately communicate with their synaptic targets. For nearly two decades, Butler has been at the forefront of understanding the mechanisms that establish and regenerate this neural circuitry.

By pursuing a greater understanding of how the nervous system is established, Butler hopes to determine how this process can be recreated or co-opted to regenerate diseased or damaged nerves and nerve circuits. Her work overturned a long-standing paradigm about how axons — thread-like projections that connect cells in the nervous system — grow during embryonic development. Butler discovered that neural progenitors organize axon growth by producing a pathway of a protein called netrin1 that leads them through their local environment. 

This insight into axon growth could enable scientists to use netrin1 to enhance and accelerate recovery in patients with serious nerve damage, such as veterans with combat injuries. Without intervention, these patients face lengthy and painful recovery times, and can lose both movement and sensation in the injured limb due to the gradual loss of nerve cells after injury. 

Butler recently created a method for producing all types of sensory interneurons from mouse stem cells and is now working to replicate this work in human cells. If successful, this could be a key step toward the development of stem cell-based therapies to regenerate or repair damaged or abnormal sensory neurons, which can result from physical trauma or injury, chemotherapy, autism, aging or other diseases.