Pain – feared, misunderstood and even poeticized in works of art and literature – has long captivated the scientific imagination of Clifford Woolf since his days as a medical student in South Africa.

Woolf, a Harvard Medical School professor of neurobiology and neurology at Boston Children’s Hospital, has been on a quest to understand the basic mechanisms of pain and to help spark the development of more effective therapies to alleviate pain, especially ones that don’t have the abuse potential of opioids.

Woolf is the senior author of a newly published study using optogenetics – a technique that uses genetic engineering to render neurons in living tissue sensitive to laser light.

Using this approach in mice, Woolf and colleagues successfully identified the exact cascade of pain–related behavioral responses evoked by stimulating neurons that exclusively sense pain–inducing stimuli.

The findings, published July 5 in the journal Cell Reports, reveal some big surprises and cast a new light the classic dogma of pain reflex responses first described a century ago by the neurophysiologist and Nobel laureate Sir Charles Sherrington.