5 Questions with an Expert on the Sense of Touch

Why study the sensory neurons of touch?

Touch is a fundamental sense, yet there’s so much we don’t know about it. We know relatively little about the primary sensory neurons. We know even less about how their projections are organized to give rise to circuits that underlie the perception of touch. And we know very little about how this organization develops. Touch is fascinating and complicated.

Okay, so I’m holding a pen. What do and don’t we know about how I accomplish that?

We know your muscles are controlling your gripping of the pen. We don’t know the circuits that are mediating the sense of the pen, the force being applied, or the slippage of that pen within your grasp. Presumably there are spinal circuits where those sensory inputs are turned into motor outputs that adjust grip control, but we don’t know about the components of those circuits. We don’t know how or where information from the different sensory neurons that detect pressure versus stretch versus vibration are integrated to give rise to the perception of your experience of holding that pen.

Describe one avenue you’re pursuing.

Given that we have a dozen or more types of sensory neurons, each of which is tuned to different types of stimuli—for instance, some respond best when the skin is indented, others to the stretching of the skin, and others to temperature changes—our thesis is that sensory neurons’ activities are integrated in the spinal cord, which then sends integrated information to the brain’s somatosensory cortex, where we perceive the nature of the stimulus acting on the skin.

We’re asking how second-order neurons, post-synaptic partners of sensory neurons, and spinal cord interneurons process touch information in the spinal cord, and how that processed information is then sent to the brain.

What motivates you?

We do discovery-based, curiosity-driven research. We’re fascinated with how sensory systems develop and function. We’re convinced that the knowledge we gain will provide the basis for understanding what happens when things go wrong—and, perhaps, how to fix things.

What do you love about being a scientist?

If, when I was young, I had to say what I would choose as a career, I would have said artist or musician. So I’m lucky; I think being a scientist is a lot like being an artist. Science and art share an open-mindedness and a desire to explore the unknown. In science, as in art, creativity, inquisitiveness, and presentation play huge roles.

I love discovering something beautiful and telling the world about it. In science, when something is discovered and it’s right, it’s beautiful. And there’s no greater joy than describing that beautiful something to the world. It’s hard to imagine a more satisfying career.

Image: John Soares