The cellular and molecular connectome of somatic sensation

The underlying circuitry for somatic sensation remains a mystery. Although different kinds of somatic sensory neurons are specialized to respond to certain qualities of stimuli, they all release glutamate. Therefore, the way of conveying the quality of the perception onto the central nervous system must rely on precise terminations in the spinal cord dedicated to transmit specific sensations.  This hypothesis invokes a “labeled line” with peripheral and central neurons dedicated to particular sensations and a specificity encoded by connections between the dedicated neurons. The aim is to determine the connectivity underlying the physical basis of sensation by coming up with strategies enabling for the first time in a systematic way to determine in an activity-based way the cellular and molecular basis of sensation. Hence, the new technology should be based on neuronal activity and allow identification of the exact patterns of connections between all interconnected neurons with a full molecular signature of each identified neuron. Results from such strategy should reveal the connectivity underlying sensation, explain paradoxical observations of sensation and provide a better understanding of mechanisms of pain. The technology should also provide a new platform for resolving activity-based circuits underlying any type of physiological or pathophysiological process in the nervous system.