Cellular Neurophysiology

DRG neurons are sensory neurons that have an important function in nociception and chronic pain. They transmit information from the periphery to the central nervous system via synaptic transmission, which can be modulated by the concomitant release of neuroactive peptides. Our aim is to understand how both types of release are regulated independently (Fig. 1).

 We showed that the priming factors CAPS1 and  2 play a major role in the differential regulation of synaptic transmission and neuropeptide release. CAPS1, is expressed in all DRG neurons where it accumulates in pre-synaptic boutons (Fig. 2 & 3) and regulates specifically synaptic transmission (Fig. 4). In contrast, CAPS2 is exclusively expressed in the peptidergic sub-population of DRG neurons where it promotes the release of neuropeptides. It has a diffuse localization in the cell soma and neurites. This distinct localization of CAPS paralogs is due to a unique N-terminal amino acid sequence in CAPS1. We are currently investigating the function of CAPS2 in DRG neurons in more detail.

Figure 3: anatomie of a synapse revealed by STED microscopy. Labelled are the active zone protein bassoon and CAPS1 in A or Munc13-1 in B