Project description:Proprioceptive neurons (PNs) are essential for the proper execution of all our movements by providing muscle sensory feedback to the central motor network. Here, using deep single cell RNAseq of adult PNs coupled with advanced virus- and genetic tracings, we have molecularly identified the 3 main types of PNs (Ia, Ib and II) and unexpectedly found that they segregate into 8 subgroups. Our data further reveal a highly sophisticated organization of PNs into discrete sensory input channels with distinct spatial distribution, innervation patterns and molecular profiles, that together contribute to the sensory monitoring of complex motor behavior. Moreover, while Ib- and II-PN subtypes are specified around birth, Ia-PN subtypes diversify later along with increased motor activity and show versatility in the adult following exercise training, suggesting adaptive proprioceptive function.
Project description:Our objective was to evaluate the gene expression changes occuring in early sensory neuron development that were lost in the absence of Tmem184b and restored upon its reintroduction into mutant neurons in culture.
Project description:Integration of nutritional, microbial and inflammatory events along the gut-brain axis can alter bowel physiology and organism behaviour. The principal neural unit in the bowel encoding these stimuli is the visceral sensory neuron with endings at the mucosa, intramurally and along mesenteric blood vessels. Sensory neurons activate reflex pathways and give rise to conscious sensation, however, the diversity and division of function within these neurons is poorly understood. The identification of signalling pathways contributing to visceral sensation is constrained by the current paucity of molecular markers. Here we overcome these limitations by comprehensive transcriptomic profiling and unsupervised clustering of single colonic sensory neurons revealing 7 classes characterised from both lumbar splanchnic (LSN) and pelvic nerves (PN). We identify and classify neurons based on novel marker genes, confirm translation of patterning to protein expression and show subtype-selective differential agonist activation, describing sensory diversity encompassing all modalities of colonic neuronal sensitivity.