Research Highlight: A V0 core neuronal circuit for inspiration
Breathing involves permanent rhythmic contractions of skeletal muscles in a bilaterally synchronized manner. The executive control of respiration relies on sets of brainstem interneurons assembled into an ordered synaptic network: the respiratory central pattern generator (CPG). The ENP group leader Gilles Fortin and coll. investigate the relationship of defined neuronal subtypes to the organization of the respiratory CPG.
They had previously demonstrated that the inspiratory rhythm generator —the preBötzinger complex (preBötC)— is composed of V0 glutamatergic neurons that arise from neural progenitors expressing the homeobox gene Dbx1. They now have used monosynaptic viral tracing from the inspiratory diaphragm muscle to locate, identify the origin and the excitatory or inhibitory nature of inspiratory premotor neurons. Their work reveals the existence of a core inspiratory motor circuit in which V0 cell lineages form both the rhythm generator and its main premotor follower. This V0 core circuit features built-in redundant commissural connectivity to bilaterally secure the temporal synchronicity and the balanced amplitude of rhythmic inspiratory motor drives that are required for efficient breathing.
Check out the article:
A V0 core neuronal circuit for inspiration. Wu J, Capelli P, Bouvier J, Goulding M, Arber S, Fortin G. Nat Commun. 2017 Sep 15;8(1):544. Doi: 10.1038/s41467-017-00589-2.
Figure: A, retrograde tracing schemes. B, inspiratory premotor map. C, V0 axon terminals on inspiratory motoneurons. D, Left(L)-right(R) de-synchronization of inspiratory drives following invalidation of Robo3 in V0 neurons.