Online. Zoom link sent by email.
Central control of breathing, dissection of functional modules
Our work addresses the neural bases of breathing, a vital, comparatively simple and evolutionary conserved behavior in vertebrates. We aim at identifying the principles by which neuronal circuits orchestrate accurate and timely control of behavior.
Respiratory circuits, reside in the apparently chaotic anatomy the hindbrain, which has few obvious nuclei, no columns or layers and, in many places, an amorphous appearance subsumed under the vague term “reticular formation”. Inspired by developmental logics we try to unravel neuronal subpopulations identified by molecular signatures that are organized into specific circuits with dedicated executive functions.
I will consider the breathing clock in the mouse, report on its development, its constitutive V0 and Phox2b neurons and show the importance of their homotypic (e.g. V0 to V0) and heterotypic (e.g. Phox2b to V0) connectivity for respiratory rhythm generation, bilateral synchrony and metabolic adaptation.
These questions will be tackled using multiple approaches that include mouse genetics, viral-based circuit tracing, functional manipulation (opto-/chemo-genetics) and biophysical means (e.g. electro-physiology, calcium imaging…) for quantitative behavioral analysis.
Relevant papers:
Thoby-Brisson M, Karlén M, Wu N, Charnay P, Champagnat J, Fortin G. Genetic identification of an embryonic parafacial oscillator coupling to the preBötzinger. Nat Neurosci 12(8):1028-1035.
Bouvier J, Thoby-Brisson M, Renier N, Dubreuil V, Ericson J, Champagnat J, Pierani A, Chédotal A, Fortin G. Hindbrain interneurons and axon guidance signaling critical for breathing. Nat Neurosci 2010 13(9):1066-74
Ruffault PL, D’Autréaux F, Hayes JA, Nomaksteinsky M, Autran S, Fujiyama T,Hoshino M, Hägglund M, Kiehn O, Brunet JF, Fortin G, Goridis C. The retrotrapezoid nucleus neurons expressing Atoh1 and Phox2b are essential for the respiratory response to CO₂. eLife 2015
Wu J, Capelli P, Bouvier J, Goulding M, Arber S, Fortin G. A V0 core neuronal circuit for inspiration. Nat Commun. 2017
Organized by Bordeaux Neurocampus, NBA and Bordeaux Neurocampus Graduate Program
Gilles Fortin
CNRS
IBENS (Institut de Biologie de l’École Normale Supérieure)