A general structure for the autonomic nervous system, divided into sympathetic and parasympathetic arms, was codified by John Newport Langley at the beginning of the XXth century. We propose a revision of this scheme based on neuron types. The “sacral parasympathetic” outflow is revealed to bear no resemblance to the cranial one, and to be instead a caudal elaboration of the thoraco-lumbar sympathetic system. The midbrain pathway to the eye, considered parasympathetic, is shown to belong in a class by itself. Thus the current parasympathetic division of the autonomic nervous system turns out to be a mosaic of largely unrelated cell types, in line with its multifarious physiological functions, poorly subsumed under the popular “rest and digest” motto.
Conference Room R229 – Campus Saint-Germain-des-Prés – 45 rue des Saints-Pères, 75006 Paris – Paris Cité University – November 3rd, 2023 at 11:30 AM