Gaskell, Langley, and the "para-sympathetic" idea
- Institut de Biologie de l’ENS (IBENS), Inserm, CNRS, École normale supérieure,PSL Research University, France
Figures
Figure 1
Arrangement of autonomic fibers according to Gaskell.
(A) The three types of involuntary fibers recognized by Gaskell: the myelinated fibers (purple and red) project from the CNS, either to the paravertebral chain, through the ramus visceralis and …
Figure 2
Categorization of autonomic nerves according to Gaskell and Langley (A), and according to genetically-defined cell types (B).
In (A) the vagus nerve and the sacral splanchnic are put in the same category (parasympathetic, green) despite their projections in different types of roots: dorso-ateral (and dedicated) for the …
Figure 3
Different embryonic origins but similar migration pathways of preganglionic neurons at spinal and hindbrain levels.
At spinal levels (A, A’) — including sacral ones— preganglionic neurons (red) arise embryonically (A) from the same progenitor domain (pMN) as somatic motoneurons (black), with which they share an …
Figure 4
The visceral nerves of a dog as they appear in figure V, plate III, from Gaskell, 1886 (enhanced for clarity).
‘Vaso-inhibitory nerves’ are represented in red and are found at cranial and sacral levels.
Figure 5
A dog’s penis and its innervation (reproduced and adapted from François-Franck, 1895).
HN: hypogastric nerve; IMG inferior mesenteric ganglion (or plexus); PG: pelvic ganglion (or hypogastric plexus); PN; pelvic nerve or nervus erigens of Eckhardt. 1, 2, & 3: electrostimulation sites …
Figure 6
Cardiac ganglionic neurons of three morphological types recognized by Dogiel (reproduced in Testut, 1911, after Dogiel 1894).
Testut provides tens of references and comments: “Despite this body of work, the question of cardiac ganglia is far from settled, owing in part to the difficulty of the subject”. Not much has …
Figure 7
Langley’s cladogram of the peripheral nerves as it appears in The Autonomic nervous system Part I.
The “bulbo-sacral” outflow is unified across an anatomical gap that spans most of the spinal cord, but the ocular (or tectal) is in a separate subclass, despite being cranial, like the bulbar.
Figure 8
Provisional schematic of the polytomous, or mosaic autonomic outflow, based on published data (for the lumbosacral outflow, which was tentatively named ‘pelvosympathetic’; Sivori et al., 2023), unpublished data (for the oculomotor outflow), and educated guesses (for cardiac ganglia).
The lumbo-sacral outflow is distinguishable from the sympathetic (red) mostly at the level of post-ganglionic neurons, in the pelvic ganglion (pink). The genetic differences between the three …
