Central autonomic network
The efferent counterpart to the interoceptive afferent system — the machinery that acts on the body once its state has been represented. Bonaz et al. (2021) put it at the centre of their account of how interoceptive dysfunction becomes physical illness, and it fills a gap the wiki had been working around: this material had been distributed across visceromotor-areas (the cortical issuers of allostatic prediction), hpa-axis (the endocrine limb) and amygdala (the trigger), with nothing naming the system they belong to.
What it is
Per Bonaz et al.’s glossary, the CAN “controls the activity of preganglionic sympathetic and parasympathetic neurons in the dynamic control of visceral function.” It is hierarchically organized and integrated with interoceptive representations, and it spans:
| level | structures |
|---|---|
| cortical/forebrain | anterior cingulate cortex, insula, amygdala |
| subcortical | hypothalamus |
| brainstem | autonomic nuclei (NTS, parabrachial, PAG) |
| spinal | preganglionic centres |
Its function is to orchestrate autonomic, endocrine, motor and behavioural responses together — including stress responses and immune reactivity — “for adaptative survival within an uncertain external environment” (Beissner et al. 2013). The wiki’s existing pages hold pieces of this: the insula and ACC as limbic sensory/motor pair (Craig), the amygdala’s central nucleus driving sympathetic and HPA output (LeDoux), the agranular visceromotor cortices issuing descending predictions (EPIC). The CAN is the name for their union.
Reflexes enslaved by policies
The architectural claim is the one worth keeping, and it is a strong one:
Lower-order homeostatic reflexes couple afferent interoceptive signaling to specific efferent physiological outputs (e.g., in baroreflex control of blood pressure), yet these reflexes are enslaved by descending signals from the CAN that reflect more general, higher-order ‘allostatic policies’.
So the baroreflex is not an autonomous loop that higher centres occasionally interrupt; its set-point is continuously written from above in service of anticipated demand. This is allostasis given a concrete efferent implementation, and it is the same picture Petzschner et al. (2021) describe control-theoretically as the difference between a reflex arc with a fixed set-point and flexible control that moves it. Bonaz et al. add that both reflexes and allostatic responses “mostly operate unconsciously,” with interoceptive sensations reaching consciousness — and attracting appraisal — “especially in pathological states.”
Why it carries the clinical argument
The CAN is what makes Bonaz et al.’s “dysfunction at any level” claim mechanically coherent. If the system is one hierarchy from belief to preganglionic neuron, then a disturbance introduced anywhere propagates in both directions — a cortical belief can produce a gut symptom, and a peripheral pathology can distort representation. That is the logic behind treating IBS, chronic-pain, pelvic pain and dysautonomia as interoceptive conditions rather than as separate specialties’ problems.
Dysautonomia — any disorder of autonomic function, increasingly including conditions defined by primary maladaptive autonomic reactivity (vasovagal syncope, hyperhidrosis, postural tachycardia syndrome) rather than by nerve damage — is the CAN’s own failure mode, and the review’s link between joint-hypermobility and affective symptoms runs through it.
Relation to polyvagal theory
Worth stating because the two are easy to conflate. The CAN is the mainstream, uncontroversial description of central autonomic control, resting on lesion, stimulation and imaging meta-analysis. polyvagal-theory is a specific and contested proposal about the evolutionary organization of the parasympathetic branch. Nothing on this page depends on the three-division scheme, and Bonaz — a vagus researcher — does not invoke it.