Neuroplasticity is implicated in causing both NDO and AD, mediated by reformation of spinal reflex arcs and bladder afferent neurons
The neural circuit mediating this escape behavior is reasonably well understood, and consists of known afferent neurons
, command interneurons, central pattern generator interneurons, and efferent flexion neurons (Fig.
In 80% of trigeminal afferent neurons
originating from meninges, ASIC-like currents can be evoked at pH 6.0, and over 50% are also responsive to pH 7.0 .
TRPA1 and SP are expressed in intrinsic and extrinsic primary afferent neurons
; these are critical in the visceral pain and stress response (31,32).
Furthermore, local sensory neurons called intrinsic primary afferent neurons
(IPANs) regulate motility and maintain homeostasis.
Yeon et al., "Eugenol inhibits sodium currents in dental afferent neurons
," Journal of Dental Research, vol.
In neurogenic inflammation, local afferent neurons
secrete inflammatory mediators such as neurokinin A, substance P (SP), and calcitonin gene-related peptide which perpetuate inflammation.
From these studies [24-26], it can be shown that the convergence of AP signals and visceral noxious afferent neurons
in the spinal cord and the upper center is the neurobiological basis of AP for relieving visceral pain.
Synaptic connections with efferent and afferent neurons
are both observed in this the DG .
Regarding their function, submucosal neurons are divided into motor neurons, interneurons, intrinsic primary afferent neurons
(IPANs) and intrinsic fleeting afferent neurons
During the storage phase, these afferent neurons
fire at low frequencies because the bladder wall is insufficiently stretched.
Regardless of the mechanism, damaged primary afferent neurons
undergo similar changes.
Similarly in tissue trauma or surgery, release of other mediators of pain like 5HT, along with substance P may sensitize primary afferent neurons
causing pain in cases of nerve entrapment pain or scar pain.
(1992) Central connections of trigeminal primary afferent neurons
: topographical and functional considerations.
Despite having damaged afferent neurons
, the efferent pathway is still intact allowing pupil constriction in both eyes.