RT Journal Article
SR Electronic
T1 Duodenal Sensory Neurons Project to Sphincter of Oddi Ganglia in Guinea Pig
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 8065
OP 8073
DO 10.1523/JNEUROSCI.18-19-08065.1998
VO 18
IS 19
A1 Kennedy, Audra L.
A1 Mawe, Gary M.
YR 1998
UL http://www.jneurosci.org/content/18/19/8065.abstract
AB Retrograde labeling of duodenum–sphincter of Oddi (SO) preparations in vitro with the carbocyanine dye DiI revealed that duodenal neurons project to the SO. The duodenum–SO-projecting neurons were immunoreactive (IR) for choline acetyltransferase but not nitric oxide synthase or calretinin, indicating that this is a cholinergic projection and that this pathway is distinct from the circuitry involved in the ascending limb of the peristaltic reflex. Approximately 20% of the duodenum–SO projection neurons were IR for calbindin. Calbindin-IR nerves within SO ganglia degenerated when the SO was maintained in organ culture alone, but persisted when the SO was cultured with the duodenum intact. Therefore, SO ganglia are a target of the calbindin-positive duodenum–SO projection. Because calbindin is a marker of intrinsic sensory neurons that have processes that pass to the mucosa, these neurons are in position to detect the release of a compound from the mucosa and signal its release to SO ganglia. When applied to retrogradely labeled neurons, cholecystokinin (CCK) elicited a prolonged depolarization, indicating that duodenum–SO-projecting neurons could be capable of detecting CCK released from the mucosa. It is proposed that the role of the intrinsic sensory neurons that project to the SO may be to signal the postprandial release of CCK, thus providing an instruction to decrease SO resistance and facilitate the flow of bile into the duodenum.