Dopamine is produced in the rat spinal cord and regulates micturition reflex after spinal cord injury.

Dopamine is produced in the rat spinal cord and regulates micturition reflex after spinal cord injury.
Exp Neurol. 2016 Nov;285(Pt B):136-146
Authors: Hou S, Carson DM, Wu D, Klaw MC, Houlé JD, Tom VJ
Abstract
Dopamine (DA) neurons in the mammalian central nervous system are thought to be restricted to the brain. DA-mediated regulation of urinary activity is considered to occur through an interaction between midbrain DA neurons and the pontine micturition center. Here we show that DA is produced in the rat spinal cord and modulates the bladder reflex. We observed numerous tyrosine hydroxylase (TH)(+) neurons in the autonomic nuclei and superficial dorsal horn in L6-S3 spinal segments. These neurons are dopamine-β-hydroxylase (DBH)(-) and some contain detectable dopamine decarboxylase (DDC), suggesting their capacity to produce DA. Interestingly, following a complete thoracic spinal cord injury (SCI) to interrupt supraspinal projections, more TH(+) neurons emerged in the lumbosacral spinal cord, coincident with a sustained, low level of DA expression there and a partially recovered micturition reflex. Non-selective blockade of spinal DA receptors reduced bladder activity whereas activation of spinal D2-like receptors increased bladder activity and facilitated voiding. Additionally, depletion of lumbosacral TH(+) neurons with 6-hydroxydopamine (6-OHDA) decreased bladder non-voiding contractions and voiding efficiency. Furthermore, in...

Source: Experimental Neurology - October 26, 2016 Category: Neurology Authors: Hou S, Carson DM, Wu D, Klaw MC, Houlé JD, Tom VJ Tags: Exp Neurol Source Type: research