Dopamine Transporter Genetic Reduction Induces Morpho-Functional Changes in the Enteric Nervous System

Area of Science:

• Neurogastroenterology
• Dopaminergic Neurotransmission
• Gut-Brain Axis

Background:

• Antidopaminergic prokinetics are used for motility disorders, but gut dopamine's role is unclear.
• Dopamine transporter (DAT) affects brain function; its gut role is unexplored.
• The enteric nervous system (ENS) controls gut motility.

Purpose of the Study:

• To investigate the impact of reduced dopamine transporter (DAT) activity on the mouse small intestine's enteric nervous system (ENS).
• To assess functional and structural changes in the ENS and gut motility due to DAT genetic reduction.

Main Methods:

• Compared DAT heterozygous (DAT+/-) and wild-type (DAT+/+) mice.
• Assessed small intestinal contractility using isometric assessment of neuromuscular responses.
• Analyzed ENS integrity via real-time PCR and confocal immunofluorescence microscopy.

Main Results:

• DAT genetic reduction increased dopamine D1 receptor-mediated effects.
• Observed reduced cholinergic response linked to tachykininergic and NMDA receptor neurotransmission.
• Found architectural changes in myenteric plexus neurochemical coding and S100β immunoreactivity.
• Associated functional anomalies with ileal dysmotility.

Conclusions:

• Genetic DAT deficiency causes ENS architectural and neurochemical anomalies.
• Defective DAT activity leads to ileal dysmotility.
• Suggests the dopaminergic system is involved in gut disorders, potentially linked to neurological conditions.