Marked morphological differences in the myenteric plexus between the mesenteric and antimesenteric sides of small
1Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin, Ireland.
Insights
Premature infants show higher myenteric plexus neuron density on the small bowel
Area of Science:
- Gastroenterology
- Neonatal Physiology
- Neuroscience
Background:
- Gastrointestinal tract develops by the second trimester, but enteral nutrition physiology matures later (33-34 weeks).
- The myenteric plexus regulates peristalsis, crucial for gut motility.
- Whole-mount preparation visualizes complex neuronal networks.
Purpose of the Study:
- To investigate the neuron density and morphology of the myenteric plexus in premature infants.
- To utilize whole-mount preparation for detailed analysis of the myenteric plexus.
Main Methods:
- Autopsy specimens from 6 premature infants (26-32 weeks gestation) and 4 full-term controls.
- Whole-mount preparation of the myenteric plexus.
- Staining with NADPH-diaphorase and Acetylcholinesterase (AChE); analysis via computer imaging.
Main Results:
- Significant differences in myenteric plexus neuron density between mesenteric and antimesenteric borders in premature infants.
- These density differences diminished with advancing gestation, absent by 32 weeks.
- Controls showed no such border differences.
Conclusions:
- Premature infants exhibit significantly higher myenteric plexus neuron density on the mesenteric border compared to the antimesenteric border of the small bowel.
- Observed morphological differences in neuron density may explain immature small bowel activity in premature infants.
Background:
The gastrointestinal tract appears morphologically prepared for oral feeding by the end of the second trimester, but many of the physiological processes required for efficient enteral nutrition are not developed fully until 33 to 34 weeks' gestation. Myenteric plexus is well recognized as an important regulator of peristaltic activity. Whole-mount preparation technique produces a 3-dimensional picture to better show the neuronal networks branching and interconnections. The aim of this study was to investigate neurone density and morphology of the myenteric plexus in premature infants using whole-mount technique.
Methods:
Full-thickness small and large bowel specimens were collected at autopsy from 6 premature babies (gestational age, 26 to 32 weeks) who died without evidence of gastrointestinal disease. Whole-mount preparation of the myenteric plexus was made and stained with NADPH-diaphorase and Acetylcholinesterase (AChE) histochemistry. The stained myenteric network was measured with a computer image analysis system. Controls included 4 full-term babies who died of nongastrointestinal disease.
Results:
In premature infants there were striking differences in neuronal density of myenteric plexus in the mesenteric and antimesenteric border of small bowel. The differences in neuronal density in mesenteric and antimesenteric border of small bowel gradually became less striking as the gestation progressed with no differences evident at gestational age 32 weeks.
Conclusions:
This study shows for the first time that the neurone density of myenteric plexus is significantly higher in the mesenteric border of the small bowel compared with antimesenteric border in premature infants. The marked morphological differences observed in neurone density in the small bowel of premature infants may contribute to immature small bowel activity.
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