ISSN:
1432-0878
Keywords:
Enteric nervous system
;
Glia
;
Astrocytes
;
HRP, interacellular labeling
;
Fractal geometry
;
Guinea pig
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Glial cells of the myenteric plexus from guinea pig small intestine were intracellulary filled with horseradish peroxidase (HRP), and histochemically stained. Camera lucida-like drawings of twenty cells were morphologically and morphometrically analyzed. The cells have very small ellipsoid, somata (85±0.7 μm equivalent diameter, i.e., about 330 μm3 volume), and send up to 20 thin and short processes (less than 26 to about 110 μm in length). The morphology of the cells appears to depend on their location within the plexus. Glial cells located within the ganglia are similar to CNS protoplasmic astrocytes; they are star-shaped, and their very short processes are irregularly, branched. In contrast, glial cells within the interganglionic fiber tracts resemble CNS fibrous astrocytes. They extend longer processes that are parallel to the fiber tracts, and show less tendency to branch. We propose that the morphology of enteric glia is determined by the structure of the microenvironment. Both cell types form several flat endfeet at a basal lamina either surrounding blood vessels or at the ganglionic border. Furthermore, the occurrence of “holes” in the glial cell processes suggests that particular neuronal cell processes may be enwrapped in a specific manner. Fractal analysis of camera lucida-like drawings of the cells showed that the cells have a highly complex surface structure, comparable to that of protoplasmic astrocytes in the brain. These tiny cells may possess a membrane surface area of ∼2000 μm2, almost 90% of which are contributed by the cell processes. This geometry may enable an intense exchange of metabolites and ions between neurons, glial cells, and the capillaries and/or environment of enteric ganglia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00305787
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