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Palisade endings: cholinergic sensory organs or effector organs?
Roland Blumer1, Kadriye Zeynep Konakci, Christine Pomikal
1Center of Anatomy and Cell Biology, Medical University Vienna, Vienna, Austria. roland.blumer@meduniwien.ac.at
Investigative Ophthalmology & Visual Science
|October 22, 2008
Summary
Palisade endings in monkey extraocular muscles are cholinergic motor organs, not sensory. This clarifies their function and rules them out as providing eye-position signals.
Area of Science:
- Neuroscience
- Muscle Physiology
- Ocular Motor System
Background:
- Prior research on monkey extraocular muscle (EOM) palisade endings is complemented.
- The sensory or motor role of palisade endings remains unclear.
Purpose of the Study:
- To determine if palisade endings are cholinergic motor or sensory.
- To investigate the innervation of palisade endings in EOMs.
Main Methods:
- Analysis of macaque EOMs (n=10) using 3D reconstruction and microscopy.
- Triple fluorescent labeling with cholinergic markers (ChAT, ChT, VAChT) and alpha-bungarotoxin.
- Immunotransmission electron microscopy for ChAT localization.
Main Results:
- Palisade endings originate from ChAT-positive axons.
- Neuromuscular and neurotendinous contacts within palisade endings are cholinergic.
- Motor terminal features and alpha-bungarotoxin binding confirm motor function.
Conclusions:
- Palisade endings are confirmed as cholinergic motor organs.
- They are unlikely to be involved in providing eye-position signals.
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