Related Experiment Video
Updated: Mar 31, 2026

Targeting Alpha Synuclein Aggregates in Cutaneous Peripheral Nerve Fibers by Free-floating Immunofluorescence Assay
Published on: June 25, 2019
Enteric nervous system α-synuclein immunoreactivity in idiopathic REM sleep behavior disorder
Fabienne S Sprenger1, Nadia Stefanova1, Ellen Gelpi1
1From the Departments of Neurology (F.S.S., N.S., K.S., B.H., B.F., G.K.W., W.P.) and Gastroenterology (W.V.), Medical University of Innsbruck, Austria; Neurological Tissue Bank of the Biobanc-Hospital Clinic de Barcelona (E.G.), IDIBAPS; the Departments of Neurology (J.N.-O., D.V., F.V., C.P.-S., C.G., A.I., E.T.), Pathology (I.A., M.C.), and Gastroenterology (A.G.), Hospital Clinic de Barcelona, Spain; and the Institute of Pathology (F.O.), Academic Teaching Hospital, Feldkirch, Austria.
Objective:
To investigate the expression of α-synuclein in colonic biopsies of patients with idiopathic REM sleep behavior disorder (iRBD) and address if α-synuclein immunostaining of tissue obtained via colonic biopsies holds promise as a diagnostic biomarker for prodromal Parkinson disease (PD).
Methods:
Patients with iRBD, patients with PD, and healthy controls were prospectively recruited to undergo colonic biopsies for comparison of α-synuclein immunoreactivity patterns between the groups by using 2 different antibodies.
Results:
There was no difference in colonic mucosal and submucosal immunostaining between groups using the 15G7 α-synuclein antibody, which was found in almost all participants enrolled in this study. By contrast, immunostaining for serine 129-phosphorylated α-synuclein (pSyn) in submucosal nerve fibers or ganglia was found in none of 14 controls but was observed in 4 of 17 participants with iRBD and 1 out of 19 patients with PD.
Conclusions:
The present findings of pSyn immunostaining of colonic biopsies in a substantial proportion of iRBD participants raise the possibility that this tissue marker may be a suitable candidate to study further as a prodromal PD marker in at-risk cohorts.
Related Concept Videos
REM Sleep Behavior Disorder
RBD is significantly associated with...
Neural Regulation
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
Narcolepsy

