Background. Colonic contractile patterns are the result of the interplay of spontaneous
pacemaker currents and the enteric nervous system (ENS). Aim. To describe the motility
patterns displayed by human colonic strips in vitro and to summarize the adequate
parameters to study enteric neurotransmission. Methods. We collected mechanical data
from 15 patients (54 circularly-oriented strips, sigmoid colon). Results. All strips
displayed rhythmic phasic contractions (RPCs) at 2.9 ± 0.3 c.p.m. RPCs appeared together with high-amplitude contractions at 0.13 ± 0.02 c.p.m in 30% of the preparations. Another 30% displayed a pattern in which RPCs waxed
and waned their amplitude with a frequency of 0.28 ± 0.03 c.p.m. probably leading to segmentation. Modulation of slow wave amplitude by the
second pacemaker could be the underlying mechanism of this pattern. Storage of colonic
contents is accomplished by a nitric oxide (NO)-mediated sustained inhibition of contractile
activity. Non-adrenergic, non-cholinergic conditions are needed to study inhibitory
neurotransmission. L-NNA or MRS2500 should be used to further isolate purinergic or
nitrergic responses respectively. Purinergic responses are dominant at low frequencies
of EFS (>1 Hz) or short bursts while high frequencies are needed to release NO (>1 Hz). Excitatory neurotransmission should be characterized under non-nitrergic, non-purinergic
conditions. The duration of the neuronal burst might determine if the response is
mainly cholinergic (1 s) or if it also involves the release of tachykinins (10 s). Conclusion. RPCs, high-amplitude contractions and wax and wane are the main motility
patterns displayed by human colonic strips. The ENS can be involved the origin, development
and/or modulation of motility patterns and generation of contractions and relaxations.
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Autonomic Neuroscience: Basic and ClinicalAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
Article info
Identification
Copyright
© 2015 Published by Elsevier Inc.