Gut 2008;57:314-322
Neurogastroenterology
Brain-derived neurotrophic factor amplifies neurotransmitter responses and promotes synaptic communication in the enteric nervous system
Center for Gastroenterological Research, KULeuven, Leuven, Belgium
Dr Pieter Vanden Berghe, Center for Gastroenterological Research, KULeuven, Herestraat 49, Lab 701, B-3000 Leuven, Belgium; pieter.vandenberghe{at}med.kuleuven.be
Background: Besides its role in neuronal growth and differentiation, brain-derived neurotrophic factor (BDNF) has been implicated in the control of peristalsis where it serves to enhance gastrointestinal motility.
Aim: To unravel the cellular mechanisms governing BDNFs effect on motility.
Methods: Studies were performed in primary myenteric neuron cultures and whole-mount preparations derived from guinea pig ileum. Expression of BDNF and its tropomyosin-related kinase B (TrkB) receptor was assessed by immunohistochemistry. Intracellular Ca2+ concentration ([Ca2+]i) changes in myenteric neurons were monitored using Fluo-4, and neurotransmitter release kinetics at enteric synapses were evaluated with FM1-43 imaging.
Results: Immunohistochemistry revealed the presence of BDNF and TrkB in mucosa, submucosal plexus and myenteric ganglia. Primary cultures also expressed BDNF and TrkB and were used to study the physiological effects of BDNF. None of the neurons studied displayed a [Ca2+]i change when challenged with BDNF. However, BDNF exposure caused an enhancement of Ca2+ transients induced by serotonin and substance P, which was reversed by the Trk receptor blocker K-252a (0.1 µM). BDNF exposure also resulted in an amplification of spontaneous network activity which was reflected in an increased number of synaptic vesicle clusters. Furthermore, BDNF treatment facilitated FM1-43-labelled vesicle destaining in enteric terminals during field stimulation.
Conclusions: The findings demonstrate that BDNF is able to enhance rather than directly activate enteric nervous system signalling. Therefore, the promotion of motility by BDNF seems to result from its potent modulating role on enteric neuronal activity and synaptic communication.
Relevant Article
- Digest
- Robin Spiller and Magnus Simren
Gut 2008 57: 1-2.[Extract] [Full Text] [PDF]
Register for free content
The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.
Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.
