Blocking brain-derived neurotrophic factor inhibits injury-induced hyperexcitability of hippocampal CA3 neurons

Gill, Raminder; Chang, Philip K.-Y.; Prenosil, George; Deane, Emily C.; McKinney, Rebecca A. (2013). Blocking brain-derived neurotrophic factor inhibits injury-induced hyperexcitability of hippocampal CA3 neurons. European journal of neuroscience, 38(11), pp. 3554-3566. Blackwell Science 10.1111/ejn.12367

Full text not available from this repository.

Brain trauma can disrupt synaptic connections, and this in turn can prompt axons to sprout and form new connections. If these new axonal connections are aberrant, hyperexcitability can result. It has been shown that ablating tropomyosin-related kinase B (TrkB), a receptor for brain-derived neurotrophic factor (BDNF), can reduce axonal sprouting after hippocampal injury. However, it is unknown whether inhibiting BDNF-mediated axonal sprouting will reduce hyperexcitability. Given this, our purpose here was to determine whether pharmacologically blocking BDNF inhibits hyperexcitability after injury-induced axonal sprouting in the hippocampus. To induce injury, we made Schaffer collateral lesions in organotypic hippocampal slice cultures. As reported by others, we observed a 50% reduction in axonal sprouting in cultures treated with a BDNF blocker (TrkB-Fc) 14 days after injury. Furthermore, lesioned cultures treated with TrkB-Fc were less hyperexcitable than lesioned untreated cultures. Using electrophysiology, we observed a two-fold decrease in the number of CA3 neurons that showed bursting responses after lesion with TrkB-Fc treatment, whereas we found no change in intrinsic neuronal firing properties. Finally, evoked field excitatory postsynaptic potential recordings indicated an increase in network activity within area CA3 after lesion, which was prevented with chronic TrkB-Fc treatment. Taken together, our results demonstrate that blocking BDNF attenuates injury-induced hyperexcitability of hippocampal CA3 neurons. Axonal sprouting has been found in patients with post-traumatic epilepsy. Therefore, our data suggest that blocking the BDNF-TrkB signaling cascade shortly after injury may be a potential therapeutic target for the treatment of post-traumatic epilepsy.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Department of Radiology, Neuroradiology and Nuclear Medicine (DRNN) > Clinic of Nuclear Medicine
UniBE Contributor:	Prenosil, George
Subjects:	600 Technology > 610 Medicine & health
ISSN:	0953-816X
Publisher:	Blackwell Science
Language:	English
Submitter:	Franziska Nicoletti
Date Deposited:	30 Jun 2014 15:16
Last Modified:	05 Dec 2022 14:32
Publisher DOI:	10.1111/ejn.12367
PubMed ID:	24118418
Uncontrolled Keywords:	axonal sprouting, brain-derived neurotrophic factor, GAP43, organotypic hippocampal slices, post-traumatic epilepsy
URI:	https://boris.unibe.ch/id/eprint/48321