Activity-dependent release of endogenous brain-derived neurotrophic factorfrom primary sensory neurons detected by ELISA in situ

Citation
A. Balkowiec et Dm. Katz, Activity-dependent release of endogenous brain-derived neurotrophic factorfrom primary sensory neurons detected by ELISA in situ, J NEUROSC, 20(19), 2000, pp. 7417-7423
Citations number
69
Categorie Soggetti
Neurosciences & Behavoir
Journal title
JOURNAL OF NEUROSCIENCE
ISSN journal
02706474 → ACNP
Volume
20
Issue
19
Year of publication
2000
Pages
7417 - 7423
Database
ISI
SICI code
0270-6474(20001001)20:19<7417:AROEBN>2.0.ZU;2-O
Abstract
To define activity-dependent release of endogenous brain-derived neurotroph ic factor (BDNF), we developed an in vitro model using primary sensory neur ons and a modified ELISA, termed ELISA in situ. Dissociate cultures of nodo se-petrosal ganglion cells from newborn rats were grown in wells precoated with anti-BDNF antibody to capture released BDNF, which was subsequently de tected using conventional ELISA. Conventional ELISA alone was unable to det ect any increase in BDNF concentration above control values following chron ic depolarization with 40 mM KCl for 72 hr. However, ELISA in situ demonstr ated a highly significant increase in BDNF release, from 65 pg/ml in contro l to 228 pg/ml in KCl-treated cultures. The efficacy of the in situ assay a ppears to be related primarily to rapid capture of released BDNF that preve nts BDNF binding to the cultured cells. We therefore used this approach to compare BDNF release from cultures exposed for 30 min to either continuous depolarization with elevated KCl or patterned electrical field stimulation (50 biphasic rectangular pulses of 25 msec, at 20 Hz, every 5 sec). Short-t erm KCl depolarization was completely ineffective at evoking any detectable release of BDNF, whereas patterned electrical stimulation increased extrac ellular BDNF levels by 20-fold. In addition, the magnitude of BDNF release was dependent on stimulus pattern, with high-frequency bursts being most ef fective. These data indicate that the optimal stimulus profile for BDNF rel ease resembles that of other neuroactive peptides. Moreover, our findings d emonstrate that BDNF release can encode temporal features of presynaptic ne uronal activity.