Induction of long-term potentiation and depression is reflected by corresponding changes in secretion of endogenous brain-derived neurotrophic factor.
Neurotrophins play an important role in modulating activity-dependent neuronal plasticity. In particular, threshold levels of brain-derived neurotrophic factor (BDNF) are required to induce long-term potentiation (LTP) in acute hippocampal slices. Conversely, the administration of exogenous BDNF prevents the induction of long-term depression (LTD) in the visual cortex. A long-standing missing link in the analysis of this modulatory role of BDNF was the determination of the time-course of endogenous BDNF secretion in the same organotypic preparation in which LTP and LTD are elicited. Here, we fulfilled this requirement in slices of perirhinal cortex. Classical theta-burst stimulation patterns evoking LTP lasting >180 min elicited a large increase in BDNF secretion that persisted 5-12 min beyond the stimulation period. Weaker theta-burst stimulation patterns leading only to the initial phase of LTP ( approximately 35 min) were accompanied by a smaller increase in BDNF secretion lasting <1 min. Sequestration of BDNF by TrkB-IgG receptor bodies prevented LTP. Low-frequency stimulations leading to LTD were accompanied by reductions in BDNF secretion that never lasted beyond the duration of the stimulation.
Aicardi
Giorgio
G
Department of Human and General Physiology, University of Bologna, Via San Donato 19/2, I-40126 Bologna, Italy.
Argilli
Emanuela
E
Cappello
Silvia
S
Santi
Spartaco
S
Riccio
Massimo
M
Thoenen
Hans
H
Canossa
Marco
M
D000818:Animals; D001921:Brain / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism* / Q000502:physiology; D004594:Electrophysiology; D018728:Entorhinal Cortex / Q000502:physiology; D006624:Hippocampus / Q000502:physiology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation; D036881:Long-Term Synaptic Depression; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D019208:Brain-Derived Neurotrophic Factor