Korean J Aerosp Environ Med.
1999 Jun;9(2):192-197.
Effect of Brain-derived Neurotrophic Factor on Excitatory Synaptic Transmission in Hippocampal Neurons
- Affiliations
-
- 1Department of Physiology, Keimyung University School of Medicine, Taegu, Korea.
- 2Department of Neurosurgery, Keimyung University School of Medicine, Taegu, Korea.
Abstract
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Brain-derived neurotrophic factor (BDNF) rapidly enhances synaptic transmission among the
hippocampal neurons in the resting state. This mechanism may be due to the phosphorylation of
NMDA receptors through its Trkb receptors on the postsynaptic neuron. In contrast, BDNF also
has a suppressing effect on the synaptic transmission via non-NMDA receptors. The activities of
non-NMDA receptors are known to modulate the NMDA receptors activities. This study was to
investigate, using patch clamp technique, whether the BDNF increases or decreases the
glutamate-induced synaptic transmission in which glutamate acts on both NMDA- and non-NMDA
receptors. When a postsynaptic neuron was previously excited by a large amount of glutamate,
BDNF decreased the synaptic transmission induced by subsequently-applied glutamate. However,
when the signal entered into a postsynaptic neuron was blocked by the application of
tetrodotoxin, BDNF increased the glutamate-induced responses. These results show that BDNF
plays a role in a protection of the neurons against hazardous or uncontrolled activation of
glutamate receptors and in an accentuation of the synaptic response when the signal is
inevitably diminished.