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Reduced presynaptic efficiency of excitatory synaptic transmission impairs LTP in the visual cortex of BDNF-heterozygous mice.
- Source :
-
The European journal of neuroscience [Eur J Neurosci] 2006 Dec; Vol. 24 (12), pp. 3519-31. - Publication Year :
- 2006
-
Abstract
- The neurotrophin brain-derived neurotrophic factor (BDNF) plays an important role in neuronal survival, axonal and dendritic growth and synapse formation. BDNF has also been reported to mediate visual cortex plasticity. Here we studied the cellular mechanisms of BDNF-mediated changes in synaptic plasticity, excitatory synaptic transmission and long-term potentiation (LTP) in the visual cortex of heterozygous BDNF-knockout mice (BDNF(+/-)). Patch-clamp recordings in slices showed an approximately 50% reduction in the frequency of miniature excitatory postsynaptic currents (mEPSCs) compared to wild-type animals, in the absence of changes in mEPSC amplitudes. A presynaptic impairment of excitatory synapses from BDNF(+/-) mice was further indicated by decreased paired-pulse ratio and faster synaptic fatigue upon prolonged repetitive stimulation at 40 Hz. In accordance, presynaptic theta-burst stimulation (TBS) failed to induce LTP at layer IV to layers II-III synapses during extracellular field-potential recordings in BDNF(+/-) animals. Changes in postsynaptic function could not be detected, as no changes were observed in either the amplitudes of evoked EPSCs, the ratios of AMPA : NMDA currents or the kinetics of evoked AMPA and NMDA EPSCs. In line with this observation, an LTP pairing paradigm that relies on direct postsynaptic depolarization under patch-clamp conditions could be induced successfully in BDNF(+/-) animals. These data suggest that a chronic reduction in the expression of BDNF to nearly 50% attenuates the efficiency of presynaptic glutamate release in response to repetitive stimulation, thereby impairing presynaptically evoked LTP in the visual cortex.
- Subjects :
- Animals
Animals, Newborn
Brain-Derived Neurotrophic Factor deficiency
Calcium pharmacology
Dose-Response Relationship, Drug
Dose-Response Relationship, Radiation
Electric Stimulation methods
Excitatory Amino Acid Agonists pharmacology
Excitatory Amino Acid Antagonists pharmacology
In Vitro Techniques
Long-Term Potentiation drug effects
Long-Term Potentiation radiation effects
Mice
Mice, Knockout
N-Methylaspartate pharmacology
Neurons drug effects
Neurons radiation effects
Patch-Clamp Techniques methods
Presynaptic Terminals drug effects
Presynaptic Terminals radiation effects
Quinoxalines pharmacology
Synaptic Transmission drug effects
Synaptic Transmission radiation effects
Time Factors
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid pharmacology
Brain-Derived Neurotrophic Factor metabolism
Long-Term Potentiation physiology
Neurons physiology
Presynaptic Terminals physiology
Synaptic Transmission physiology
Visual Cortex cytology
Subjects
Details
- Language :
- English
- ISSN :
- 0953-816X
- Volume :
- 24
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- The European journal of neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- 17229100
- Full Text :
- https://doi.org/10.1111/j.1460-9568.2006.05242.x