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Updated: Apr 20, 2026
09:30
Assessment of Long-term Depression Induction in Adult Cerebellar Slices
Published on: October 16, 2019
7.5K
Enhanced AMPA receptor function promotes cerebellar long-term depression rather than potentiation
Boeke J van Beugen1, Xin Qiao2, Dana H Simmons3
1Department of Neuroscience, Erasmus University Medical Center, 3000 DR Rotterdam, The Netherlands Department of Neurobiology, University of Chicago, Chicago, Illinois 60637, USA.
Learning & Memory (Cold Spring Harbor, N.Y.)
|November 19, 2014
Summary
Ampakines, such as CX546, enhance synaptic transmission in the cerebellum but promote long-term depression (LTD) instead of long-term potentiation (LTP). This suggests ampakines can selectively regulate synaptic plasticity in different brain regions.
Area of Science:
- Neuroscience
- Synaptic Plasticity
- Pharmacology
Background:
- Ampakines are AMPA receptor modulators known to enhance hippocampal long-term potentiation (LTP) and learning.
- They are investigated for treating cognitive and memory deficits.
Purpose of the Study:
- To investigate the effects of the ampakine CX546 on cerebellar synapses.
- To determine if CX546 influences synaptic transmission and calcium signaling in cerebellar Purkinje cells.
- To examine the impact of CX546 on long-term potentiation (LTP) and long-term depression (LTD) at these synapses.
Main Methods:
- Electrophysiological recordings of excitatory postsynaptic currents (EPSCs) at cerebellar parallel fiber (PF) to Purkinje cell synapses.
- Monitoring of dendritic calcium transients using the fluorescent indicator Oregon Green BAPTA-2 and ultra-high-speed CCD imaging.
- Application of the ampakine CX546 during recordings.
Main Results:
- CX546 increased the amplitude and slowed the decay time of EPSCs at cerebellar PF-Purkinje cell synapses.
- CX546 enhanced and prolonged PF-evoked calcium transients in Purkinje cell dendrites.
- Contrary to hippocampal effects, CX546 facilitated long-term depression (LTD) rather than LTP at cerebellar PF synapses.
Conclusions:
- Ampakines selectively modulate the balance between LTP and LTD depending on the brain region and synapse type.
- CX546 enhances cerebellar synaptic transmission and dendritic calcium signaling.
- These findings suggest ampakines could be tools for targeted regulation of synaptic memories.
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