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Observational Fear as a Model of Affective Empathy in Mice
Published on: November 22, 2024
A single fear-inducing stimulus induces a transcription-dependent switch in synaptic AMPAR phenotype
Yu Liu1, Luigi Formisano, Iaroslav Savtchouk
1Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA.
Nature Neuroscience
|December 29, 2009
Summary
A single fear stimulus alters brain cell function by changing glutamate receptors, impacting learning and memory. This leads to long-lasting changes in neural networks.
Area of Science:
- Neuroscience
- Molecular Biology
- Synaptic Plasticity
Background:
- Emotional states influence neuronal excitability, learning, and memory.
- Experience-dependent neuronal plasticity involves gene transcription regulation.
- Fear conditioning can induce long-lasting neural changes.
Purpose of the Study:
- To investigate how fear stimuli alter synaptic plasticity in the cerebellum.
- To identify the molecular mechanisms underlying fear-induced changes in neuronal function.
- To determine the impact of altered synaptic receptors on neural network activity.
Main Methods:
- Induction of fear stimulus in mice.
- Measurement of GluR2 mRNA abundance.
- Analysis of AMPA receptor (AMPAR) composition at synapses.
- Investigation of noradrenaline and action potential effects.
- Assessment of intracellular Ca(2+) and ERK/MAPK signaling.
- Electrophysiological recordings in cerebellar stellate cells.
Main Results:
- A single fear stimulus increased GluR2 mRNA and synaptic GluR2-containing AMPARs in cerebellar stellate cells.
- Noradrenaline and action potential prolongation mediated the switch in AMPAR phenotype.
- Fear stimulus triggered Ca(2+)-dependent ERK/MAPK signaling, leading to new GluR2 gene transcription.
- This resulted in a shift from Ca(2+)-permeable to Ca(2+)-impermeable AMPARs over hours.
- Altered glutamate receptor phenotype modified synaptic efficacy.
Conclusions:
- Fear conditioning induces long-term changes in synaptic receptor phenotype.
- This molecular switch alters the function of inhibitory cerebellar networks.
- Fear-related emotional experiences can lead to lasting modifications in neural circuit activity and function.
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