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Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology
Published on: March 23, 2011
Mechanism for increased hippocampal synaptic strength following differential experience
1Department of Pharmacology, University of Kentucky College of Medicine, Lexington, Kentucky 40536-6209, USA. Tfoster@pop.uky.edu
Journal of Neurophysiology
|April 5, 2001
Summary
Environmental enrichment enhances hippocampal synaptic strength. This involves increased quantal size and potentially new synaptic connections, suggesting plasticity beyond presynaptic release.
Area of Science:
- Neuroscience
- Synaptic Plasticity
- Behavioral Neuroscience
Background:
- Environmental novelty and training enhance hippocampal synaptic strength.
- Understanding the mechanisms behind these synaptic changes is crucial.
Purpose of the Study:
- To investigate the mechanisms of synaptic transmission changes after differential behavioral experiences.
- To differentiate between presynaptic and postsynaptic contributions to enhanced synaptic strength.
Main Methods:
- Quantal analysis techniques applied to hippocampal CA1 synapses in rats.
- Extracellular and intracellular recordings of synaptic responses (EPSPs) and unitary events.
- Biophysical parameter estimation of synaptic transmission.
Main Results:
- Environmental enrichment increased population EPSP I/O curves and mean unitary synaptic response amplitude.
- Quantal size increased with enrichment, suggesting postsynaptic modifications.
- No significant changes in paired-pulse ratio, response failures, or quantal content were observed.
Conclusions:
- While baseline strength relies on presynaptic release, enrichment-induced potentiation involves postsynaptic changes (receptor efficacy/number).
- Emergence of new functional synaptic contacts between CA3 and CA1 cells may also contribute.
- Synaptic plasticity in the hippocampus is multifaceted, influenced by experience.
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