FULL-LENGTH ORIGINAL RESEARCH
Impaired hippocampal memory function and synaptic plasticity in experimental cortical dysplasia
Article first published online: 14 MAR 2012
Wiley Periodicals, Inc. © 2012 International League Against Epilepsy
Volume 53, Issue 5, pages 850–859, May 2012
How to Cite
Zhou, F.-W. and Roper, S. N. (2012), Impaired hippocampal memory function and synaptic plasticity in experimental cortical dysplasia. Epilepsia, 53: 850–859. doi: 10.1111/j.1528-1167.2012.03431.x
- Issue published online: 25 APR 2012
- Article first published online: 14 MAR 2012
- Accepted January 20, 2012; Early View publication March 14, 2012.
- Cortical dysplasia;
- Synaptic plasticity
Purpose: Memory impairment is a common comorbidity in people with epilepsy-associated malformations of cortical development. We studied spatial memory performance and hippocampal synaptic plasticity in an animal model of cortical dysplasia.
Methods: Embryonic day 17 rats were exposed to 2.25 Gy external radiation. One-month-old rats were tested for spatial recognition memory. After behavioral testing, short-term and long-term synaptic plasticity in the hippocampal CA1 region was studied in an in vitro slice preparation.
Key Findings: Behavioral assessments showed impaired hippocampal CA1-dependent spatial recognition memory in irradiated rats. Neurophysiologic assessments showed that baseline synaptic transmission was significantly enhanced, whereas paired-pulse facilitation, long-term potentiation, and long-term depression of the field excitatory postsynaptic potential (fEPSP) slope at Schaffer collateral/commissural fiber-CA1 synapses were significantly reduced in the irradiated rats. Histologic observations showed dysplastic cortex and dispersed hippocampal pyramidal neurons.
Significance: This study has shown that prenatally irradiated rats with cortical dysplasia exhibit a severe impairment of spatial recognition memory accompanied by disrupted short-term and long-term synaptic plasticity and may help to guide development of potential therapeutic interventions for this important problem.