Related Experiment Videos
Synaptic structural abnormalities in the Ts65Dn mouse model of Down Syndrome
Pavel V Belichenko1, Eliezer Masliah, Alexander M Kleschevnikov
1Department of Neurology and Neurological Sciences and the Center for Research and Treatment of Down Syndrome, Stanford University Medical Center, 1201 Welch Road, Stanford, California 94305-5489, USA. pavel_belichenko@yahoo.com
The Journal of Comparative Neurology
|October 30, 2004
Summary
The Ts65Dn mouse, a model for Down syndrome, exhibits enlarged synapses and altered neuronal connections across brain regions. These widespread synaptic abnormalities in the Ts65Dn mouse model Down syndrome features.
Area of Science:
- Neuroscience
- Genetics
- Cell Biology
Background:
- The Ts65Dn mouse is a genetic model used to study Down syndrome.
- While cognitive deficits and impaired long-term potentiation are known, hippocampal structure in this model is understudied.
Purpose of the Study:
- To characterize synaptic structure in the Ts65Dn mouse model compared to control mice.
- To investigate synaptic abnormalities in the hippocampus and other brain regions.
Main Methods:
- Confocal microscopy was used to examine presynaptic boutons and dendritic structure.
- Immunohistochemistry and Lucifer yellow microinjection were employed.
- Electron microscopy confirmed synaptic structural changes.
Main Results:
- Ts65Dn mice showed significantly enlarged presynaptic and postsynaptic elements in all examined brain regions (hippocampus, cortex, entorhinal cortex, medial septum).
- Spine volume was greatly increased, affecting the entire population.
- Electron microscopy revealed enlarged boutons and spines with abnormal internal membranes.
- Decreased spine density and reorganization of inhibitory inputs were observed in the fascia dentata.
Conclusions:
- The Ts65Dn mouse exhibits widespread synaptic structural abnormalities mirroring features of Down syndrome.
- These findings establish the Ts65Dn mouse as a valuable model for studying Down syndrome-associated synapse structure and function.
- Further research is needed to understand the mechanisms driving synapse enlargement in this model.