Related Experiment Videos
Quantitative morphology of synaptic plasticity in the aging brain
C Bertoni-Freddari1, W Meier-Ruge, J Ulrich
1Center of Cytology, Gerontological Research Department of the INRCA, Ancona, Italy.
Scanning Microscopy
|June 1, 1988
Summary
Quantifying synaptic changes in aging brains reveals impaired plasticity. While synapse size can increase, overall synapse number and contact area decrease, particularly in dementia.
Area of Science:
- Neurobiology
- Gerontology
- Cellular Neuroscience
Background:
- Quantifying synaptic ultrastructure is crucial for detecting subtle changes in neurobiology.
- Qualitative assessments of synaptic alterations are often insufficient unless extreme.
Purpose of the Study:
- To investigate the number (numerical density), size (average length), and surface contact area (surface density) of synaptic junctions in aging rodent and human brains.
- To assess the impact of aging and dementia on synaptic plasticity and morphology.
Main Methods:
- Analysis of synaptic junction parameters: numerical density (Nv), average length (L), and surface density (Sv).
- Comparative study of synaptic morphology in aging rodent and human brains, including demented subjects.
Main Results:
- Synapse number and size exhibit an inverse relationship, maintaining constant total surface contact area.
- Aging significantly reduces synapse number and total surface contact area, impairing morphological plasticity.
- In aging brains, persistent synapses may enlarge to compensate for reduced density.
- Demented brains show further decreases in numerical and surface densities compared to normal aging, with constant synapse size.
Conclusions:
- Synaptic plasticity is significantly impaired during aging.
- Reduced synaptic contact area in aging brains may be partially compensated by increased individual synapse size.
- Dementia exacerbates the loss of synaptic numerical and surface densities, indicating severe synaptic alterations.