Related Experiment Video
Updated: Jul 17, 2026
07:58
Free-floating Immunostaining of Mouse Brains
Published on: October 7, 2021
Structural changes at synapses after delayed perfusion fixation in different regions of the mouse brain
Jung-Hwa Tao-Cheng1, Paul E Gallant, Milton W Brightman
1EM Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
The Journal of Comparative Neurology
|February 15, 2007
Summary
A delay in brain perfusion fixation mimics ischemic stress, causing significant structural changes in postsynaptic densities (PSDs) and neuronal cells. These findings offer criteria to assess fixation quality and understand metabolic stress effects.
Area of Science:
- Neuroscience
- Cell Biology
- Microscopy
Background:
- Postsynaptic densities (PSDs) are crucial for synaptic function.
- Ischemia-like conditions induce rapid structural changes in hippocampal PSDs.
- Perfusion fixation is a standard method for preserving brain structure.
Purpose of the Study:
- To investigate structural changes in mouse brain PSDs and neuronal cells following delayed perfusion fixation.
- To establish criteria for assessing perfusion fixation quality in structural studies.
- To understand brain structural alterations under metabolic stress.
Main Methods:
- Electron microscopy was used to examine PSDs and neuronal structures.
- Mouse brains were subjected to delayed transcardial perfusion fixation.
- Quantification of PSD thickness, alpha-calcium calmodulin-dependent protein kinase II (alpha-CaMKII) labeling, and cytoplasmic CaMKII clusters.
Main Results:
- Delayed fixation significantly increased PSD thickness in the hippocampus, cerebral cortex, and cerebellar cortex.
- alpha-CaMKII labeling increased in PSDs and formed cytoplasmic clusters, with cell-specific patterns.
- Purkinje cells showed unique responses, including PSD curvature and sub-PSD sphere formation.
Conclusions:
- Delayed perfusion fixation induces cell-specific structural changes in PSDs and neuronal somas, mimicking aspects of ischemic stress.
- These changes provide markers for evaluating perfusion fixation quality.
- The findings shed light on subtle structural alterations in the brain following metabolic stress.
