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Updated: Apr 25, 2026
Quantification of Neurovascular Protection Following Repetitive Hypoxic Preconditioning and Transient Middle Cerebral Artery Occlusion in Mice
Published on: May 4, 2015
Effects of hypoxic preconditioning on synaptic ultrastructure in mice
Yi Liu1, Zhishan Sun, Shufeng Sun
1China-America Joint Institute of Neuroscience, CAJIN, Xuanwu Hospital, Capital Medical University, Beijing, China; Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Neuroprotection Research Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Hypoxic preconditioning (HPC) enhances tolerance to oxygen deprivation. This study reveals HPC alters synaptic structure, specifically affecting synaptic curvature and presynaptic mitochondria in the olfactory bulb.
Area of Science:
- Neuroscience
- Cellular Biology
- Physiology
Background:
- Hypoxic preconditioning (HPC) offers potential neuroprotection against severe insults.
- The precise mechanisms underlying HPC's neuroprotective effects, particularly at the synaptic level, require further investigation.
Purpose of the Study:
- To investigate the impact of repeated hypoxic preconditioning (HPC) on synaptic ultrastructure in the mouse olfactory bulb.
- To determine if HPC influences synaptic morphology and mitochondrial distribution.
Main Methods:
- Mice were subjected to multiple cycles of HPC.
- Hypoxic tolerance was evaluated using a gasp reflex assay.
- Western blotting assessed protein levels of glial, neuronal, and synaptic markers.
- Transmission electron microscopy examined synaptic ultrastructure and mitochondrial density.
Main Results:
- HPC significantly increased hypoxic tolerance.
- No significant changes were observed in glial, neuronal, or synaptic marker protein levels.
- HPC treatment led to significant alterations in synaptic curvature.
- A notable increase in the percentage of synapses with presynaptic mitochondria was observed.
Conclusions:
- Hypoxic preconditioning induces significant changes in synaptic ultrastructure within the olfactory bulb.
- These synaptic modifications, including altered curvature and increased presynaptic mitochondria, may contribute to the observed neuroprotection.
