HEPES prevents edema in rat brain slices
D G MacGregor1, M Chesler, M E Rice
1Department of Physiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA.
Neuroscience Letters
|April 27, 2001
Summary
Brain slice edema, or swelling, is reduced by using HEPES-buffered artificial cerebrospinal fluid (ACSF). This indicates that tissue acidosis contributes to brain slice swelling.
Area of Science:
- Neuroscience
- Physiology
- Biochemistry
Background:
- Brain slices swell when incubated in bicarbonate-buffered artificial cerebrospinal fluid (ACSF) at 35°C.
- Previous research linked this edema to glutamate receptor activation and oxidative stress.
- Acidosis, caused by high CO2 tension, is another potential contributor to slice swelling.
Purpose of the Study:
- To investigate the role of tissue acidosis in brain slice edema.
- To determine if altering buffering capacity affects slice water gain.
Main Methods:
- Incubating brain slices in HEPES-buffered ACSF (HEPES-ACSF) to increase buffering capacity.
- Measuring water gain in brain slices under different buffering conditions.
- Assessing the concentration-dependent effect of HEPES on slice water gain.
Main Results:
- Water gain in brain slices was significantly inhibited when using HEPES-ACSF.
- After 3 hours in HEPES-ACSF, water gain was comparable to fresh slices recovering in standard ACSF.
- HEPES demonstrated a concentration-dependent inhibition of water gain, effective between 0.3 and 20 mM.
Conclusions:
- Tissue acidosis is a contributing factor to brain slice edema.
- Modulating buffering capacity with HEPES can mitigate slice swelling.
- These findings highlight the importance of pH regulation in maintaining brain slice integrity.
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