Pathophysiological aspects of acute experimental allergic encephalomyelitis

Area of Science:

• Neuroscience
• Pathophysiology
• Immunology

Background:

• Experimental allergic encephalomyelitis (EAE) research traditionally focuses on immunology and histopathology.
• EAE involves small, focal lesions in the central nervous system (CNS), necessitating high-resolution physiological studies.

Purpose of the Study:

• Introduce a physiological approach to studying EAE.
• Investigate regional pathophysiology in EAE using high-resolution methods.
• Correlate regional histopathology with pathophysiology in EAE.

Main Methods:

• Utilized quantitative autoradiography for high spatial resolution (approx. 50 µm) and precise quantitation.
• Assessed regional blood-brain barrier (BBB) permeability in EAE.
• Examined regional energy substrate metabolism, including cerebral blood flow (CBF) and cerebral metabolic rate for glucose (CMRglc).

Main Results:

• Significant increase in BBB permeability observed at EAE lesion sites (lymphocytic accumulations).
• Energy metabolism severely deranged in lesions, indicated by an elevated CBF/CMRglc ratio (3 ml/µmol vs. normal 1.5 ml/µmol).
• No regional pH changes detected in lesions; a 50% decrease in cerebral cortex blood flow noted, possibly due to sensory-motor impairment.

Conclusions:

• Quantitative autoradiography is an effective method for studying EAE pathophysiology.
• EAE lesions are associated with increased BBB permeability and disrupted energy metabolism.
• Physiological changes in EAE extend beyond lesion sites, affecting overall cerebral blood flow.