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Postnatal NMR changes in guinea pig central nervous system: Potential relevance to experimental allergic encephalomyelitis
Author(s) -
Noseworthy J. H.,
Gilbert J. J.,
Vandervoort M. K.,
Karlik S. J.
Publication year - 1988
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910060208
Subject(s) - encephalomyelitis , white matter , central nervous system , pathology , relaxometry , guinea pig , medicine , magnetic resonance imaging , multiple sclerosis , spinal cord , immunology , spin echo , psychiatry , radiology
The age of sensitization determines the clinical course of experimental allergic encephalomyelitis (EAE) in the guinea pig. Adult animals immunized with central nervous system (CNS) tissue develop acute, fulminant EAE, whereas a relapsing‐remitting illness resembling multiple sclerosis occurs if sensitization occurs in the first 2 weeks of life. This study characterized the changes in the proton nuclear magnetic resonance (NMR) relaxometry and imaging of the CNS during the immediate postnatal period. T 1 and T 2 relaxation times in cerebral hemispheres and spinal cords of strain 13 guinea pigs were consistently prolonged at birth, progressively shortened in the first few weeks of life, and achieved adult levels by age 6 to 11 weeks. There were no age‐dependent differences in T 1 and T 2 relaxation times and tissue specific gravity in either strain 13 or Hartley guinea pigs following immunization with complete Freund's adjuvant, an agent previously reported to disrupt the blood‐brain barrier to IgG and albumin in strain 13 guinea pigs. The CNS of neonatal guinea pigs appeared well myelinated by light microscopy and there was no apparent difference in the extent of myelination between newborn and adult animals. Although it was possible to distinguish gray from white matter in the cervical spinal cord of newborn guinea pigs by magnetic resonance imaging (MRI) techniques, gray/white contrast was less satisfactory in the cerebral hemispheres until approximately 6 weeks of life when it was possible to differentiate gray matter, white matter, and cerebrospinal fluid. This study indicates that NMR relaxation times change during early postnatal life, at a time corresponding to the unexplained differences in susceptibility to an immune challenge. These developmental changes appear to be independent of the degree of CNS myelination. © 1988 Academic Press, Inc.