Periventricular leukomalaci (PVL) is critically dependent upon the presence of extracellular ions (Ca2+ and Na+)

Abstract

This work is clarifying the role of extracellular ions in PVL in neonates. Ischaemic injury of adult brain
was critically dependent upon the presence of extracellular Ca²+ as revealed by a range of studies (Stys
et al., 1992). Along with they found that two extracellular ions were essential for the development of
permanent loss of function during ischaemia in adult brain: Ca²⁺ and Na⁺. The dependence of ischaemic
injury in adult upon both Ca²⁺ and Na⁺ indicates that these ions are potentially toxic to cell viability by
causing permanent loss to axonal function. Therefore, the effects of these two ions during 90 min
oxygen-glucose deprivation (OGD), (the practical model of ischaemia) in neonatal brain were
investigated using electrophysiology techniques for compound action potential (CAP) recording. This
produced the interesting finding that removal of either Ca²⁺ or Na⁺ from the extracellular space
protected the neonatal brain from ischaemic injury during OGD. When Ca²⁺ or Na⁺ were removed from
the extracellular space during 90 min OGD, the CAP declined at the end of OGD. Afterward, the CAP
recovered following restoration of normal conditions. The results of this study indicated that,
extracellular Ca²⁺ and Na⁺ are essential for the development of permanent loss of function during OGD
in neonatal brain.