CEREBRAL ALTERATIONS INDUCED BY ASPHYXIA DURING BIRTH ARE PREVENTED WITH HYPOTHERMIA AFTER INSULT.

LOIDL, C. F. ; CEBRAL, E. ; SELVÚ-TESTA, A.; CAPANI, F.; LÓPEZ-COSTA, J. J.; LOPEZ, E. M.; PAZ, F. ; SAAVEDRA, J. P

San Diego

Congreso; Society for Neuroscience Meeting; 2001

SFN

Perinatal asphyxia (PA) is a transient global ischemia that may induce behavioral deficits and neuropathological damage. We used as a model rats obtained from full term pregnant rats. Their uteri-containing fetuses were extracted and subjected to transient immersion in 37??C water during 20 min (severe PA). After one month we studied striatum and cerebral cortex in asphyctic animals. We used immunocitochemistry (both light and electron microscopy) with antibodies to nNOS (neuronal nitric oxide synthase), 250 kD NF (neurofilaments) and GFAP (gliofibrillar acidic protein). The remarkable finding was cytomegalia in nNOS neurons evidenced by increase in their soma size and an enlargement of their processes with evident tortuous dendritic arborizations. Increase of 250 kD NF and GFAP in the same cerebral areas indicates neurodegeneration as well as astroglial hypertrophy. A group of newborn rats that suffered severe PA were placed on ice during 5 min after resuscitation. In these one old month animals the immunoreaction in all studied areas resembled those observed in controls. These data suggest that severe PA induces neuronal and astroglial changes, possibly along a cascade of events in which an excess of nitric oxide in the environment may contribute to brain damage. A short exposure to ice immediately after insult could contribute to long-lasting neuroprotection improving cerebral alterations. These results may have clinical outcome in patients that suffered severe asphyxia during birth.