Effect of alcohol on the postnatal development of corpus callosum of albino rat

Abstract EN

Pregnant female albino rats were allowed free access to 10% ethanol as the only source of liquid starting from day 17 of pregnancy.

Their pups were exposed to the same treatment after weaning.

These pups, together with age matched controls, were sacrificed at 0, 5,10,20,30 and 60 days of age.

Sections of the brain were stained with gallocyanin and Holms silver technique.

Ultrathin sections were prepared from 30 and 60 days old pups for electron microscopy.

In alcohol treated animals the corpus callosum showed a decrease in its thickness especially in the older age groups.

The neuralgia cells appeared to be more densely packed in the newly born rats, while in the older age groups they appeared irregularly arranged with areas of degeneration.

The callosal fibers appeared pale with ill defined outline in the silver stained sections.

Electron microscopic examination revealed that, while in the 60 days old control animals most of the callosal fibers were myelinated, the alcohol treated animals showed many unmyelinated fibers.

The diameter of the myelinated fibers AS well as the number of myelin lamella were significantly reduced in the alcohol treated animals at this age.

The alcohol treated animals showed reduction in the sectional area of the corpus callosum which was significant at 30 & 60 days of age.

The genu showed earlier effects than other parts.

Similar reduction in the sectional area of the cerebral hemisphere appeared in the alcohol treated animals resulting in absence of changes in the volume proportion of the corpus callosum in the cerebral hemisphere in most age groups.

This could indicate that the reduction in the callosal area was a part of the changes taking place in the brain due to alcohol.

Longer period of alcohol exposure (age of 60 days), seems to have affected the corpus callosum more severely than the rest of the brain.

This appeared in the form of significant reduction in the volume proportion of the corpus callosum at this particular age