Introduction: Formaldehyde (FA) exposure is a widely growing worldwide problem. It is not only confined to outdoor occupational exposure but extends indoors owing to the domestic use of multiple FA containing materials. Many FA induced neurological adverse effects have been reported. The cerebellum, being a part of the nervous system responsible for coordination, fine movements and motor learning, thus its affection may cause hazardous effects.
Aim of work: to study the effect of FA exposure on the cerebellar cortical tissue and the possible reversibility of these effects upon withdrawal.
Materials and methods: thirty adult male albino rats, aging 4-6 months and weighing 200 - 250 gms, were used in this study. Animals were divided equally into three groups; Group I: control group. Group II: subjected to 10 % FA inhalation for 8 hours/day, 6 days/week for four weeks. Group III: subjected to FA inhalation for the same duration as group II then left for another four weeks without exposure. At the end of the experiment for each group, specimens were collected and processed for light and electron microscopic examination and morphometric studies.
Results: Examination of sections of group II revealed significant decrease in thickness of both molecular and granular layers. Purkinje layer showed multiple focal areas of loss, dark irregular cells with highly significant decrease in diameter and marked ultrastructural abnormalities. However, group III showed insignificant increase in thickness of molecular and granular layers. Purkinje layer exhibited irregular alignment of cells, areas of focal loss and others with multi-layering. Purkinje neurons varied widely in shape, size and ultrastructural findings with insignificant increase in their mean diameter. Increased neuroglial cells was also noted in groups II and III.
Conclusion: Formaldehyde inhalation might cause irreversible insult to the cerebellar cortex, thus avoidance or limitation of exposure is highly recommended.