The effects of prenatal alcohol exposure on the morphological characteristics of spinal motoneurons

Abstract

Clinical studies and research in animals have established that alcohol consumption during pregnancy produces irreversible developmental anomalies. Deficits in fine motor performance are often noted in infants diagnosed with fetal alcohol syndrome. However, the effects of alcohol on the spinal motoneurons have not been examined. In this study, the morphometric alterations in spinal motoneurons were assessed as a result of prenatal alcohol exposure. Pregnant Sprague Dawley rats were administered with 1.0 ml of 20% ethyl alcohol per 100 gm body weight via intraperitoneal injections, and unexposed rats served as controls. Rats were perfused through the left cardiac ventricle and a complete laminectomy was performed. Spinal cord sections from the L4-5 segments were cut serially and stained for cresyl fast violet. Sections were also subjected to TUNEL assay for detection of apoptosis. Observations were made between 1 and 4 weeks after birth. Morphologic characteristics of motoneurons in the alcohol-exposed group of rats were altered. Counts and measurements revealed significant reduction in number and size of alcohol-exposed spinal motoneurons at all time points studied. Prenatal exposure to alcohol showed cytotoxic effects whereby it adversely affected both motoneuron growth and differentiation in utero.