Histological and Biochemical Alterations in the Superior Colliculus and Lateral Geniculate Nucleus of Juvenile Rats Following Prenatal Exposure to Marijuana Smoke

Abstract

Prenatal exposure to marijuana has been associated with a variety of brain deficits, as Δ9-tetrahydrocannabinol (THC), its main active ingredient crosses the placenta and affects foetal brain development. Despite this effect, marijuana remains a commonly abused substance among pregnant women. In the current study, we examined the histological and biochemical changes in the superior colliculus (SC) and lateral geniculate nucleus (LGN) in rat brains prenatally exposed to marijuana. Four groups of pregnant rats (n = 5) were exposed to the smoke of 10 g/kg BW marijuana at various days during the 21-23 days duration of rat gestation, with a group (Control) which is not exposed. After parturition, the litters from each group were sacrificed by cervical dislocation on postnatal days 7, 14, and 21; and the superior colliculi and lateral geniculate nuclei were excised. Tissue sections were prepared for histological studies using Haematoxylin and Eosin stains. Biochemical studies were done on the activity levels of alkaline phosphatase, acid phosphatase, lactate dehydrogenase, and glucose-6-phosphate dehydrogenase. Histological and biochemical analyses of tissues were performed. Prenatal exposure to marijuana resulted in spontaneous abortion as well as affected neuronal morphology in the SC and LGN of the progeny. Also, levels of enzyme activities were altered following maternal exposure to marijuana. These data suggests that histological changes in the SC and LGN is associated with oxidative damage.