There are conflicting reports on the effect of Cannabis on brain cells, some reports support damage to brain cells while others do not. This work was carried out at the neuroscience unit of the Department of Veterinary Anatomy, University of Ibadan Oyo State, Nigeria. It investigated the neurodegenerative effect of extract of Cannabis sativa plant on brain regions in newborn Wistar rats exposed to Cannabis in utero and also combining the antioxidant and cell proliferative properties of folic acid to reverse these changes particularly in the Purkinje layer of the cerebellum in the group that received folic acid and cannabis. Four groups of pregnant Wistar rats were treated from Day 5 to 20 of pregnancy as follows: group A received 2ml of normal saline solution per os, group B received 2.0 mg /kg body weight of ethanolic extract of Cannabis sativa plant dissolved in normal saline per os, group C received 2.0 mg /kg body weight of Cannabis sativa extract and 40 mg/kg body weight of folic acid tablets (Emzor®) and group D received 2 mg/kg body weight of folic acid per os. The rat pups from group B showed deficit in locomotor function with spongiosis and astrogliosis in the corpus callosum, cerebellum and hippocampal regions of the brain. While pups from group A showed normal locomotor activities with no visible lesions in regions of the brain such as the cerebrum,cerebellum and the hippocampus. Group C pups were presented with normal locomotor activities with congestion of vessels in cerebrum and meninges and scattered areas of cell loss in the cerebrum, cerebellum hippocampus and corpus callosum and group D pups showed normal locomotor function, with vascular congestion in the meninges and cerebrum. We, therefore, concluded that folic acid which is a crucial factor in cell division, neurotransmitter production and an antioxidant in the nervous system could have a reversal of behavioural and locomotor deficits on nervous tissues exposed to Cannabis sativa extract by reducing the rate of cell death and increasing cellular stability and integrity in brain.

Keywords: Extract of Cannabis sativa, Locomotor deficit, Folic acid, Transplacental route