Effect of Cannabis Inhalation on the Hippocampus of Male Wistar Rats

Cannabis is the second most commonly smoked substance after tobacco, with an estimated 160 million users (3.8% of the world’s population of 15-64 year olds). There are other smokeless forms of cannabis consumption like being added to food. This study is focused on the effect of cannabis inhalation on the hippocampus of Wistar rats. Twenty (20) male Wistar rats weighing 70-100g were separated into 4 groups of 5 rats each; Group A served as positive control and received water and rat chow. Group B rats were placed in the ventilation box without exposure to the cannabis smoke for 10 minutes daily throughout the duration of this study. Group C were exposed to 1g of Cannabis smoke for 10-minutes daily for 14 days while Group D were exposed to 2g of Cannabis smoke for 15-minutes. 24 hours after the last exposure, rats were weighed and subjected to Morris water maze neurobehavioural test for memory. The rats were then sacrificed by cervical dislocation and the brain was harvested. Some were homogenized and centrifuged for biochemical assay while the others were fixed in 10% formal saline for histological tissue processing using the H & E. The findings of this study reveal that cannabis smoke does not affect Wistar rats' body weight and brain weight on short-term exposure. However, it shows mild focal inflammations and alterations in the normal neuronal architecture of the hippocampal cells. On the other hand, the study revealed a decreased learning pattern and memory retrieval time following short-term cannabis smoke exposure in neurobehavioural parameters.