Changes in normal and apoptotic pyramidal neuronal cell densities in prefrontal cortex of the male rat following chronic khat use

Abstract

Long-term Khat consumption is associated with significant neuro-cognitive changes, which have been elucidated in behavioral studies. However, correlation of these neurophysiological changes with experimental structural changes in prefrontal neurons has not been described adequately. Young adult male Winstar rats, aged 2-3 months, weighing 200-300 grams were randomized into four groups of 11 each to correspond with those used as controls, those that received 500mg/kg, 1000mg/kg and 2000mg/kg body weight khat extracts respectively. The control rats were fed on normal diet, while experimental groups were fed on normal diet and khat extracts using oral gavage for 6 weeks. The animals were sacrificed, and their brains removed. Toluidine blue staining was used to elucidate the Nissl substance. Image-Fiji was used to analyse densities of normal and apoptotic pyramidal neuronal densities across the 4 experimental groups. Normal pyramidal neurons were identifiable by their characteristic uniform size and prominent nucleoli, while apoptotic cells displayed prominent eosinophilia and pyknotic nuclei. There was a statistically significant increase in apoptotic pyramidal neurons across the three khat-fed groups compared to controls, and a decrease in normal pyramidal neuronal population from controls with increasing doses of khat. This decrease in normal pyramidal neurons and increase in apoptosis could be a potential surrogate for neurocognitive perturbations associated with chronic khat use.