Role of glycyrrhiza glabra root extract in dendritic arborization and dendritic intersections of hippocampal CA1 neurons in 3-months old rats.

ABSTRACT

The hippocampus is located bilaterally in the medial temporal lobe; within the hippocampus the flow of information is unidirectional. Repeated psychological stress, aging and dementia may leads to the dendritic atrophy in CA1 pyramidal neurons of hippocampus. Accordingly, the present study was designed to investigate the role of aqueous root extract of Glycyrrhiza glabra (Gg) treatment on the dendritic arborization and dendritic intersections of hippocampal CA1 neurons in 3 months old male Wistar albino rats. The aqueous root extract of Glycyrrhiza glabra was administered orally in four different doses (75, 150, 225 and 300 mg/kg) for 2, 4 and 6 weeks duration, respectively. At the end of the spatial memory tests, the rats were sacrificed by deeply anesthetized Pentobarbitone, their brains were removed rapidly and Hippocampal CA1 region studied through Rapid Golgi staining. Hippocampal CA1 neurons were traced using camera lucida, and Quantification of dendritic branching points and dendritic intersections were quantified by using concentric circle method of Sholl. All the doses of aqueous root extract of Gg for 6 weeks showed significantly enhanced dendritic arborization and dendritic intersections however in the dose of 150 and 225 mg/kg/p.o showed a significant (p<0.01) enhancement of dendritic arborization and dendritic intersections along the length of both apical and basal dendrites in hippocampal CA1 pyramidal neurons is comparable to control. However, the rats treated for 2 and 4 weeks did not show any significant change in hippocampal CA1 neuronal dendritic arborization. Thus the constituents present in aqueous root extract of Gg may stimulate the release of neuromodulators or neuronal dendritic growth stimulating factors that alter the activity of neurotransmitters that are involved in learning and memory, which thereby may be useful in management of impaired learning, dementia, Alzheimer’s disease and other neurodegenerative disorders.