The role of Tetrahydrocannabinol in inducing disrupted signaling cascades, hippocampal atrophy and memory defects.

Tetrahydrocannabinol (THC), a major psychoactive constituent of marijuana, can substantially change the function of several brain areas, leading to behavioral impairment including memory and learning dysfunction. Given the importance of hippocampus as one of the chief parts of the brain involved in memory processing, the present study seeks to investigate structural and histological alterations in hippocampus as well as behavioral defects provoked by THC treatment. Besides, using genome-wide sequencing, we adopted a pathway-based approach to discover dysregulated molecular pathways. Our results demonstrated remarkable hippocampal atrophy, and also interrupted memory function and long term potentiation (LTP) under THC exposure. We also detected several dysregulated signaling pathways involved in synaptic plasticity as well as cell-cell interaction in the hippocampus of THC-treated rats. Overall, the results indicate a potential correlation between disrupted signaling cascades, hippocampal atrophy and memory defects caused by THC treatment.

Methamphetamine administration impairs behavior, memory and underlying signaling pathways in the hippocampus.

Methamphetamine (METH) is a strong psychostimulant drug which can essentially affect different brain regions. Hippocampus as one of main components of limbic system plays key roles in processing of short term, long term and spatial memory. Herein, we explored the changes in behavior, synaptic transmission and hippocampal volume along with gliosis following METH treatment. Besides, using genome-wide expression profiling, we applied a pathway-based approach to detect significantly dysregulated signaling pathways. In this regard, we found that METH administration interrupts spatial memory and long term potentiation (LTP). Additionally, stereological analysis revealed a significant alteration in hippocampal volume along with increased gliosis upon METH treatment. We also identified several signaling cascades chiefly related to synaptic transmission which were considerably interrupted in the hippocampus of METH-treated rats. Taken together, our data suggests a potential link between behavioral disruptions and dysregulated signaling pathways.