The Effect of ascorbic acid injection into the lateral ventricle on spatial learning and memory in adult male rats

Introduction: Ascorbic acid (AA) acts as an antioxidant in the central nervous system (CNS) of the mammalians. It is released from some nerve endings together with neurotransmitters and previous studies have shown that ascorbic acid could affect learning as well as memory. In this study, the effect of intracerebro ventricular (ICV) injection of ascorbic acid on spatial learning and memory was examined by Morris water maze. Methods: 42 adult male NMRI rats weighing 250- 300 g were used in this study. Cannulas were implanted bilaterally in the lateral ventricles (LV) (AP=-0.8, LA= +/- 1.5, DV= 3.4). After the recovery period, the animals were divided into 6 groups. The control group received no injection. Four groups were assigned as experimental groups and received different doses of ascorbic acid (25, 50, 100 and 150 mg/kg) and the 6th group was assigned as the shamoperated group that received normal saline as vehicle. Injections were given in 5 consecutive days. Thirty min after each injection the rats were trained in the Morris Water Maze (MWM) and spatial learning and memory parameters were recorded and then analyzed. Results: ICV injection of ascorbic acid reduced spatial learning and memory in rats. This reduction reached statistical significance with the dose of 100 mg/kg of ascorbic acid. Conclusion: It can be concluded that ascorbic acid decreases spatial learning and memory, which can be due to direct or indirect interference with the effects of neurotransmitters.