Intrahippocampal glutamate improves spatial memory in offspring of prenatally alcohol-exposed rats

Background Prenatal exposure to alcohol has been associated with persistent neurodevelopmental disorders and behavioural impairments. Its teratogenic effects compromise neuronal growth, disrupt developmental trajectories, neurochemical balance and impair the functional integrity of neural circuits. Notably, alcohol's neurotoxicity has been shown to interfere with the release of glutamate-a principal excitatory neurotransmitter critical for synaptic transmission and neural communication. Emerging evidence suggests that post-training neurochemical modulation of the hippocampus can influence memory systems, with alterations in neurotransmitter signalling leading to changes in memory processing and performance. In this study, we aim to evaluate the impact of post-training intrahippocampal glutamate infusion on spatial memory in the offspring of alcohol-exposed female rats. We also assessed the effect of post-training glutamate infusion on hippocampal neuronal survival rate. Methods Wistar rats were employed in this study and divided into three experimental groups: control, treated, and untreated. Following four consecutive days of training in the Morris Water Maze (MWM), L-glutamate was infused directly into the hippocampus using stereotaxic surgery. After a 48-h recovery period, the animals were re-exposed to the MWM to assess spatial memory performance. Key parameters evaluated included the latency to locate the platform quadrant and the time spent within the target quadrant. At the end of the Morris Water Maze (MWM) test, the animals were sacrificed, and a histological analysis was performed using cresyl violet staining to quantify hippocampal neurons. Results Offspring in the glutamate-infused group demonstrated enhanced spatial memory performance, evidenced by a significantly reduced latency to reach the platform quadrant and increased duration spent within the target quadrant, compared to those in the untreated group. Histological analysis revealed greater hippocampal neuronal survival in the glutamate-infused group compared to the untreated group. Conclusion The present study provides evidence that targeted modulation of hippocampal glutamate levels via intrahippocampal glutamate infusion can ameliorate these deficits, enhance spatial learning, memory performance and improve the neuronal count in the hippocampus.