Memory Enhancing Effect after Medial Septum Stimulation is Associated with Changes in Hippocampal Cholinergic and Gabaergic Activity
Journal Title: The 1st Annual Meeting of Georgian Center for Neuroscience Research - Year 2020, Vol 2, Issue 20
Abstract
Many brain disorders cause impairments in learning and memory. These include developmental disorders, as well as diseases of old age such as Alzheimer’s disease. People with these disorders often show changes in the hippocampus. One way to restore the hippocampal activity is through a technique called deep brain stimulation (DBS). But exactly how DBS restores hippocampal circuit function is unclear. The medial septum (MS) is an important modulator of hippocampal function. It has been reported that DBS of MS restores spatial memory after damage to cholinergic neurons and this effect is associated with an increase in hippocampal cholinergic activity. Our study designed to quantify the effects of implantation of electrodes or MS DBS-induced changes in hippocampal dependent spatial memory function and changes in neurotransmitters markers in the hippocampus. We utilized three groups of adult male rats: normal (control), MS electrode implantation without stimulation (sham) and MS electrode implantation and stimulation. In the chronic DBS experiment, animals received stimulation 2 hr daily for a period of 2 weeks. Learning process and long-term spatial memory were assessed using a Morris water maze; the test was divided into the training phase (days 1 - 4) and the retrieval phase. The results showed that implantation of electrodes did not prevent learning of a platform location. During the probe test which was performed 1 hour after task acquisition trained rats of all groups did not differ significantly among each other, but in marked contrast from rats of control and stimulation groups, rats of electrode implantation exhibited a retention deficit 3 days later after training. These findings demonstrate that MS electrode implantation causes impairment of hippocampal dependent long-term spatial memory and MS DBS prevent this deficit. Using immunohistochemical approaches, we found that implantation of electrodes reduced the number of parvalbum inimmunoreactive MS neurons by 30% and the number of cholinacetyltranspherase immunoreactive neurons by 23% vs. control group. Our results showed that implantation of electrodes into the MS causes in hippocampal CA1 and CA3 fields significant decrease in number of AChE-sensitive neurons, but number of immunostained GABAA receptors was significantly higher in sham group as compared to control group; in MS stimulation group number of AChE-sensitive neurons and GABAA receptors in the hippocampus was not different from the control group. Taking into account the results of our behavioral and immunohistochemical experiments it can be assumed that the cholinergic and GABAergic deficiency after implantation of electrodes is compensated by stimulation of survivor MS neurons. Our results revealed that DBS of MS facilitated long-term spatial memory and for the first time demonstrate that this effect is associated with a modulation not only of hippocampal cholinergic activity, but is paralleled with significant changes in GABAergic activity. (Supported by the funding from the SRNSFG: Grant # - FR-18-11783.)
Authors and Affiliations
M. Burjanadze, G. Beselia, T. Naneishvili, M. Dashniani
Keywords
Related Articles
- EP ID EP677934
- DOI 10.29088/GCNR-2020.25
- Views 217
- Downloads 0
Effect of Crocus Sativus (Saffron) on Patients Suffering from Chemotherapy-Induced Painful Peripheral Neuropathy in Semnan Kosar Hospital
Background and Objective: One of the most important side effects of chemotherapy drugs is peripheral neuropathy, which is characterized by symptoms such as numbness, paresthesia, dysstasy, tingling or numbness of the li...
Neuro-Restorative Effect of Sertoli Cell Transplants in a Rat Model of Amyloid Beta Toxicity
Alzheimer’s disease (AD) is a degenerative nerve disease which adversely affects memory and learning skills. Currently, there is no disease-modifying therapeutic approach for AD. However, a growing body of literature s...
The Impact of Neurofeedback Training on Anxiety Reduction: A Case Study on a Retired Elite Powerlifting Athlete
Background and Aim: Retirement is a stressful situation that most employed persons may experiencing that. Career termination among elite athletes can produce more pressure on them, because they experience this situation...
Anti-Neuroinflammatory Effects of Sertoli Cells Improve Motor Activities and Striatal Volume in Rat Model of Huntington Disease
Introduction: Huntington’s disease (HD) is a genetically heritable disorder, linked with continuing cell loss and degeneration mostly in the striatum. Currently, cell therapy approaches in HD have essentially been focus...
Is this the way to Stop some of the Post Traumatic Effects of Brain Injury? Effects of Dextromethorphan on the Neurological Scores and Blood Brain Barrier after a Traumatic Brain Injury in Male Rat
Introduction: Dextromethorphan (DM), a sigma receptor agonist and NMDA receptor antagonist, protects neurons from glutamate excitotoxicity, hypoxia and ischemia, and inhibits microglial activation Therefore, in this stu...