Evaluation of the effects of L-Theanine on neurobehavior in an adult male Sprague-Dawley Rat Model of PTSD

Post-traumatic stress disorder (PTSD) continues to be one of the most common mental health disorders in the United States and may occur in response to traumatic experiences. Currently, there are no interventions that prevent the development of PTSD. L-Theanine (L-Th), a major compound in green tea has been found to decrease anxiety and prevent memory impairment and may have potential effects in the prevention of PTSD. Sixty rats were divided into six experimental groups: control vehicle, control L-Th, control naïve, PTSD vehicle, PTSD Pre-L-Th (prophylactic), PTSD Post-L-Th (non-prophylactic). PTSD was induced by a 3-day restraint/tail shock stress model. The effects of L-Th on neurobehavior were evaluated by Elevated Plus-Maze (EPM), Morris Water Maze (MWM), and Forced Swim Test (FST). Our study found that the total food intake weight of PTSD Pre-L-Th (prophylactic) rats were significantly increased compared to that of PTSD vehicle rats (p = .04). Administration of L-Th 24 hours before the initial PTSD event or for 10 days following the last PTSD stress event did not statistically improve mean open arm exploration on the EPM, spatial memory, and learning in the MWM or behavioral despair measured by the FST (p > 0.05). Although the 3-day restraint/tail shock stress model caused stress in the rodents, it did not produce reported PTSD-like anxiety and depression or spatial memory loss. The effect of Pre-L-Th or Post-L-Th treatment, on the neurobehavioral functions could not be effectively evaluated. However, this study provides a foundation for future studies to try different rodent PTSD models to induce PTSD-like neurobehavioral impairments to explore dosage, frequency, as well as the duration of L-Th administration before and/or after the post-traumatic event. The 3-day restraint/tail shock stress model caused stress in the rodents, Pre-L-Theanine treatment preconditioned the PTSD rats to endure stress

Effects of Tetrahydropalmatine (THP) on PTSD-induced Changes in Rat Neurobehavior

The purpose of this study was to investigate tetrahydropalmatine (THP), a major compound in Corydalis yanhusuo WT Wang (Family: Papaveraceae) and its effects on PTSD induced neurobehavior in the rodent model. The aims were to determine the effects of THP on anxiety, locomotion, and memory. A prospective experimental between groups design was used. Eighty rats were randomly divided into two groups, non-stressed and stressed. They were then randomly subdivided into four groups: control, THP, midazolam, or THP and midazolam. The behavioral component was evaluated using the elevated plus maze (EPM) and Morris water maze (MWM) in a restraint/shock stress model. Data analysis was performed using a two-tailed Multivariate Analysis of Variance (MANOVA) and LSD post-hoc test. There were significant differences in anxiety between the groups (P<0.05). The PTSD stressed rat groups had significantly reduced time on the open arms of the EPM demonstrating significant increased anxiety compared to the control nonstressed groups. Data pertaining to the MWM did not demonstrate statistical significance. While a one-time dose of THP was insufficient in providing a significant decrease in anxiety, a multi-dose regimen may yield more effective results. Future experiments should evaluate a multi-dose or prophylactic regimen

Investigation of Effects of L-Theanine on PTSD-induced Changes in Rat Neurobehavior

Post-traumatic stress disorder (PTSD) is a devastating neuropsychological disorder that may develop in response to traumatic experiences. Symptoms include anxiety, hypervigilance, memory deficits, and depression. We investigated L-Theanine on neurobehavioral effects in a PTSD rodent model. Evaluation of the effects of L-Theanine as a sole agent and in combination with midazolam on neurobehavior was analyzed using the Elevated Plus-Maze, Morris Water Maze, and Forced Swim Test. Statistical analysis consisted of comparison of PTSD symptoms in PTSD vs. non-stressed groups. Data regarding weight gain between the 40 control (non-stressed) and 40 PTSD (stressed) rats were significantly different (p < 0.001), where the control rats gained an average of 55.4 grams compared to 37.4 grams for the PTSD rats over the 10 post stress days. This research did not show statistical significance with single dose administration of L-Theanine or in combination with midazolam. However, the theoretic framework and Post-Traumatic Stress Disease Induction Model were validated based on this research. This study establishes a solid framework for future investigation of PTSD treatments. Future studies of L-Theanine and other herbal therapies may use an extended dosing period to obtain a steady state for the period of time needed to alter neurobiology

Effects of L-Theanine on Posttraumatic Stress Disorder Induced Changes in Rat Brain Gene Expression

Posttraumatic stress disorder (PTSD) is characterized by the occurrence of a traumatic event that is beyond the normal range of human experience. The future of PTSD treatment may specifically target the molecular mechanisms of PTSD. In the US, approximately 20% of adults report taking herbal products to treat medical illnesses. L-theanine is the amino acid in green tea primarily responsible for relaxation effects. No studies have evaluated the potential therapeutic properties of herbal medications on gene expression in PTSD. We evaluated gene expression in PTSD-induced changes in the amygdala and hippocampus of Sprague-Dawley rats. The rats were assigned to PTSD-stressed and nonstressed groups that received either saline, midazolam, L-theanine, or L-theanine + midazolam. Amygdala and hippocampus tissue samples were analyzed for changes in gene expression. One-way ANOVA was used to detect significant difference between groups in the amygdala and hippocampus. Of 88 genes examined, 17 had a large effect size greater than 0.138. Of these, 3 genes in the hippocampus and 5 genes in the amygdala were considered significant (P<0.05) between the groups. RT-PCR analysis revealed significant changes between groups in several genes implicated in a variety of disorders ranging from PTSD, anxiety, mood disorders, and substance dependence

Effects of pregabalin on neurobehavior in an adult male rat model of PTSD.

Posttraumatic stress disorder (PTSD) can be a very debilitating condition. Effective approaches to prevent and treat PTSD are important areas of basic science research. Pregabalin (PGB), a gabapentinoid derivative of γ-aminobutyric acid, possesses the potential to positively affect neurobehavioral changes associated with PTSD. Using a rodent model of PTSD, the aims of this study were to determine the effects of PGB as a possible prevention for the development of PTSD-like symptoms and its use as a possible treatment. A prospective, experimental, between groups design was used in conjunction with a three-day restraint/shock PTSD stress model. Sixty rats were randomly assigned between two groups, non-stressed and stressed (PTSD). Each of the main two groups was then randomly assigned into six experimental groups: control vehicle, control PGB, control naïve, PTSD vehicle, PTSD Pre-PGB (prophylactic), PTSD Post-PGB (non-prophylactic). The neurobehavioral components of PTSD were evaluated using the elevated plus maze (EPM), Morris water maze (MWM), and forced swim test (FST). Pregabalin administered 24 hours before the initial PTSD event or for 10 days following the last PTSD stress event did not statistically improve mean open arm exploration on the EPM, spatial memory, and learning in the MWM or behavioral despair measured by the FST (p > 0.05)