Post-traumatic Stress Disorder In Mice Research Articles

Psychopharmacological interaction of alcohol and posttraumatic stress disorder: Effective action of naringin

Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) are prevalently co-occurring, important risk factors for a broad array of neuropsychiatric diseases. To date, how these two contrastive concomitant pairs increase the risk of neuropsychiatric states, notably exacerbating PTSD-related symptoms, remains unknown. Moreover, pharmacological interventions with agents that could reverse PTSD-AUD comorbidity, however, remained limited. Hence, we investigated the neuroprotective actions of naringin in mice comorbidly exposed to PTSD followed by repeated ethanol (EtOH)-induced AUD. Following a 7-day single-prolong-stress (SPS)-induced PTSD in mice, binge/heavy drinking, notably related to AUD, was induced in the PTSD mice with every-other-day ethanol (2 g/kg, p.o.) administration, followed by daily treatments with naringin (25 and 50 mg/kg) or fluoxetine (10 mg/kg), from days 8–21. PTSD-AUD-related behavioral changes, alcohol preference, hypothalamic-pituitary-adrenal (HPA)-axis dysfunction-induced neurochemical alterations, oxidative/nitrergic stress, and inflammation were examined in the prefrontal-cortex, striatum, and hippocampus. PTSD-AUD mice showed aggravated anxiety, spatial-cognitive, social impairments and EtOH intake, which were abated by naringin, similar to fluoxetine. Our assays on the HPA-axis showed exacerbated increased corticosterone release and adrenal hypertrophy, accompanied by marked dopamine and serotonin increase, with depleted glutamic acid decarboxylase enzyme in the three brain regions, which naringin, however, reversed, respectively. PTSD-AUD mice also showed increased TNF-α, IL-6, malondialdehyde and nitrite levels, with decreased antioxidant elements in the prefrontal-cortex, striatum, and hippocampus compared to SPS-EtOH-mice, mainly exacerbating catalase and glutathione decrease in the hippocampus relative SPS-mice. These findings suggest that AUD exacerbates PTSD pathologies in different brain regions, notably comprising neurochemical dysregulations, oxidative/nitrergic and cytokine-mediated inflammation, with HPA dysfunction, which were, however, revocable by naringin.

Diosgenin reverses posttraumatic stress disorder in mice by augmenting neurochemical release and inhibiting HPA axis dysfunction, oxidative stress, and neuroinflammation

Post-traumatic stress disorder (PTSD) is a mental disorder linked to neurochemical, hypothalamic-pituitary-adrenal (HPA)-axis dysregulations, inflammatory and pro-oxidant challenges in response to traumatic events. It is one of the leading causes of neurocognitive declines, hence prompting the need for a pharmacological intervention. However, the impact of diosgenin, a naturally occurring steroidal saponin with adaptogenic-like action, on PTSD-induced neuropsychiatric disturbances and its underlying mechanisms are unknown. In this study, we investigated the outcome of diosgenin treatment in a multimodal traumatic, single prolonged stress (SPS)-induced PTSD in mice. Following the SPS-induced 7 days of PTSD, mice (n = 9) were thereafter treated with diosgenin (25 and 50 mg/kg) or fluoxetine (10 mg/kg) orally from days 8–20 (14 days). Locomotory, cognitive-, depressive- and anxiety-like behaviors were investigated. We assayed for changes in adrenal weight, serum glucose and corticosterone concentrations. Neurochemical, inflammatory, oxido-nitrergic dysfunctions and monoamine oxidase-B and acetylcholinesterase activities, were measured in the striatum, prefrontal-cortex and hippocampus. The results revealed that the SPS challenge inhibited locomotor, spatial/non-spatial memory functions, increased anxiety and depressive-like features, which were reversed by diosgenin. Diosgenin reduced SPS-induced increased monoamine oxidase-B, acetylcholinesterase activities, TNF-α, IL-6, malondialdehyde and nitrite levels in the striatum, prefrontal-cortex and hippocampus. Antioxidants such as glutathione, superoxide-dismutase, and catalase levels in SPS-mice brains were increased by diosgenin. Moreover, diosgenin attenuated SPS-induced hyper-HPA-axis mediation of PTSD by decreasing serum corticosterone, glucose levels and adrenal gland hypertrophy. Herewith, we suggest that diosgenin convenes adaptogenic-like protection against mice exposed to PTSD by enhancing antioxidant machinery, neurochemical modulations, and inhibition of oxido-nitrergic, inflammatory, and HPA-axis dysfunctions.

Anshen Dingzhi prescription in the treatment of PTSD in mice: Investigation of the underlying mechanism from the perspective of hippocampal synaptic function

BackgroundAnshen Dingzhi prescription (ADP) is an important prescription for the treatment of mental diseases in traditional Chinese medicine and is widely used to treat neuropsychiatric disorders. PurposeTo explore the ameliorative effect of ADP on post-traumatic stress disorder (PTSD)-like behaviors in mice and determine the underlying mechanism. MethodsThe constituents of ADP were analyzed by UPLC–Q-TOF/MS. The PTSD-like behaviors of mice subjected to single prolonged stress (SPS) were evaluated using behavioral tests. Potential pathological changes in the hippocampus were assessed by hematoxylin and eosin (H&E) staining. Western blotting and immunohistochemistry (IHC) were employed to detect the expression of proteins involved in relevant signaling pathways. ResultsFive quality control markers (ginsenoside Rg1, ginsenoside Rb1, tenuifolin, poricoic acid B, and α-asarone) were detected in the ADP solution. The ginsenoside Rg1 content in ADP was found to be 0.114 mg/g. Mice subjected to SPS showed obvious fear generalization and anxiety-like behaviors. ADP treatment prevented the behavioral changes caused by exposure to SPS. Compared with control animals, the number of normal pyramidal cells in the hippocampal CA1 region of mice exposed to SPS was decreased and the number of degenerating pyramidal cells was increased; however, ADP administration could counteract these effects. Furthermore, the protein expression of BDNF, p-TrkB, μ-calpain, PSD95, GluN2A, GluA1, p-AKT, p-mTOR, and ARC was decreased, while that of PTEN and GluN2B was increased in the hippocampus of mice subjected to SPS compared with that in control animals; however, these changes in protein expression were reversed following ADP treatment. Importantly, the ameliorative effect of ADP on PTSD-like behaviors and synaptic protein expression were inhibited by rapamycin administration. ConclusionsADP administration improves PTSD-like behaviors in mice and this effect may be mediated through an mTOR-dependent improvement in synaptic function in the hippocampus.

Valeriana jatamansi Jones ex Roxb. Against Post-Traumatic Stress Disorder, Network Pharmacological Analysis, and In Vivo Evaluation.

Zhi zhu xiang (ZZX) is the root and rhizome of Valeriana jatamansi Jones ex Roxb. Recent studies have shown that ZZX can exert antianxiety, antidepressant, and sedative effects. Because post-traumatic stress disorder (PTSD) is similar to depression and anxiety in terms of its etiology, pathogenesis, and clinical manifestations, it is possible that ZZX may also be useful for the prevention and treatment of PTSD. In this study, a mouse model of PTSD was established and used to study the pharmacological action of a 95% ethanol extract of ZZX on PTSD via a series of classic behavioral tests. We found that a 95% ethanol extract of ZZX was indeed effective for relieving the symptoms of PTSD in mice. Moreover, network pharmacology analysis was used to predict the potential active ingredients, targets, and possible pathways of ZZX in the treatment of PTSD. The neurotransmitter system, the hypothalamic–pituitary–adrenal (HPA) axis, and the endocannabinoid (eCB) system were identified to be the most likely pathways for anti-PTSD action in ZZX. Due to the lack of a falsification mechanism in network pharmacology, in vivo tests were carried out in mice, and the expression levels of neurotransmitters, hormones, and genes of key targets were detected by enzyme-linked immunosorbent assay and real-time PCR to further verify this inference. Analysis showed that the levels of norepinephrine, 5-hydroxytryptamine, and glutamic acid were increased in the hippocampus, prefrontal cortex, and amygdala of PTSD mice, while the levels of dopamine and γ-aminobutyric acid were decreased in these brain regions; furthermore, ZZX could restore the expression of these factors, at least to a certain extent. The levels of adrenocorticotropic hormone, corticosterone, and corticotropin-releasing hormone were increased in these different brain regions and the serum of PTSD mice; these effects could be reversed by ZZX to a certain extent. The expression levels of cannabinoid receptor 1 and diacylglycerol lipase α mRNA were decreased in PTSD mice, while the levels of fatty acid amide hydrolase and monoacylglycerol lipase mRNA were increased; these effects were restored by ZZX to a certain extent. In conclusion, our findings suggest that ZZX may provide new therapeutic pathways for treating PTSD by the regulation of neurotransmitters, the HPA, and expression levels of eCB-related genes in the brain.

102 Single-Prolonged Stress as a Model of PTSD in Mice: Effects on Sleep and Anxiety

Abstract Introduction Sleep problems are common in humans with post-traumatic stress disorder (PTSD). Rapid eye movement (REM) sleep is involved in processing emotional memories; it is often disrupted in those with PTSD, and may be related to increased anxiety. Single prolonged stress (SPS) is a protocol used to model PTSD in rats, however little is known about how this model impacts sleep in mice. Prior research suggests SPS produces short term disturbances in REM sleep and increases in anxiety-like behavior, but further validation of this model is needed to understand how SPS impacts sleep and anxiety-like behaviors in mice specifically, as they have greater potential for transgenic manipulation Methods C57BL6/J mice underwent a SPS protocol in which they were tube-restrained for 2 hours, followed by a 15 minute forced swim in a group, ether exposure until loss of consciousness, and 10 days of social isolation. Following SPS, mice were tested for anxiety-like behavior in a light-dark box and sleep was measured from surgically implanted EEG and EMG leads. Time spent in wake, REM sleep, and non-REM sleep was quantified for 24 continuous hours in SPS and Control mice. Results There were no significant effects of SPS on the amount of time spent in any vigilance state, or in sleep-wake transitions. However, SPS-exposed mice showed significantly more anxiety-like behavior. EEG power spectra were analyzed in relevant frequency bands during each sleep state, and exploratory analyses were conducted Conclusion Minimal effects on sleep macroarchitecture were seen in mice 10 days after SPS. It is possible that sleep disturbances seen immediately after trauma exposure (such as in prior studies in rats) may have diminished over time. Further studies will need to include additional timepoints and analysis of sleep microarchitecture following SPS, and in other mouse models of PTSD, in order to more comprehensively examine changes in sleep. Support (if any) VA CDA #IK2 BX002712, Portland VA Research Foundation, Medical Research Foundation

Microglial deletion and inhibition alleviate behavior of post-traumatic stress disorder in mice

BackgroundAlteration of immune status in the central nervous system (CNS) has been implicated in the development of post-traumatic stress disorder (PTSD). However, the nature of overall changes in brain immunocyte landscape in PTSD condition remains unclear.MethodsWe constructed a mouse PTSD model by electric foot-shocks followed by contextual reminders and verified the PTSD-related symptoms by behavior test (including contextual freezing test, open-field test, and elevated plus maze test). We examined the immunocyte panorama in the brains of the naïve or PTSD mice by using single-cell mass cytometry. Microglia number and morphological changes in the hippocampus, prefrontal cortex, and amygdala were analyzed by histopathological methods. The gene expression changes of those microglia were detected by quantitative real-time PCR. Genetic/pharmacological depletion of microglia or minocycline treatment before foot-shocks exposure was performed to study the role of microglia in PTSD development and progress.ResultsWe found microglia are the major brain immune cells that respond to PTSD. The number of microglia and ratio of microglia to immunocytes was significantly increased on the fifth day of foot-shock exposure. Furthermore, morphological analysis and gene expression profiling revealed temporal patterns of microglial activation in the hippocampus of the PTSD brains. Importantly, we found that genetic/pharmacological depletion of microglia or minocycline treatment before foot-shock exposure alleviated PTSD-associated anxiety and contextual fear.ConclusionOur results demonstrated a critical role for microglial activation in PTSD development and a potential therapeutic strategy for the clinical treatment of PTSD in the form of microglial inhibition.

BHLHE40 modulates post-traumatic stress disorder behaviors with the involvement of the PI3K/AKT signaling pathway.

Post-traumatic stress disorder (PTSD) is closely related to the exposure to traumatic events and results in the structural and functional changes of hippocampus. Human basic helix-loop-helix family member e40 (BHLHE40) was reported to be implicated with neuron maturity and neuronal differentiation. The present study aimed to reveal the role of BHLHE40 on single-prolonged stress (SPS) model of PTSD in mice. The morris water maze test, open field test and contextual fear test were conducted to assess memory deficits, anxiety-like behaviors, and freezing of mice. Western blot was performed to identify proteins and reveal their levels in hippocampal tissues. We found that mice receiving SPS exhibited increased anxiety-like behaviors, memory deficits, and prolonged freezing time. The protein levels of BHLHE40 were downregulated in the hippocampal tissues of SPS mice. SPS reduced the protein levels of glutamate receptors, while overexpression of BHLHE40 promoted glutamate receptor protein levels in SPS mice. Moreover, BHLHE40 overexpression activated the PI3K/AKT pathway. BHLHE40 overexpression ameliorated the SPS-induced PTSD-like behavioral deficits. Overall, BHLHE40 promotes glutamate receptor protein levels to ameliorate PTSD-like behaviors with the involvement of the PI3K/AKT pathway. This novel discovery may provide a potential target for the improvement of PTSD.

Protocols to Induce, Prevent, and Treat Post-traumatic Stress Disorder-like Memory in Mice: Optogenetics and Behavioral Approaches.

One of the cardinal features of post-traumatic stress disorder (PTSD) is a paradoxical memory alteration including both emotional hypermnesia for salient trauma-related cues and amnesia for the surrounding traumatic context. Interestingly, some clinical studies have suggested that contextual amnesia would causally contribute to the PTSD-related hypermnesia insofar as decontextualized, traumatic memory is prone to be reactivated in contexts that can be very different from the original traumatic context. However, most current animal models of PTSD-related memory focus exclusively on the emotional hypermnesia, i.e., the persistence of a strong fear memory, and do not distinguish normal (adaptive) from pathological (PTSD-like) fear memory, leaving unexplored the hypothetical critical role of contextual amnesia in PTSD-related memory formation, and thus challenging the development of innovative treatments. Having developed the first animal model that precisely recapitulates the two memory components of PTSD in mice (emotional hypermnesia and contextual amnesia), we recently demonstrated that contextual amnesia, induced by optogenetic inhibition of the hippocampus (dorsal CA1), is a causal cognitive process of PTSD-like hypermnesia formation. Moreover, the hippocampus-dependent contextualization of traumatic memory, by optogenetic activation of dCA1 in traumatic condition, prevents PTSD-like hypermnesia formation. Finally, once PTSD-like memory has been formed, the re-contextualization of traumatic memory by its reactivation in the original traumatic context normalizes this pathological fear memory. Revealing the key role of contextual amnesia in PTSD-like memory, this procedure opens a therapeutic perspective based on trauma contextualization and the underlying hippocampal mechanisms.

Short-term sleep deprivation immediately after contextual conditioning inhibits BDNF signaling and disrupts memory consolidation in predator odor trauma mice model of PTSD

Post-traumatic stress disorder (PTSD) is a debilitating neuropsychiatric illness affecting > 7 million people every year in the US. Recently, we have shown that the mouse model of predator odor trauma (POT) displayed contextual conditioning and core features of PTSD including sleep disturbances (hyperarousal) and retrieval of traumatic memories following exposure to objective reminders (re-experiencing). PTSD is a disorder of memory function. Since memory consolidation requires the expression of BDNF along with an activation of MAPK/pERK signaling pathway in limbic brain structures (hippocampus and amygdala) and sleep favors memory consolidation, we hypothesized that short-term sleep deprivation (SD, 3 h), immediately after contextual conditioning will attenuate molecular correlates of memory consolidation, sleep disturbances, and memory consolidation. We performed two experiments in adult male C57BL/6J mice to test our hypothesis. Experiment 1 determined the effects of SD on contextual conditioning and changes in sleep wakefulness. Experiment 2 determined the effects of SD on contextual conditioning-induced changes in the expression of BDNF and pERK in hippocampus and amygdala. SD immediately after contextual conditioning (POT + SD group) significantly attenuated sleep disturbances, memory retrieval, and expression of pERK and BDNF in the hippocampus and amygdala as compared to POT-SD group (no SD after contextual conditioning). No significant differences were observed between POT + SD, NOC-SD (no contextual conditioning + no SD), and NOC + SD (no contextual conditioning + SD) groups. Memory consolidation requires sleep and the expression of pERK and BDNF in hippocampus and amygdala immediately after contextual conditioning in POT model of PTSD in mice.

Brexpiprazole blocks post-traumatic stress disorder-like memory while promoting normal fear memory.

A cardinal feature of post-traumatic stress disorder (PTSD) is a long-lasting paradoxical alteration of memory with hypermnesia for salient traumatic cues and amnesia for peri-traumatic contextual cues. So far, pharmacological therapeutic approach of this stress-related disorder is poorly developed mainly because of the lack of animal model for this paradoxical memory alteration. Using a model that precisely recapitulates the two memory components of PTSD in mice, we tested if brexpiprazole, a new antipsychotic drug with pro-cognitive effects in rodents, may persistently prevent the expression of PTSD-like memory induced by injection of corticosterone immediately after fear conditioning. Acute administration of brexpiprazole (0.3 mg/kg) 7 days' post-trauma first blocks the expression of the maladaptive fear memory for a salient but irrelevant trauma-related cue. In addition, it enhances (with superior efficacy when compared to diazepam, prazosin, and escitalopram) memory for the traumatic context, correct predictor of the threat. This beneficial effect of brexpiprazole is overall maintained 1 week after treatment. In contrast brexpiprazole fully spares normal/adaptive cued fear memory, showing that the effect of this drug is specific to an abnormal/maladaptive (PTSD-like) fear memory of a salient cue. Finally, this treatment not only promotes the switch from PTSD-like to normal fear memory, but also normalizes most of the alterations in the hippocampal-amygdalar network activation associated with PTSD-like memory, as measured by C-Fos expression. Altogether, these preclinical data indicate that brexpiprazole could represent a new pharmacological treatment of PTSD promoting the normalization of traumatic memory.

Modeling of Post-Traumatic Stress Disorder in Mice: Nonlinear Relationship with the Strength of the Traumatic Event

The neurophysiological mechanisms of the development of post-traumatic stress disorder (PTSD) in humans remain poorly understood and require experimental investigation in animal models. We report here studies of variation in the range of conditions for the acquisition of PTSD in a learned fear model in mice using electrocutaneous shocks (ECS) as the stressful event. Use of different ECS application parameters showed that the severity of fear-induced and behavioral sensitization has a nonlinear relationship with the intensity of the traumatizing event. The optimum parameters for acquisition of PTSD are three shocks each of current 1.5 mA and duration 10 sec. The critical parameter is the number of ECS applied. Increases in the strength or duration of the traumatizing event did not lead to more severe signs of PTSD. As the number of ECS increased further, the behavior of the mice stopped being homogeneous: some of the animals demonstrated marked PTSD-like behavior, while others showed no signs of PTSD at all. These results identify the effective conditions for acquisition of PTSD in a learned fear model in mice and the conditions for the occurrence of individual variability in the traumatizing event, points important for understanding the mechanisms forming PTSD.

Preliminary Study on the Preventive Effect of Ginsenoside Rg1 on Posttraumatic Stress Disorder in Mice

Preliminary Study on the Preventive Effect of Ginsenoside Rg1 on Posttraumatic Stress Disorder in Mice

Investigating the role of nisoldipine in foot-shock-induced post-traumatic stress disorder in mice.

This study was designed to investigate the effectiveness of nisoldipine, an L-type voltage-sensitive calcium channel blocker, to ameliorate anxiety and fear response in a mouse model of post-traumatic stress disorder (PTSD). Acute trauma was induced in Swiss albino mice in a 2-day electric foot-shock paradigm consisting of 15 intermittent foot-shocks of 0.8 mA intensity, 10-s duration and 10-s intershock interval, during 5 min, followed by 3 weekly situational reminders, that is, once per week in the same context on three successive weeks. PTSD-induced behavioral changes were assessed using actophotometer, open-field, social interaction test, and freezing behavior. Biochemically, the serum corticosterone levels were estimated. Electric foot-shock and situational reminders produced behavioral alterations and decreased corticosterone levels, assessed on the 21st day following the traumatic event. Administration of sertraline (Ser 15 mg/kg), a selective serotonin reuptake inhibitor (SSRI) and nisoldipine (20 and 40 mg/kg), significantly attenuated the foot-shock-trauma-induced behavioral changes along with normalization of the corticosterone levels. It may be concluded that nisoldipine produces beneficial effects in re-establishing behavioral alterations, which may be due to normalization of reduced corticosterone levels in PTSD in mice.

The CRF1 receptor antagonist SSR125543 prevents stress-induced long-lasting sleep disturbances in a mouse model of PTSD: Comparison with paroxetine and d-cycloserine

The selective CRF1 (corticotropin releasing factor type 1) receptor antagonist SSR125543 has been previously shown to attenuate the long-term behavioral and electrophysiological effects produced by traumatic stress exposure in mice. Sleep disturbances are one of the most commonly reported symptoms by people with post-traumatic stress disorder (PTSD). The present study aims at investigating whether SSR125543 (10mg/kg/day/i.p. for 2 weeks) is able to attenuate sleep/wakefulness impairment induced by traumatic stress exposure in a model of PTSD in mice using electroencephalographic (EEG) analysis. Effects of SSR125543 were compared to those of the 5-HT reuptake inhibitor, paroxetine (10mg/kg/day/i.p.), and the partial N-methyl-d-aspartate (NMDA) receptor agonist, d-cycloserine (10mg/kg/day/i.p.), two compounds which have demonstrated clinical efficacy against PTSD. Baseline EEG recording was performed in the home cage for 6h prior to the application of two electric foot-shocks of 1.5mA. Drugs were administered from day 1 post-stress to the day preceding the second EEG recording session, performed 14 days later. Results showed that at day 14 post-stress, shocked mice displayed sleep fragmentation as shown by an increase in the occurrence of both non-rapid eye movement (NREM) sleep and wakefulness bouts. The duration of wakefulness, NREM and REM sleep were not significantly affected. The stress-induced effects were prevented by repeated administration of SSR125543, paroxetine and d-cycloserine. These findings confirm further that the CRF1 receptor antagonist SSR125543 is able to attenuate the deleterious effects of traumatic stress exposure.