Peripheral effects of vagus nerve stimulation on anxiety and extinction of conditioned fear in rats.

Vagus nerve stimulation (VNS) enhances extinction of conditioned fear in rats. Previous findings support the hypothesis that VNS effects on extinction are due to enhanced consolidation of extinction memories through promotion of plasticity in extinction-related brain pathways however, alternative explanations are plausible. According to one hypothesis, VNS may produce a hedonic effect and enhance extinction through counter-conditioning.

Vagus nerve stimulation promotes generalization of conditioned fear extinction and reduces anxiety in rats.

Background: Exposure-based therapies are used to treat a variety of trauma- and anxiety-related disorders by generating successful extinction following cue exposure during treatment. The development of adjuvant strategies that accelerate extinction learning, improve tolerability, and increase efficiency of treatment could increase the efficacy of exposure-based therapies. Vagus nerve stimulation (VNS) paired with exposure can enhance fear extinction, in rat models of psychiatric disorders, and chronic administration of VNS reduces anxiety in rats and humans.

Vagus nerve stimulation as a tool for enhancing extinction in exposure-based therapies.

Rationale: Emotionally traumatic experiences can lead to maladaptive memories that are enduring and intrusive. The goal of exposure-based therapies is to extinguish conditioned fears through repeated, unreinforced exposures to reminders of traumatic events. The extinction of conditioned fear depends upon the consolidation of new memories made during exposure to reminders.

Cannabinoid Receptor 1 Gene by Cannabis Use Interaction on CB1 Receptor Density.

Because delta-9-tetrahydrocannabinol (THC), the primary psychoactive ingredient in cannabis, binds to cannabinoid 1 (CB1) receptors, levels of CB1 protein could serve as a potential biomarker for response to THC. To date, available techniques to characterize CB1 expression and function are limited. In this study, we developed an assay to quantify CB1 in lymphocytes to determine how it relates to cannabis use in 58 daily cannabis users compared with 47 nonusers.

Using the Single Prolonged Stress Model to Examine the Pathophysiology of PTSD.

The endurance of memories of emotionally arousing events serves the adaptive role of minimizing future exposure to danger and reinforcing rewarding behaviors. However, following a traumatic event, a subset of individuals suffers from persistent pathological symptoms such as those seen in posttraumatic stress disorder (PTSD). Despite the availability of pharmacological treatments and evidence-based cognitive behavioral therapy, a considerable number of PTSD patients do not respond to the treatment, or show partial remission and relapse of the symptoms.

NMDA receptor antagonism with MK-801 impairs consolidation and reconsolidation of passive avoidance conditioning in adolescent rats: evidence for a state dependent reconsolidation effect.

The characteristics of memory consolidation, reconsolidation, and state dependency have received considerable attention for many years. Three experiments examined the effects of the NMDA antagonist MK-801 on these phenomena in adolescent rats using passive avoidance conditioning. Experiment 1 demonstrated that immediate post-training administration of MK-801 produced a consolidation impairment at postnatal day 37.