Evidence for Locus Coeruleus-Norepinephrine System Abnormality in Military Posttraumatic Stress Disorder Revealed by Neuromelanin-Sensitive Magnetic Resonance Imaging.

Background: The complex neurobiology of posttraumatic stress disorder (PTSD) calls for the characterization of specific disruptions in brain functions that require targeted treatment. One such alteration could be an overactive locus coeruleus (LC)-norepinephrine system, which may be linked to hyperarousal symptoms, a characteristic and burdensome aspect of the disorder.

Methods: Study participants were Canadian Armed Forces veterans with PTSD related to deployment to combat zones (n = 34) and age- and sex-matched healthy control participants (n = 32).

65 years of research on dopamine's role in classical fear conditioning and extinction: A systematic review.

Dopamine, a catecholamine neurotransmitter, has historically been associated with the encoding of reward, whereas its role in aversion has received less attention. Here, we systematically gathered the vast evidence of the role of dopamine in the simplest forms of aversive learning: classical fear conditioning and extinction. In the past, crude methods were used to augment or inhibit dopamine to study its relationship with fear conditioning and extinction.

Repeated but Not Single Administration of Ketamine Prolongs Increases of the Firing Activity of Norepinephrine and Dopamine Neurons.

Background: Clinical studies have shown that the rapid antidepressant effect of the glutamate N-methyl-D-aspartate receptor antagonist ketamine generally disappears within 1 week but can be maintained by repeated administration. Preclinical studies showed that a single ketamine injection immediately increases the firing and burst activity of norepinephrine (NE) neurons, but not that of serotonin (5-HT) neurons. It also enhances the population activity of dopamine (DA) neurons.

Long-term administration of cariprazine increases locus coeruleus noradrenergic neurons activity and serotonin receptor neurotransmission in the hippocampus.

Background: Cariprazine, the novel dopamine (DA) D-preferring D/D and serotonin (5-HT) receptor partial agonist, has activity as an adjunctive therapy in major depressive disorder (MDD).

Aims: This study aims to investigate the effects of chronic cariprazine administration in combination with the selective serotonin reuptake inhibitor escitalopram on the activity of monoaminergic systems.

Methods: Rats received cariprazine alone and in adjunct to escitalopram for 2 and 14 days and the firing activity of dorsal raphe nucleus 5-HT, locus coeruleus norepinephrine (NE) and ventral tegmental area DA neurons was assessed.

Serotonin-2B receptor antagonism increases the activity of dopamine and glutamate neurons in the presence of selective serotonin reuptake inhibition.

Previous research has implicated the serotonin-2B (5-HT) receptor as a possible contributor to the antidepressant-like response. Aripiprazole has been successfully used in combination with selective serotonin reuptake inhibitors (SSRIs) in treatment-resistant depression and it, among all receptors, exhibits the highest affinity for the 5-HT receptor. However, the potential contribution of such an antagonistic action on 5-HT receptors in the context of adjunct therapy is not known.

Binge eating and social anxiety in treatment-seeking adolescents with eating disorders or severe obesity.

Purpose: Binge eating is a common behavior in children and adolescents who suffer from either eating disorders (EDs) or from severe obesity. The purpose of the current study was to explore the association between social anxiety and binge eating and compare prevalence rates of social anxiety between youth with severe obesity or EDs who did or did not engage in binge eating.

Methods: Retrospective data on treatment-seeking youth's (n = 490) eating behaviors and social anxiety at assessment were analyzed.