Metoprolol decreases retention of fear memory and facilitates long-term depression in lateral amygdala

Stress and inflammation target dorsolateral prefrontal cortex function: Neural mechanisms underlying weakened cognitive control

Most mental disorders involve dysfunction of the dorsolateral prefrontal cortex (dlPFC), a recently evolved brain region that subserves working memory, abstraction and the thoughtful regulation of attention, action and emotion. For example, schizophrenia, depression, long-COVID and Alzheimer's disease are all associated with dlPFC dysfunction, with neuropathology often focused in layer III. The dlPFC has extensive top-down projections: e.g. to the posterior association cortices to regulate attention, and the subgenual cingulate cortex via the rostral and medial PFC to regulate emotional responses. However, the dlPFC is particularly dependent on arousal state, and is very vulnerable to stress and inflammation, which are etiological and/or exacerbating factors in most mental disorders. The cellular mechanisms by which stress and inflammation impact the dlPFC are a topic of current research, and are summarized in this review. For example, the layer III dlPFC circuits generating working memory-related neuronal firing have unusual neurotransmission, depending on NMDAR and nicotinic-α7R actions that are blocked under inflammatory conditions by kynurenic acid. These circuits also have unusual neuromodulation, with the molecular machinery to magnify calcium signaling in spines needed to support persistent firing, which must be tightly regulated to prevent toxic calcium actions. Stress rapidly weakens layer III connectivity by driving feedforward calcium-cAMP opening of potassium channels on spines. This is regulated by postsynaptic noradrenergic α2A-AR and mGluR3 signaling, but dysregulated by inflammation and/or chronic stress exposure, contributing to spine loss. Treatments that strengthen dlPFC, via pharmacological (the α2A-AR agonist, guanfacine) or rTMS manipulation, provide a rational basis for therapy.

Pharmacotherapy in the Management of Anxiety and Pain During Acute Coronary Syndromes and the Risk of Developing Symptoms of Posttraumatic Stress Disorder

Background Benzodiazepines and morphine are given during acute coronary syndromes (ACSs) to alleviate anxiety and pain, and β-blockers may also reduce pain. ACS may induce posttraumatic stress disorder (PTSD) symptoms (PTSS). When taken during trauma other than ACS, benzodiazepines increase the risk of PTSS, but it is unknown if benzodiazepines increase the risk of PTSS in ACS. We examined the effects of drug exposure during ACS on the development of PTSS. Methods and Results Study participants were 154 patients with a verified ACS. Baseline demographics, clinical variables, and psychological measures were obtained through a medical history, through a psychometric assessment, and from patient records, and used as covariates in linear regression analysis. Three months after ACS, the severity of PTSS was assessed with the Clinician-Administered PTSD Scale. During ACS, 37.7% of patients were exposed to benzodiazepines, whereas 72.1% were exposed to morphine and 88.3% were exposed to β-blockers, but only 7.1% were exposed to antidepressants. Eighteen (11.7%) patients developed clinical PTSD. Adjusting for all covariates, benzodiazepine use was significantly associated with the Clinician-Administered PTSD Scale total severity score (unstandardized coefficient B [SE], 0.589 [0.274]; partial r=0.18; P=0.032) and the reexperiencing subscore (B [SE], 0.433 [0.217]; partial r=0.17; P=0.047). Patients exposed to benzodiazepines had an almost 4-fold increased relative risk of developing clinical PTSD, adjusting for acute stress disorder symptoms (odds ratio, 3.75; 95% CI, 1.31-10.77). Morphine, β-blockers, and antidepressants showed no predictive value. Conclusions Notwithstanding short-term antianxiety effects during ACS, benzodiazepine use might increase the risk of ACS-induced PTSS with clinical significance, thereby compromising patients' quality of life and prognosis. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01781247.