Impact of noradrenergic inhibition on neuroinflammation and pathophysiology in mouse models of Alzheimer's disease.

Norepinephrine (NE) modulates cognitive function, arousal, attention, and responses to novelty and stress, and it also regulates neuroinflammation. We previously demonstrated behavioral and immunomodulatory effects of beta-adrenergic pharmacology in mouse models of Alzheimer's disease (AD). The current studies were designed to block noradrenergic signaling in 5XFAD mice through (1) chemogenetic inhibition of the locus coeruleus (LC), (2) pharmacologic blocking of β-adrenergic receptors, and (3) conditional deletion of β1- or β2-adrenergic receptors (adrb1 or adrb2) in microglia.

Maintenance Intramuscular Ketamine-Assisted Psychotherapy, a Retrospective Chart Review of Efficacy, Adverse Events, and Dropouts from a Community Practice.

The use of ketamine and ketamine-assisted psychotherapy (KAP) for treatment of depression has grown dramatically, though much of these data are short term. The clinical profile of maintenance treatment remains poorly characterized. We assessed maintenance KAP for efficacy, tolerability, and reasons for dropout.

Impact of noradrenergic inhibition on neuroinflammation and pathophysiology in mouse models of Alzheimer's disease.

Norepinephrine (NE) modulates cognitive function, arousal, attention, and responses to novelty and stress, and also regulates neuroinflammation. We previously demonstrated behavioral and immunomodulatory effects of beta-adrenergic pharmacology in mouse models of Alzheimer's disease (AD). The current studies were designed to block noradrenergic signaling in 5XFAD mice through chemogenetic inhibition of the locus coeruleus (LC), pharmacologic blocking of β-adrenergic receptors, and conditional deletion of β1- or β2-adrenergic receptors (adrb1 or adrb2) in microglia.

5-HT receptors in the nucleus accumbens constrain the rewarding effects of MDMA.

MDMA is a promising adjunct to psychotherapy and has well-known abuse liability, although less than other amphetamine analogs. While the reinforcing dopamine (DA)-releasing properties of MDMA are on par with methamphetamine (METH), MDMA is a far more potent serotonin (5-HT) releaser, via the 5-HT transporter (SERT). MDMA-mediated 5-HT release in a major reward center, the nucleus accumbens (NAc), drives prosocial behaviors via 5-HTR activation.

Mapping of catecholaminergic denervation, neurodegeneration, and inflammation in 6-OHDA-treated Parkinson's disease mice.

Efforts to develop disease-modifying treatments for Parkinson's disease (PD) have been hindered by the lack of animal models replicating all hallmarks of PD and the insufficient attention to extra-nigrostriatal regions pathologically critical for the prodromal appearance of non-motor symptoms. Among PD models, 6-hydroxydopamine (6-OHDA) infusion in mice has gained prominence since 2012, primarily focusing on the nigrostriatal region. This study characterized widespread tyrosine hydroxylase-positive neuron and fiber loss across the brain following a unilateral 6-OHDA (20 μg) infusion into the dorsal striatum.

Opioids Diminish the Placebo Antidepressant Response: A Post Hoc Analysis of a Randomized Controlled Ketamine Trial.

Background: The endogenous opioid system is thought to play a role in the placebo antidepressant response. A recent trial comparing the rapid antidepressant effects of ketamine versus placebo in surgical patients, some of whom were on chronic opioid therapy, revealed a substantial placebo effect. This finding provided an opportunity to test the hypothesis that opioid agonist exposure interacts with placebo antidepressant responses.

Cross-species brain-wide mapping reveals a conserved and coordinated network engaged by NAc DBS.

Nucleus accumbens (NAc) deep brain stimulation (DBS) has been increasingly explored as a treatment modality for refractory neuropsychiatric disorders. Uncovering the accumbens network that is engaged by DBS is a critical step forward in understanding how modulating this important node impacts the broader mesocorticolimbic circuit. Using whole-brain clearing and unbiased, brain-wide neural activity mapping, we found that NAc DBS increases neural activity in a coordinated mesocorticolimbic network in mice.

Prevalence and characteristics of preoperative patients with depression.

Background: Within the perioperative period, depression-related diagnoses are associated with postoperative complications. We developed a perioperative depression screening programme to assess disease prevalence and feasibility for intervention.

Methods: Adult patients in multiple surgical departments at a single academic centre were screened for depression via the electronic health record patient portal or preoperative anaesthesia clinic before surgery, using the Patient Health Questionnaire (PHQ)-2 and -8.

Opioid receptor expressing neurons of the central amygdala gate behavioral effects of ketamine in mice.

Ketamine has anesthetic, analgesic, and antidepressant properties which may involve multiple neuromodulatory systems. In humans, the opioid receptor (OR) antagonist naltrexone blocks the antidepressant effect of ketamine. It is unclear whether naltrexone blocks a direct effect of ketamine at ORs, or whether normal functioning of the OR system is required to realize the full antidepressant effects of treatment.

Expectancy Effects in Psychedelic Trials.

Clinical trials of psychedelic compounds like psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltrptamine (DMT) have forced a reconsideration of how nondrug factors, such as participant expectations, are measured and controlled in mental health research. As doses of these profoundly psychoactive substances increase, so does the difficulty in concealing the treatment condition in the classic double-blind, placebo-controlled trial design. As widespread public enthusiasm for the promise of psychedelic therapy grows, so do questions regarding whether and how much trial results are biased by positive expectancy.

Randomized trial of ketamine masked by surgical anesthesia in patients with depression.

Ketamine may have antidepressant properties, but its acute psychoactive effects complicate successful masking in placebo-controlled trials. We present a single-center, parallel-arm, triple-masked, randomized, placebo-controlled trial assessing the antidepressant efficacy of intravenous ketamine masked by surgical anesthesia (ClinicalTrials.gov, NCT03861988).

Ketamine's acute effects on negative brain states are mediated through distinct altered states of consciousness in humans.

Ketamine commonly and rapidly induces dissociative and other altered states of consciousness (ASCs) in humans. However, the neural mechanisms that contribute to these experiences remain unknown. We used functional neuroimaging to engage key regions of the brain's affective circuits during acute ketamine-induced ASCs within a randomized, multi-modal, placebo-controlled design examining placebo, 0.

An orexigenic subnetwork within the human hippocampus.

Only recently have more specific circuit-probing techniques become available to inform previous reports implicating the rodent hippocampus in orexigenic appetitive processing. This function has been reported to be mediated at least in part by lateral hypothalamic inputs, including those involving orexigenic lateral hypothalamic neuropeptides, such as melanin-concentrating hormone. This circuit, however, remains elusive in humans.

Therapeutic mechanisms of psychedelics and entactogens.

Recent clinical and preclinical evidence suggests that psychedelics and entactogens may produce both rapid and sustained therapeutic effects across several indications. Currently, there is a disconnect between how these compounds are used in the clinic and how they are studied in preclinical species, which has led to a gap in our mechanistic understanding of how these compounds might positively impact mental health. Human studies have emphasized extra-pharmacological factors that could modulate psychedelic-induced therapeutic responses including set, setting, and integration-factors that are poorly modelled in current animal experiments.

UNRAVELing the synergistic effects of psilocybin and environment on brain-wide immediate early gene expression in mice.

The effects of context on the subjective experience of serotonergic psychedelics have not been fully examined in human neuroimaging studies, partly due to limitations of the imaging environment. Here, we administered saline or psilocybin to mice in their home cage or an enriched environment, immunofluorescently-labeled brain-wide c-Fos, and imaged iDISCO+ cleared tissue with light sheet fluorescence microscopy (LSFM) to examine the impact of environmental context on psilocybin-elicited neural activity at cellular resolution. Voxel-wise analysis of c-Fos-immunofluorescence revealed clusters of neural activity associated with main effects of context and psilocybin-treatment, which were validated with c-Fos cell density measurements.

The effects of ketamine on symptoms of depression and anxiety in real-world care settings: A retrospective controlled analysis.

Introduction: Ketamine intravenous therapy (KIT) appears effective for treating depression in controlled trials testing a short series of infusions. A rapidly proliferating number of clinics offer KIT for depression and anxiety, using protocols without a strong evidence basis. Controlled comparison of mood and anxiety from real-world KIT clinics, and the stability of outcomes, is lacking.

UNRAVELing the synergistic effects of psilocybin and environment on brain-wide immediate early gene expression in mice.

The effects of context on the subjective experience of serotonergic psychedelics have not been fully examined in human neuroimaging studies, partly due to limitations of the imaging environment. Here, we administered saline or psilocybin to mice in their home cage or an enriched environment, immunofluorescently-labeled brain-wide c-Fos, and imaged cleared tissue with light sheet microscopy to examine the impact of context on psilocybin-elicited neural activity at cellular resolution. Voxel-wise analysis of c-Fos-immunofluorescence revealed differential neural activity, which we validated with c-Fos cell density measurements.

A Protocol for Reducing Intensive Care Utilization After Craniotomy: A 3-Year Assessment.

Background: Craniotomy patients have traditionally received intensive care unit (ICU) care postoperatively. Our institution developed the "Non-Intensive CarE" (NICE) protocol to identify craniotomy patients who did not require postoperative ICU care.

Objective: To determine the longitudinal impact of the NICE protocol on postoperative length of stay (LOS), ICU utilization, readmissions, and complications.

Cervical sympathectomy to treat cerebral vasospasm: a scoping review.

Background/importance: Delayed cerebral ischemia (DCI) is the second-leading cause of death and disability in patients with aneurysmal subarachnoid hemorrhage (aSAH), and is associated with cerebral arterial vasospasm (CAV). Current treatments for CAV are expensive, invasive, and have limited efficacy. Cervical sympathetic block (CSB) is an underappreciated, but potentially highly effective therapy for CAV.

Modulation of 5-HT release by dynorphin mediates social deficits during opioid withdrawal.

Social isolation during opioid withdrawal is a major contributor to the current opioid addiction crisis. We find that sociability deficits during protracted opioid withdrawal in mice require activation of kappa opioid receptors (KORs) in the nucleus accumbens (NAc) medial shell. Blockade of release from dynorphin (Pdyn)-expressing dorsal raphe neurons (DR), but not from NAc neurons, prevents these deficits in prosocial behaviors.

Anesthetic-Induced Intraoperative Dream Associated With Remission of a Psychiatric Disorder: A Case Report.

Trauma is associated with debilitating acute and posttraumatic stress disorders, which have limited treatment options. We report on a patient undergoing surgical hand repair after a recent knife attack who experienced vivid dreaming and subsequent remission of acute stress disorder. After local anesthesia with propofol sedation she recalled a dream wherein she relived the attack, sought medical care, completed surgery, and returned home with a healed hand.

Great Expectations: recommendations for improving the methodological rigor of psychedelic clinical trials.

Rationale: Psychedelic research continues to garner significant public and scientific interest with a growing number of clinical studies examining a wide range of conditions and disorders. However, expectancy effects and effective condition masking have been raised as critical limitations to the interpretability of the research.

Objective: In this article, we review the many methodological challenges of conducting psychedelic clinical trials and provide recommendations for improving the rigor of future research.