Effects of psilocybin on body weight, body composition, and metabolites in male and female mice.

There is growing interest in the therapeutic potential of psilocybin for the treatment of a wide variety of medical problems, and even for the promotion of wellbeing among healthy individuals. Interestingly, among the many proposed indications, both obesity and anorexia nervosa (AN) have been discussed. However, the effect of psilocybin on appetitive behavior and metabolism is not well known. Here, we report the effects of psilocybin on body weight, intake and output, body composition, and metabolic function among lean male and female wild-type mice. In the days immediately following treatment, both male and female mice receiving a single intraperitoneal dose of psilocybin were consistently heavier than saline controls, with no effect of psilocybin on intake or output. Co-administration of the 5-HT2A/2C receptor antagonist ketanserin had no effect on this outcome. Body composition analysis revealed that psilocybin significantly increased lean and water mass among males, with a similar trend among females. A metabolic panel revealed increased creatine kinase (CK), aspartate aminotransferase (AST), and chloride among male and female psilocybin treated mice. Together, these findings begin to investigate the potential mechanisms of psilocybin's effects on body weight and metabolic measures. Such understanding will be critical for the safe, efficacious, and well-informed use of psilocybin in clinical and non-clinical settings.

Utility of preclinical models in the study of psilocybin - A comprehensive review.

Interest in the therapeutic potential of psilocybin across a broad range of neuropsychiatric disorders is rapidly expanding. Despite promising clinical data and tremendous public enthusiasm, complimentary basic and translational studies - which are critical for advancing our understanding of psilocybin's biological effects and promoting innovation - have been relatively few. As with all work involving the study of complex neuropsychopharmacology, the search for deeper understanding of biological mechanisms, and the need for nuanced behavioral analyses in the context of both normal and diseased states, the roles for preclinical models are clear. A systematic search of the literature identified 57 articles involving the study of psilocybin in preclinical rodent models. A comprehensive review and thematic analysis identified 4 broad areas of investigation - pharmacology, toxicity, effects on disease models, and molecular mechanisms - with pharmacology studies accounting for the majority. Though these papers represent a still remarkably small body of literature, several important conclusions can already be drawn, and several areas of high priority for future work can be identified.

Activity-based anorexia in adolescent female rats causes changes in brain mitochondrial dynamics.

Anorexia Nervosa (AN) is associated with a high rate of morbidity and mortality as well as a high rate of relapse. The molecular mechanisms underlying the progression of the disorder or the relapses are largely unknown. Patients with AN have been shown to have increased oxidative stress, but its involvement in the development in the disease is unknown. We have previously shown that adolescent female rats undergoing the activity-based anorexia (ABA) paradigm also show signs of oxidative stress. Due to their role in the release of reactive oxygen species (ROS), mitochondria are of high interest in diseases exhibiting oxidative stress. In this study, the impact of ABA on brain mitochondrial dynamics was examined. We found transient changes in the medial prefrontal cortex, hypothalamus, and hippocampus following 25% weight loss and changes in the amygdala at a 10-day weight recovery timepoint. These changes point towards damage in the mitochondria contributing to the oxidative stress.

Sex Chromosome Rearrangement Associated With Hormonal Abnormalities and Gender Dysphoria.

Although disorders arising from sex chromosome and sex steroid abnormalities are well characterized from the perspectives of endocrinology, dysmorphology, and reproductive health, relatively little is known about neuropsychiatric development, gender identity, incongruence, and dysphoria in the populations with these disorders. In this report, we describe the case of a 21-year-old gender nonbinary individual identified as male at birth who presented to an academic psychiatry consultation clinic because of life-long gender dysphoria. The patient was found to have a complex sex chromosomal rearrangement and associated hormonal abnormalities that may, at least in part, explain the patient's history. In addition to describing a novel genetic change, this case and the accompanying review of the existing literature highlight the need for an increased focus on the psychiatric perspective, and sex and gender issues in particular, among all patients with sex chromosome abnormalities and inborn errors of steroid metabolism.

Rat offspring's microbiota composition is predominantly shaped by the postnatal maternal diet rather than prenatal diet.

This study assessed the impact of maternal diet during pregnancy versus lactation on offspring gut microbiota. Sprague-Dawley dams were fed high fat (HF) or Chow diets during pregnancy, and their male offspring were raised by a different dam consuming the same or opposite diet (Chow-Chow, Chow-HF, HF-Chow, and HF-HF). Microbiota analysis showed that maternal lactation diet, rather than pregnancy diet, determined offspring microbiota profiles at weaning. Increased abundances of Turicibacter, Staphylococcus , and Ruminococcus were characteristic of chow lactation groups. Lactococcus , Streptococcus , and Parabacteroides were characteristic of HF lactation groups and positively correlated with offspring body weight.

Bipolar depression: a review of treatment options.

Bipolar depression (BD-D) is both common and incredibly challenging to treat. Even treated individuals with BD-D experience depression approximately 19% of the time, and subsyndromal depression an additional 18%. This stands in clear contrast to the approximately 10% of time spent in hypomania and 1% of time spent in mania. Despite this high illness burden, there remain relatively few treatment options approved by the US Food and Drug Administration for BD-D. Of the approved medications, four are second-generation antipsychotics (SGAs) and one is an SGA combined with an antidepressant. However, particularly when used long-term, antipsychotics can pose a significant risk of adverse effects, raising the clinical conundrum of weighing the risks associated with long-term antipsychotic use versus the risk of relapse when patients are off medications. Here, we review commonly used treatments for BD-D, including antipsychotics, classic mood stabilisers, electroconvulsive therapy and psychotherapy. We then address the somewhat controversial topic of antidepressant use in BD-D. Finally, we summarise emerging treatment options and highlight ongoing clinical trials. We hope this review will help compare the risks and benefits of several common and novel options for the treatment of patients with BD-D. In doing so, we also hope this review will aid the individualised selection of treatments based on each patient's history and treatment goals.

Fluoxetine and environmental enrichment similarly reverse chronic social stress-related depression- and anxiety-like behavior, but have differential effects on amygdala gene expression.

The adverse effects of stress on brain and behavior have long been known and well-studied, with abundant evidence linking stress to, among other things, mood and anxiety disorders. Likewise, many have investigated potential treatments for stress-related mood and anxiety phenotypes and demonstrated good response to standard antidepressant medications like selective serotonin reuptake inhibitors (SSRIs), as well as environmental manipulations like exercise or enrichment. However, the extent to which stress and various treatments act on overlapping pathways in the brain is less well understood. Here, we used a widely studied social defeat stress paradigm to induce a robust depression- and anxiety-like phenotype and chronic corticosterone elevation that persisted for at least 4 weeks in wild type male mice. When mice were treated with either the SSRI fluoxetine or an enriched environment, both led to similar behavioral recovery from social defeat. We then focused on the amygdala and assessed the effects of social defeat, fluoxetine, and enrichment on 168 genes broadly related to synaptic plasticity or oxidative stress. We found 24 differentially expressed genes in response to social defeat stress. Interestingly, fluoxetine led to broad normalization of the stress-induced expression pattern while enrichment led to expression changes in a separate set of genes. Together, this study provides additional insight into the chronic effects of social defeat stress on behavior and gene expression in the amygdala. The findings also suggest that, for a subset of genes assessed, fluoxetine and environmental enrichment have strikingly divergent effects on expression in the amygdala, despite leading to similar behavioral outcomes.

Vagal gut-brain signaling mediates amygdaloid plasticity, affect, and pain in a functional dyspepsia model.

Functional dyspepsia (FD) is associated with chronic gastrointestinal distress and with anxiety and depression. Here, we hypothesized that aberrant gastric signals, transmitted by the vagus nerve, may alter key brain regions modulating affective and pain behavior. Using a previously validated rat model of FD characterized by gastric hypersensitivity, depression-like behavior, and anxiety-like behavior, we found that vagal activity - in response to gastric distention - was increased in FD rats. The FD phenotype was associated with gastric mast cell hyperplasia and increased expression of corticotrophin-releasing factor (Crh) and decreased brain-derived neurotrophic factor genes in the central amygdala. Subdiaphragmatic vagotomy reversed these changes and restored affective behavior to that of controls. Vagotomy partially attenuated pain responses to gastric distention, which may be mediated by central reflexes in the periaqueductal gray, as determined by local injection of lidocaine. Ketotifen, a mast cell stabilizer, reduced vagal hypersensitivity, normalized affective behavior, and attenuated gastric hyperalgesia. In conclusion, vagal activity, partially driven by gastric mast cells, induces long-lasting changes in Crh signaling in the amygdala that may be responsible for enhanced pain and enhanced anxiety- and depression-like behaviors. Together, these results support a "bottom-up" pathway involving the gut-brain axis in the pathogenesis of both gastric pain and psychiatric comorbidity in FD.

Ankyrin-G Heterozygous Knockout Mice Display Increased Sensitivity to Social Defeat Stress.

The ANK3 locus has been repeatedly found to confer an increased risk for bipolar disorder. ANK3 codes for Ankyrin-G (Ank-G), a scaffold protein concentrated at axon initial segments, nodes of Ranvier, and dendritic spines, where it organizes voltage-gated sodium and potassium channels and cytoskeletal proteins. Mice with homozygous conditional knockout of Ank-G in the adult forebrain display hyperactivity and reduced anxiety-like behaviors, responsive to mood stabilizers. Their behavior switches to a depression-like phenotype when exposed to chronic social defeat stress (SDS), and then spontaneously reverts to baseline hyperactivity. Ank-G heterozygous conditional knockouts (Ank-G Het cKO) have not previously been characterized. Here, we describe the behavior of Ank-G Het cKO mice compared to littermate controls in the open field, elevated plus maze, and forced swim test, under both unstressed and stressed conditions. We found that Ank-G Het cKO is not significantly different from controls at baseline or after chronic SDS. The chronic stress-induced "depression-like" behavioral phenotype is persistent for at least 28 days and is responsive to fluoxetine. Strikingly, Ank-G Het cKO mice display increased sensitivity to a short duration SDS, which does not affect controls. The heterozygous Ank-G genetic model may provide novel insights into the role of Ank-G in the pathophysiology of stress sensitivity and "depression-like" phenotypes and could be useful for studying Ank-G-related gene-environment interactions.

Review and Consensus on Pharmacogenomic Testing in Psychiatry.

The implementation of pharmacogenomic (PGx) testing in psychiatry remains modest, in part due to divergent perceptions of the quality and completeness of the evidence base and diverse perspectives on the clinical utility of PGx testing among psychiatrists and other healthcare providers. Recognizing the current lack of consensus within the field, the International Society of Psychiatric Genetics assembled a group of experts to conduct a narrative synthesis of the PGx literature, prescribing guidelines, and product labels related to psychotropic medications as well as the key considerations and limitations related to the use of PGx testing in psychiatry. The group concluded that to inform medication selection and dosing of several commonly-used antidepressant and antipsychotic medications, current published evidence, prescribing guidelines, and product labels support the use of PGx testing for 2 cytochrome P450 genes (CYP2D6, CYP2C19). In addition, the evidence supports testing for human leukocyte antigen genes when using the mood stabilizers carbamazepine (HLA-A and HLA-B), oxcarbazepine (HLA-B), and phenytoin (CYP2C9, HLA-B). For valproate, screening for variants in certain genes (POLG, OTC, CSP1) is recommended when a mitochondrial disorder or a urea cycle disorder is suspected. Although barriers to implementing PGx testing remain to be fully resolved, the current trajectory of discovery and innovation in the field suggests these barriers will be overcome and testing will become an important tool in psychiatry.

The Care of Patients With Complex Mood Disorders.

This article focuses on some common dilemmas facing clinicians, patients, and families in managing the treatment of complicated mood disorders. Specifically, this article reviews the interaction of depressive states, including unipolar, bipolar, and mixed, with other adversities, including comorbid physical and psychological disorders, personality vulnerabilities, misuse of drugs and alcohol, and social and family problems. These issues are not always clearly differentiated from the depressive illness. Each of these adversities can worsen an existing mood disorder and influence the patient's resolve to persist with a treatment plan. Although this article is not focused strictly on treatment-resistant depression, these coexisting issues make depressive states harder to manage therapeutically. For brevity, the aim of this article has been limited to discussion of some complex situations that psychiatrists in general practice may encounter.

Maternal stressors and the developmental origins of neuropsychiatric risk.

The maternal environment during pregnancy is critical for fetal development and perinatal perturbations can prime offspring disease risk. Here, we briefly review evidence linking two well-characterized maternal stressors - psychosocial stress and infection - to increased neuropsychiatric risk in offspring. In the current climate of increasing obesity and globalization of the Western-style diet, maternal overnutrition emerges as a pressing public health concern. We focus our attention on recent epidemiological and animal model evidence showing that, like psychosocial stress and infection, maternal overnutrition can also increase offspring neuropsychiatric risk. Using lessons learned from the psychosocial stress and infection literature, we discuss how altered maternal and placental physiology in the setting of overnutrition may contribute to abnormal fetal development and resulting neuropsychiatric outcomes. A better understanding of converging pathophysiological pathways shared between stressors may enable development of interventions against neuropsychiatric illnesses that may be beneficial across stressors.

Nitrated meat products are associated with mania in humans and altered behavior and brain gene expression in rats.

Mania is a serious neuropsychiatric condition associated with significant morbidity and mortality. Previous studies have suggested that environmental exposures can contribute to mania pathogenesis. We measured dietary exposures in a cohort of individuals with mania and other psychiatric disorders as well as in control individuals without a psychiatric disorder. We found that a history of eating nitrated dry cured meat but not other meat or fish products was strongly and independently associated with current mania (adjusted odds ratio 3.49, 95% confidence interval (CI) 2.24-5.45, p < 8.97 × 10-8). Lower odds of association were found between eating nitrated dry cured meat and other psychiatric disorders. We further found that the feeding of meat preparations with added nitrate to rats resulted in hyperactivity reminiscent of human mania, alterations in brain pathways that have been implicated in human bipolar disorder, and changes in intestinal microbiota. These findings may lead to new methods for preventing mania and for developing novel therapeutic interventions.

Maternal high-fat diet results in cognitive impairment and hippocampal gene expression changes in rat offspring.

Consumption of a high-fat diet has long been known to increase risk for obesity, diabetes, and the metabolic syndrome. Further evidence strongly suggests that these same metabolic disorders are associated with an increased risk of cognitive impairment later in life. Now faced with an expanding global burden of obesity and increasing prevalence of dementia due to an aging population, understanding the effects of high-fat diet consumption on cognition is of increasingly critical importance. Further, the developmental origins of many adult onset neuropsychiatric disorders have become increasingly clear, indicating a need to investigate effects of various risk factors, including diet, across the lifespan. Here, we use a rat model to assess the effects of maternal diet during pregnancy and lactation on cognition and hippocampal gene expression of offspring. Behaviorally, adult male offspring of high-fat fed dams had impaired object recognition memory and impaired spatial memory compared to offspring of chow-fed dams. In hippocampus, we found decreased expression of Insr, Lepr, and Slc2a1 (GLUT1) among offspring of high-fat fed dams at postnatal day 21. The decreased expression of Insr and Lepr persisted at postnatal day 150. Together, these data provide additional evidence to suggest that maternal exposure to high-fat diet during pregnancy and lactation can have lasting effects on the brain, behavior, and cognition on adult offspring.

Eighteen-year-old man with autism, obsessive compulsive disorder and a SHANK2 variant presents with severe anorexia that responds to high-dose fluoxetine.

The SHANK2 gene codes for a protein involved in organising the postsynaptic density and disruptions have been associated with autism spectrum disorders (ASDs). ASDs are frequently comorbid with intellectual disability and anxiety disorders and emerging evidence suggests potentially common aetiologies. Here, we report the case of an 18-year-old man with ASD who presented with severe anorexia due to fear of food contamination, food avoidance and stereotypies attributable to underlying obsessive compulsive disorder (OCD). The patient was found to be heterozygous for c.2518C>T (p.Pro840Ser), a likely damaging coding variant in the proline rich region of SHANK2 Interestingly, the patient's disordered eating behaviour began to improve only after high-dose fluoxetine was initiated to target OCD symptoms. Overall, this case highlights the utility of molecular genetic testing in clinical psychiatry and provides an example of how genetic information can inform clinicians in the treatment of complex neuropsychiatric syndromes.

Chronic social stress induces DNA methylation changes at an evolutionary conserved intergenic region in chromosome X.

Chronic stress resulting from prolonged exposure to negative life events increases the risk of mood and anxiety disorders. Although chronic stress can change gene expression relevant for behavior, molecular regulators of this change have not been fully determined. One process that could play a role is DNA methylation, an epigenetic process whereby a methyl group is added onto nucleotides, predominantly cytosine in the CpG context, and which can be induced by chronic stress. It is unknown to what extent chronic social defeat, a model of human social stress, influences DNA methylation patterns across the genome. Our study addressed this question by using a targeted-capture approach called Methyl-Seq to investigate DNA methylation patterns of the dentate gyrus at putative regulatory regions across the mouse genome from mice exposed to 14 days of social defeat. Findings were replicated in independent cohorts by bisulfite-pyrosequencing. Two differentially methylated regions (DMRs) were identified. One DMR was located at intron 9 of Drosha, and it showed reduced methylation in stressed mice. This observation replicated in one of two independent cohorts. A second DMR was identified at an intergenic region of chromosome X, and methylation in this region was increased in stressed mice. This methylation difference replicated in two independent cohorts and in Major Depressive Disorder (MDD) postmortem brains. These results highlight a region not previously known to be differentially methylated by chronic social defeat stress and which may be involved in MDD.

Characterization of pulmonary arteriovenous malformations in ACVRL1 versus ENG mutation carriers in hereditary hemorrhagic telangiectasia.

PurposePulmonary arteriovenous malformations (pAVMs) are major contributors to morbidity and mortality in hereditary hemorrhagic telangiectasia (HHT). Mutations in ENG and ACVRL1 underlie the vast majority of clinically diagnosed cases. The aims of this study were to characterize and compare the clinical and morphologic features of pAVMs between these two genotype groups.MethodsSixty-six patients with HHT and affected family members were included. Genotype, phenotypic data, and imaging were obtained from medical records. Morphologic features of pAVMs were analyzed using computed tomography angiography. HHT symptoms, pAVM imaging characteristics, frequency of procedural intervention, and HHT severity scores were compared between ENG and ACVRL1 genotype groups.ResultsENG mutation carriers were more likely than ACVRL1 mutation carriers to have pAVMs (P < 0.001) or multiple lesions (P = 0.03), and to undergo procedural intervention (P = 0.02). Additionally, pAVMs in ENG carriers were more likely to exhibit bilateral lung involvement and growth over time, although this did not reach statistical significance. The HHT severity score was significantly higher in ENG than in ACVRL1 (P = 0.02).ConclusionThe propensity and multiplicity of ENG-associated pAVMs may contribute to the higher disease severity in this genotype, as reflected by the HHT severity score and the frequency of interventional procedures.

Genetic disruption of ankyrin-G in adult mouse forebrain causes cortical synapse alteration and behavior reminiscent of bipolar disorder.

Genome-wide association studies have implicated the ANK3 locus in bipolar disorder, a major human psychotic illness. ANK3 encodes ankyrin-G, which organizes the neuronal axon initial segment (AIS). We generated a mouse model with conditional disruption of ANK3 in pyramidal neurons of the adult forebrain (Ank-G cKO). This resulted in the expected loss of pyramidal neuron AIS voltage-gated sodium and potassium channels. There was also dramatic loss of markers of afferent GABAergic cartridge synapses, resembling the cortical microcircuitry changes in brains from psychotic patients, and suggesting disinhibition. Expression of c-fos was increased in cortical pyramidal neurons, consistent with increased neuronal activity due to disinhibition. The mice showed robust behavioral phenotypes reminiscent of aspects of human mania, ameliorated by antimania drugs lithium and valproate. Repeated social defeat stress resulted in repeated episodes of dramatic behavioral changes from hyperactivity to "depression-like" behavior, suggestive of some aspects of human bipolar disorder. Overall, we suggest that this Ank-G cKO mouse model recapitulates some of the core features of human bipolar disorder and indicates that cortical microcircuitry alterations during adulthood may be involved in pathogenesis. The model may be useful for studying disease pathophysiology and for developing experimental therapeutics.

Exendin-4 reduces food intake via the PI3K/AKT signaling pathway in the hypothalamus.

Exendin-4 (EX-4), a glucagon-like peptide-1 (GLP-1) receptor agonist, has been shown to reduce food intake and to increase proopiomelanocortin (POMC) gene expression in the hypothalamus. In this study, we examined the potential neural mechanisms by which these effects occur. Male Sprague Dawley rats were implanted with a cannula in the third ventricle of the brain through which an inhibitor of phosphatidylinositol-3 kinase (PI3K) (wortmannin) was administered, and EX-4 or vehicle was administered via intraperitoneal (IP) injection. The activity of PI3K/protein kinase B (AKT) and insulin receptor substrate-1 (IRS-1) in the hypothalamic arcuate was determined. We found that EX-4 treatment significantly decreased food intake and body weight. However, there were almost no changes in food intake and body weight when wortmannin injection (into the third ventricle) occurred prior to EX-4 IP injection. EX-4 not only increased the activity of PI3K/AKT, but it also increased IRS-1 activity. These results show that EX-4 likely suppresses food intake due to its ability to enhance insulin signaling.

Cognitive impairment and gene expression alterations in a rodent model of binge eating disorder.

Binge eating disorder (BED) is defined as recurrent, distressing over-consumption of palatable food (PF) in a short time period. Clinical studies suggest that individuals with BED may have impairments in cognitive processes, executive functioning, impulse control, and decision-making, which may play a role in sustaining binge eating behavior. These clinical reports, however, are limited and often conflicting. In this study, we used a limited access rat model of binge-like behavior in order to further explore the effects of binge eating on cognition. In binge eating prone (BEP) rats, we found novel object recognition (NOR) as well as Barnes maze reversal learning (BM-RL) deficits. Aberrant gene expression of brain derived neurotrophic factor (Bdnf) and tropomyosin receptor kinase B (TrkB) in the hippocampus (HPC)-prefrontal cortex (PFC) network was observed in BEP rats. Additionally, the NOR deficits were correlated with reductions in the expression of TrkB and insulin receptor (Ir) in the CA3 region of the hippocampus. Furthermore, up-regulation of serotonin-2C (5-HT2C) receptors in the orbitoprefrontal cortex (OFC) was associated with BM-RL deficit. Finally, in the nucleus accumbens (NAc), we found decreased dopamine receptor 2 (Drd2) expression among BEP rats. Taken together, these data suggest that binge eating vegetable shortening may induce contextual and reversal learning deficits which may be mediated, at least in part, by the altered expression of genes in the CA3-OFC-NAc neural network.