Increased hippocampal blood flow in people at clinical high risk for psychosis and effects of cannabidiol.

BACKGROUND: Hippocampal hyperperfusion has been observed in people at Clinical High Risk for Psychosis (CHR), is associated with adverse longitudinal outcomes and represents a potential treatment target for novel pharmacotherapies. Whether cannabidiol (CBD) has ameliorative effects on hippocampal blood flow (rCBF) in CHR patients remains unknown. METHODS: Using a double-blind, parallel-group design, 33 CHR patients were randomized to a single oral 600 mg dose of CBD or placebo; 19 healthy controls did not receive any drug. Hippocampal rCBF was measured using Arterial Spin Labeling. We examined differences relating to CHR status (controls v. placebo), effects of CBD in CHR (placebo v. CBD) and linear between-group relationships, such that placebo > CBD > controls or controls > CBD > placebo, using a combination of hypothesis-driven and exploratory wholebrain analyses. RESULTS: Placebo-treated patients had significantly higher hippocampal rCBF bilaterally (all pFWE<0.01) compared to healthy controls. There were no suprathreshold effects in the CBD v. placebo contrast. However, we found a significant linear relationship in the right hippocampus (pFWE = 0.035) such that rCBF was highest in the placebo group, lowest in controls and intermediate in the CBD group. Exploratory wholebrain results replicated previous findings of hyperperfusion in the hippocampus, striatum and midbrain in CHR patients, and provided novel evidence of increased rCBF in inferior-temporal and lateral-occipital regions in patients under CBD compared to placebo. CONCLUSIONS: These findings suggest that hippocampal blood flow is elevated in the CHR state and may be partially normalized by a single dose of CBD. CBD therefore merits further investigation as a potential novel treatment for this population.

The neuropharmacology of cannabinoid receptor ligands in central signaling pathways.

The endocannabinoid system is a complex neuronal system involved in a number of biological functions, like attention, anxiety, mood, memory, appetite, reward, and immune responses. It is at the centre of scientific interest, which is driven by therapeutic promise of certain cannabinoid ligands and the changing legalization of herbal cannabis in many countries. The endocannabinoid system is a modulatory system, with endocannabinoids as retrograde neurotransmitters rather than direct neurotransmitters. Neuropharmacology of cannabinoid ligands in the brain can therefore be understood in terms of their modulatory actions through other neurotransmitter systems. The CB1 receptor is chiefly responsible for effects of endocannabinoids and analogous ligands in the brain. An overview of the neuropharmacology of several cannabinoid receptor ligands, including endocannabinoids, herbal cannabis and synthetic cannabinoid receptor ligands is given in this review. Their mechanism of action at the endocannabinoid system is described, mainly in the brain. In addition, effects of cannabinoid ligands on other neurotransmitter systems will also be described, such as dopamine, serotonin, glutamate, noradrenaline, opioid, and GABA. In light of this, therapeutic potential and adverse effects of cannabinoid receptor ligands will also be discussed.

Altered relationship between cortisol response to social stress and mediotemporal function during fear processing in people at clinical high risk for psychosis: a preliminary report.

Evidence suggests that people at Clinical High Risk for Psychosis (CHR) have a blunted cortisol response to stress and altered mediotemporal activation during fear processing, which may be neuroendocrine-neuronal signatures of maladaptive threat responses. However, whether these facets are associated with each other and how this relationship is affected by cannabidiol treatment is unknown. We examined the relationship between cortisol response to social stress and mediotemporal function during fear processing in healthy people and in CHR patients. In exploratory analyses, we investigated whether treatment with cannabidiol in CHR individuals could normalise any putative alterations in cortisol-mediotemporal coupling. 33 CHR patients were randomised to 600 mg cannabidiol or placebo treatment. Healthy controls (n = 19) did not receive any drug. Mediotemporal function was assessed using a fearful face-processing functional magnetic resonance imaging paradigm. Serum cortisol and anxiety were measured immediately following the Trier Social Stress Test. The relationship between cortisol and mediotemporal blood-oxygen-level-dependent haemodynamic response was investigated using linear regression. In healthy controls, there was a significant negative relationship between cortisol and parahippocampal activation (p = 0.023), such that the higher the cortisol levels induced by social stress, the lower the parahippocampal activation (greater deactivation) during fear processing. This relationship differed significantly between the control and placebo groups (p = 0.033), but not between the placebo and cannabidiol groups (p = 0.67). Our preliminary findings suggest that the parahippocampal response to fear processing may be associated with the neuroendocrine (cortisol) response to experimentally induced social stress, and that this relationship may be altered in patients at clinical high risk for psychosis.

Integrated metastate functional connectivity networks predict change in symptom severity in clinical high risk for psychosis.

The ability to identify biomarkers of psychosis risk is essential in defining effective preventive measures to potentially circumvent the transition to psychosis. Using samples of people at clinical high risk for psychosis (CHR) and Healthy controls (HC) who were administered a task fMRI paradigm, we used a framework for labelling time windows of fMRI scans as 'integrated' FC networks to provide a granular representation of functional connectivity (FC). Periods of integration were defined using the 'cartographic profile' of time windows and k-means clustering, and sub-network discovery was carried out using Network Based Statistics (NBS). There were no network differences between CHR and HC groups. Within the CHR group, using integrated FC networks, we identified a sub-network negatively associated with longitudinal changes in the severity of psychotic symptoms. This sub-network comprised brain areas implicated in bottom-up sensory processing and in integration with motor control, suggesting it may be related to the demands of the fMRI task. These data suggest that extracting integrated FC networks may be useful in the investigation of biomarkers of psychosis risk.

Brain Microdialysate Monoamines in Relation to Circadian Rhythms, Sleep, and Sleep Deprivation - a Systematic Review, Network Meta-analysis, and New Primary Data.

Disruption of the monoaminergic system, e.g. by sleep deprivation (SD), seems to promote certain diseases. Assessment of monoamine levels over the circadian cycle, during different sleep stages and during SD is instrumental to understand the molecular dynamics during and after SD. To provide a complete overview of all available evidence, we performed a systematic review. A comprehensive search was performed for microdialysis and certain monoamines (dopamine, serotonin, noradrenaline, adrenaline), certain monoamine metabolites (3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA)) and a precursor (5-hydroxytryptophan (5-HTP)) in PubMed and EMBASE. After screening of the search results by two independent reviewers, 94 publications were included. All results were tabulated and described qualitatively. Network-meta analyses (NMAs) were performed to compare noradrenaline and serotonin concentrations between sleep stages. We further present experimental monoamine data from the medial prefrontal cortical (mPFC). Monoamine levels varied with brain region and circadian cycle. During sleep, monoamine levels generally decreased compared to wake. These qualitative observations were supported by the NMAs: noradrenaline and serotonin levels decreased from wakefulness to slow wave sleep and decreased further during Rapid Eye Movement sleep. In contrast, monoamine levels generally increased during SD, and sometimes remained high even during subsequent recovery. Decreases during or after SD were only reported for serotonin. In our experiment, SD did not affect any of the mPFC monoamine levels. Concluding, monoamine levels vary over the light-dark cycle and between sleep stages. SD modifies the patterns, with effects sometimes lasting beyond the SD period.

Sleep and Microdialysis: An Experiment and a Systematic Review of Histamine and Several Amino Acids.

Sleep seems essential to proper functioning of the prefrontal cortex (PFC). The role of different neurotransmitters has been studied, mainly the catecholamines and serotonin. Less attention has been paid to the amino acid transmitters and histamine. Here, we focus on the activity of these molecules in the PFC during sleep and sleep deprivation (SD). We determined extracellular concentrations of histamine and 8 amino acids in the medial PFC before, during and after SD. Additionally, we systematically reviewed the literature on studies reporting microdialysis measurements relating to sleep throughout the brain. In our experiment, median concentrations of glutamate were higher during SD than during baseline (p = 0.013) and higher during the dark-active than during the resting phase (p = 0.003). Glutamine was higher during post-SD recovery than during baseline (p = 0.010). For other compounds, no differences were observed between light and dark circadian phase, and between sleep deprivation, recovery and baseline. We retrieved 13 papers reporting on one or more of the molecules of interest during naturally occurring sleep, 2 during sleep deprivation and 2 during both. Only two studies targeted PFC. Histamine was low during sleep, but high during sleep deprivation and wakefulness, irrespective of brain area. Glu (k = 11) and GABA (k = 8) concentrations in different brain areas were reported to peak during sleep or wakefulness or to lack state-dependency. Aspartate, glycine, asparagine and taurine were less often studied (1-2 times), but peaked exclusively during sleep. Sleep deprivation increased glutamate and GABA exclusively in the cortex. Further studies are needed for drawing solid conclusions.

Human Striatal Response to Reward Anticipation Linked to Hippocampal Glutamate Levels.

Background: Dysfunctional reward processing is associated with a number of psychiatric disorders, such as addiction and schizophrenia. It is thought that reward is regulated mainly by dopamine transmission in the ventral striatum. Contemporary animal models suggest that striatal dopamine concentrations and associated behaviors are related to glutamatergic functioning in the ventral hippocampus. However, in humans the association between reward-related ventral striatal response and hippocampal glutamate levels is unclear. Methods: Nineteen healthy participants were studied using proton magnetic resonance spectroscopy to measure hippocampal glutamate levels, and functional magnetic resonance imaging to assess striatal activation and functional connectivity during performance of a monetary incentive delay task. Results: We found that ventral striatal activation related to reward processing was correlated with hippocampal glutamate levels. In addition, context-dependent functional coupling was demonstrated between the ventral striatum and both the lingual gyrus and hippocampus during reward anticipation. Elevated hippocampal glutamate levels were inversely related to context-dependent functional connectivity between the ventral striatum and the anterior hippocampus while anticipating reward. Conclusions: These findings indicate that human striatal responses to reward are influenced by hippocampal glutamate levels. This may be relevant for psychiatric disorders associated with abnormal reward processing such as addiction and schizophrenia.

The acute effects of cannabis on human executive function.

Cannabis remains the most frequently used illicit drug worldwide. It produces a broad range of acute effects, such as euphoria, increased heart rate and perceptual alterations. Over the last few decades, a substantial number of experiments have been conducted to provide insight into the acute effects of cannabis on cognition. Here, we systematically review studies that investigated the impact of administration of cannabis or [INCREMENT]-tetrahydrocannabinol, the main psychoactive constituent of cannabis, on human executive function, in particular, on the three principal domains of inhibition, working memory and reasoning/association. Our findings suggest that cannabis use results in acute impairment of inhibition, with the strongest effects after pulmonary administration of higher doses of [INCREMENT]-tetrahydrocannabinol. Results from neuroimaging studies indicate that these effects are predominantly modulated through neural processes in the inferior frontal gyrus. Working memory and reasoning/association are less clearly affected by cannabis administration, possibly because of compensational neural mechanisms to overcome the effects of cannabis intoxication on performance accuracy. Factors that may account for the variation in results are the extent to which a paradigm involves attentional processes, differences between studies in administration methods and variation in the patients' history of cannabis use.

Intracerebral Adenosine During Sleep Deprivation: A Meta-Analysis and New Experimental Data.

The neuroregulator adenosine is involved in sleep-wake control. Basal forebrain (BF) adenosine levels increase during sleep deprivation. Only a few studies have addressed the effect of sleep deprivation on extracellular adenosine concentrations in other brain regions. In this paper, we describe a microdialysis experiment as well as a meta-analysis of published data. The 64 h microdialysis experiment determined the extracellular adenosine and adenosine monophosphate (AMP) concentrations in the medial prefrontal cortex of rats before, during and after 12 h of sleep deprivation by forced locomotion. The meta-analysis comprised published sleep deprivation animal experiments measuring adenosine by means of microdialysis. In the animal experiment, the overall median adenosine concentration was 0.36 nM and ranged from 0.004 nM to 27 nM. No significant differences were observed between the five conditions: 12 h of wash-out, baseline light phase, baseline dark phase, 12 h of sleep deprivation and 12 h of subsequent recovery. The overall median AMP concentration was 0.10 nM and ranged from 0.001 nM to 7.56 nM. Median AMP concentration increased during sleep deprivation (T = 47; p = 0.047) but normalised during subsequent recovery. The meta-analysis indicates that BF dialysate adenosine concentrations increase with 74.7% (95% CI: 54.1-95.3%) over baseline during sleep deprivation. Cortex dialysate adenosine concentrations during sleep deprivation were so far only reported by 2 publications. The increase in adenosine during sleep deprivation might be specific to the BF. At this stage, the evidence for adenosine levels in other brain regions is based on single experiments and insufficient for generalised conclusions. Further experiments are currently still warranted.

Microsatellite instable vs stable colon carcinomas: analysis of tumour heterogeneity, inflammation and angiogenesis.

BACKGROUND: Microsatellite instability (MSI) accounts for 15% of all colorectal tumours. Several specific clinicopathologicals (e.g., preference for the proximal colon over the distal colon, improved prognosis and altered response to chemotherapeutics) are described for this subset of tumours. This study aimed to analyse morphological, inflammatory and angiogenic features of MSI vs microsatellite stable (MSS) tumours. METHODS: Twenty-seven MSS and 29 MSI, TNM stage matched, colorectal tumours were selected from the archive of the Department of Pathology, UZ Leuven. Morphology was analysed on haematoxylin-eosin sections. Immunohistochemistry for CD3, CD4, CD8, CD20 and CD68 was used to map tumour infiltration in both a digital and traditional microscope-based manner for all distinct morphological components of the tumour. CD31 immunostains were performed to assess angiogenesis. RESULTS: Morphological tumour heterogeneity was a marked feature of MSI tumours, occurring in 53% of the cases as compared with 11% of the MSS tumours (P<0.001). Digital immune quantification showed an increased number of tumour-infiltrating cytotoxic T-lymphocytes (CD8+) in MSI compared with MSS tumours for both the tumour (P=0.02) and peritumoural area (P=0.03). Traditional microscope-based quantification confirmed these results (P<0.001 for both) and, in addition, revealed large numbers of CD68+ macrophages in the peritumoural area of MSI cancers (P=0.001). Moreover, traditional microscope-based analysis was able to distinguish between lymphocytes directly infiltrating the tumoural glands (intra-epithelial) and those infiltrating only the neoplastic stroma around the glands (intratumoural). Quantification showed high numbers of intra-epithelial CD3+, CD4+, CD8+, CD20+ and CD68+ cells in MSI compared with MSS cancers (P<0.001, P=0.01, P<0.001, P<0.001 and P=0.006, respectively). Higher microvessel density (MVD) was observed in MSI tumours compared with their MSS counterpart. CONCLUSIONS: Mixed morphology, reflecting tumour heterogeneity, is an important feature of MSI tumours and may have both diagnostic and therapeutic impact. The inflammatory reaction also presented with significant differences in MSI vs MSS colorectal tumours. MSI cancers showed mainly infiltration by cytotoxic T-cells in both the tumour and the close border around the tumour, as well as increased intra-epithelial infiltration in contrast to MSS tumours. The type of immune cell and the compartment it resides in (intratumoural or intra-epithelial) depend both on MSI status and morphology. Finally, MSI tumours showed a higher angiogenic capacity represented by an increased MVD, hinting for possible therapeutic consequences.

Antisense-mediated therapeutic pseudoexon skipping in TMEM165-CDG.

Deficiencies in glycosyltransferases, glycosidases or nucleotide-sugar transporters involved in protein glycosylation lead to congenital disorders of glycosylation (CDG), a group of genetic diseases mostly showing multisystem phenotype. Despite recent advances in the biochemical and molecular knowledge of these diseases, no effective therapy exists for most. Efforts are now being directed toward therapies based on identifying new targets, which would allow to treat specific patients in a personalized way. This work presents proof-of concept for the antisense RNA rescue of the Golgi-resident protein TMEM165, a gene involved in a new type of CDG with a characteristic skeletal phenotype. Using a functional in vitro splicing assay based on minigenes, it was found that the deep intronic change c.792+182G>A is responsible for the insertion of an aberrant exon, corresponding to an intronic sequence. Antisense morpholino oligonucleotide therapy targeted toward TMEM165 mRNA recovered normal protein levels in the Golgi apparatus of patient-derived fibroblasts. This work expands the application of antisense oligonucleotide-mediated pseudoexon skipping to the treatment of a Golgi-resident protein, and opens up a promising treatment option for this specific TMEM165-CDG.

Mutations in PMM2, a phosphomannomutase gene on chromosome 16p13, in carbohydrate-deficient glycoprotein type I syndrome (Jaeken syndrome).

Carbohydrate-deficient glycoprotein syndrome type 1 (CDG1 or Jaeken syndrome) is the prototype of a class of genetic multisystem disorders characterized by defective glycosylation of glycoconjugates. It is mostly a severe disorder which presents neonatally. There is a severe encephalopathy with axial hypotonia, abnormal eye movements and pronounced psychomotor retardation, as well as a peripheral neuropathy, cerebellar hypoplasia and retinitis pigmentosa. The patients show a peculiar distribution of subcutaneous fat, nipple retraction and hypogonadism. There is a 20% lethality in the first years of life due to severe infections, liver insufficiency or cardiomyopathy. CDG1 shows an autosomal recessive mode of inheritance and has been mapped to chromosome 16p. Most patients show a deficiency of phosphomannomutase (PMM)8, an enzyme necessary for the synthesis of GDP-mannose. We have cloned the PMM1 gene, which is on chromosome 22q13 (ref.9). We now report the identification of a second human PMM gene, PMM2, which is located on 16p13 and which encodes a protein with 66% identity to PMM1. We found eleven different missense mutations in PMM2 in 16 CDG1 patients from different geographical origins and with a documented phosphomannomutase deficiency. Our results give conclusive support to the biochemical finding that the phosphomannomutase deficiency is the basis for CDG1.

SOX10 mutations in patients with Waardenburg-Hirschsprung disease.

Waardenburg syndrome (WS; deafness with pigmentary abnormalities) and Hirschsprung's disease (HSCR; aganglionic megacolon) are congenital disorders caused by defective function of the embryonic neural crest. WS and HSCR are associated in patients with Waardenburg-Shah syndrome (WS4), whose symptoms are reminiscent of the white coat-spotting and aganglionic megacolon displayed by the mouse mutants Dom (Dominant megacolon), piebald-lethal (sl) and lethal spotting (ls). The sl and ls phenotypes are caused by mutations in the genes encoding the Endothelin-B receptor (Ednrb) and Endothelin 3 (Edn3), respectively. The identification of Sox10 as the gene mutated in Dom mice (B.H. et al., manuscript submitted) prompted us to analyse the role of its human homologue SOX10 in neural crest defects. Here we show that patients from four families with WS4 have mutations in SOX10, whereas no mutation could be detected in patients with HSCR alone. These mutations are likely to result in haploinsufficiency of the SOX10 product. Our findings further define the locus heterogeneity of Waardenburg-Hirschsprung syndromes, and point to an essential role of SOX10 in the development of two neural crest-derived human cell lineages.

Acute effects of Δ9-tetrahydrocannabinol (THC) on resting state connectivity networks and impact of COMT genotype: A multi-site pharmacological fMRI study.

BACKGROUND: Cannabis produces various acute psychotropic effects, with marked individual differences. Cannabis use is a risk factor for developing psychotic disorders. The main component responsible for these effects is Δ9-tetrahydrocannabinol (THC). Here we investigated the neural basis of acute THC effects and its modulation by catechol-methyl-transferase (COMT) Val158Met genotype. METHODS: Resting state functional MRI data of healthy occasional cannabis users were combined and re-analyzed from three double-blind, placebo-controlled, within-subject pharmacological functional magnetic resonance imaging studies (total N=87). Functional connectivity after placebo and THC was compared in three functional networks (salience, executive and default mode network) and a network implicated in psychosis (the hippocampus-midbrain-striatum network). COMT genotype modulation of subjective effects and connectivity was examined. RESULTS: THC reduced connectivity in the salience network, specifically from the right insula to both the left insula and anterior cingulate cortex. We found a trend towards decreased connectivity in the hippocampus-midbrain-striatum network after THC. COMT genotype modulated subjective effects of THC, with strongest dysphoric reactions in Met/Met individuals. In addition, reduced connectivity after THC was demonstrated in the hippocampus-midbrain-striatum network of Met/Met individuals only. CONCLUSIONS: In this large multisite study we found that THC robustly decreases connectivity in the salience network, involved in processing awareness and salient information. Connectivity changes in the hippocampus-midbrain-striatum network may reflect the acute psychotic-like effects of THC. COMT genotype modulation of THC's impact on subjective effects and functional connectivity provides further evidence for involvement of prefrontal dopamine levels in the acute effects of cannabis.

Therapeutic effect of psilocybin in addiction: A systematic review.

Background: Psychedelic-assisted therapy [e.g., with lysergic acid diethylamide (LSD)] has shown promising results as treatment for substance use disorders (SUDs). Previous systematic reviews assessing the efficacy of psilocybin in SUDs only included clinical trials conducted in the last 25 years, but they may have missed clinical trials assessing the efficacy of psilocybin that were conducted before the 1980s, given much research has been done with psychedelics in the mid-20th century. In this systematic review, we specifically assessed the efficacy of psilocybin in patients with a SUD or non-substance-related disorder with no publication date restrictions in our search strategy. Methods: A systematic literature search was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines from the earliest published manuscript up to September 2, 2022, in seven electronic databases, including clinical trials in patients with a SUD or non-substance-related disorder evaluating the efficacy of psilocybin. Results: A total of four studies (six articles, of which two articles were long-term follow-up results from the same trial) were included in this systematic review. Psilocybin-assisted therapy was administered to n = 151 patients in a dose ranging from 6 to 40 mg. Three studies focused on alcohol use disorder, and one study on tobacco use disorder. In a pilot study (n = 10), the percentage of heavy drinking days decreased significantly between baseline and weeks 5-12 (mean difference of 26.0, 95% CI = 8.7-43.2, p = 0.008). In another single-arm study (n = 31), 32% (10/31) became completely abstinent from alcohol (mean duration of follow-up 6 years). In a double-blind, placebo-controlled randomized controlled trial (RCT, n = 95), the percentage of heavy drinking days during the 32-week double-blind period was significantly lower for psilocybin compared to placebo (mean difference of 13.9, 95% CI = 3.0-24.7, p = 0.01). In a pilot study (n = 15), the 7-day point prevalence of smoking abstinence at 26 weeks was 80% (12/15), and at 52 weeks 67% (10/15). Conclusion: Only one RCT and three small clinical trials were identified assessing the efficacy of psilocybin combined with some form of psychotherapy in patients with alcohol and tobacco use disorder. All four clinical trials indicated a beneficial effect of psilocybin-assisted therapy on SUD symptoms. Larger RCTs in patients with SUDs need to evaluate whether psilocybin-assisted therapy is effective in patients with SUD.

Hippocampal Glutamate, Resting Perfusion and the Effects of Cannabidiol in Psychosis Risk.

Background: Preclinical and human data suggest that psychosis onset involves hippocampal glutamatergic dysfunction, driving hyperactivity and hyperperfusion in a hippocampal-midbrain-striatal circuit. Whether glutamatergic dysfunction is related to cerebral perfusion in patients at clinical high risk (CHR) for psychosis, and whether cannabidiol (CBD) has ameliorative effects on glutamate or its relationship with perfusion remains unknown. Methods: Using a double-blind, parallel-group design, 33 CHR patients were randomized to a single 600 mg dose of CBD or placebo; 19 healthy controls did not receive any drug. Proton magnetic resonance spectroscopy was used to measure glutamate concentrations in left hippocampus. We examined differences relating to CHR status (controls vs placebo), effects of CBD (placebo vs CBD), and linear between-group effects, such that placebo>CBD>controls or controls>CBD>placebo. We also examined group × glutamate × cerebral perfusion (measured using Arterial Spin Labeling) interactions. Results: Compared to controls, CHR-placebo patients had significantly lower hippocampal glutamate (P =.015) and a significant linear relationship was observed across groups, such that glutamate was highest in controls, lowest in CHR-placebo, and intermediate in CHR-CBD (P =.031). Moreover, there was a significant interaction between group (controls vs CHR-placebo), hippocampal glutamate, and perfusion in the putamen and insula (P FWE =.012), with a strong positive correlation in CHR-placebo vs a negative correlation in controls. Conclusions: Our findings suggest that hippocampal glutamate is lower in CHR patients and may be partially normalized by a single dose of CBD. Furthermore, we provide the first in vivo evidence of an abnormal relationship between hippocampal glutamate and perfusion in the striatum and insula in CHR.

The impact of cannabidiol treatment on resting state functional connectivity, prefrontal metabolite levels and reward processing in recent-onset patients with a psychotic disorder.

The first clinical trials with cannabidiol (CBD) as treatment for psychotic disorders have shown its potential as an effective and well-tolerated antipsychotic agent. However, the neurobiological mechanisms underlying the antipsychotic profile of CBD are currently unclear. Here we investigated the impact of 28-day adjunctive CBD or placebo treatment (600 mg daily) on brain function and metabolism in 31 stable recent-onset psychosis patients (<5 years after diagnosis). Before and after treatment, patients underwent a Magnetic Resonance Imaging (MRI) session including resting state functional MRI, proton Magnetic Resonance Spectroscopy (1H-MRS) and functional MRI during reward processing. Symptomatology and cognitive functioning were also assessed. CBD treatment significantly changed functional connectivity in the default mode network (DMN; time × treatment interaction p = 0.037), with increased connectivity in the CBD (from 0.59 ± 0.39 to 0.80 ± 0.32) and reduced connectivity in the placebo group (from 0.77 ± 0.37 to 0.62 ± 0.33). Although there were no significant treatment effects on prefrontal metabolite concentrations, we showed that decreased positive symptom severity over time was associated with both diminishing glutamate (p = 0.029) and N-acetyl-aspartate (NAA; neuronal integrity marker) levels (p = 0.019) in the CBD, but not the placebo group. CBD treatment did not have an impact on brain activity patterns during reward anticipation and receipt or functional connectivity in executive and salience networks. Our results show that adjunctive CBD treatment of recent-onset psychosis patients induced changes in DMN functional connectivity, but not prefrontal metabolite concentrations or brain activity during reward processing. These findings suggest that DMN connectivity alteration may be involved in the therapeutic effects of CBD.

Clinical and diagnostic approach in unsolved CDG patients with a type 2 transferrin pattern.

Dysmorphic features, multisystem disease, and central nervous system involvement are common symptoms in congenital disorders of glycosylation, including several recently discovered Golgi-related glycosylation defects. In search for discriminative features, we assessed eleven children suspected with a Golgi-related inborn error of glycosylation. We evaluated all genetically unsolved patients, diagnosed with a type 2 transferrin isofocusing pattern in the period of 1999-2009. By combining biochemical results with characteristic clinical symptoms, we used a diagnostic flow chart to approach the underlying defect in patients with congenital disorders of glycosylation-IIx. According to specific symptoms and laboratory results, we initiated additional, targeted biochemical and genetic studies. We found a distinctive spectrum of congenital disorders of glycosylation type 2-associated anomalies including sudden hearing loss, brain malformations, wrinkled skin, and epilepsy in combination with skeletal dysplasia, dilated cardiomyopathy, sudden cardiac arrest, abnormal copper and iron metabolism, and endocrine abnormalities in our patients. One patient with severe cortical malformations and mild skin abnormalities was diagnosed with a known genetic syndrome, due to an ATP6V0A2 defect. Here, we present unique congenital disorders of glycosylation type 2-associated anomalies, including both ATPase-related and unrelated cutis laxa and sensorineural hearing loss, a recently recognized symptom of congenital disorders of glycosylation. Based on our findings, we recommend clinicians to consider congenital disorders of glycosylation in patients with cardiac rhythm disorders, spondylodysplasia and biochemical abnormalities of the copper and iron metabolism even in absence of intellectual disability.

Effects of Δ9-tetrahydrocannabinol administration on human encoding and recall memory function: a pharmacological FMRI study.

Deficits in memory function are an incapacitating aspect of various psychiatric and neurological disorders. Animal studies have recently provided strong evidence for involvement of the endocannabinoid (eCB) system in memory function. Neuropsychological studies in humans have shown less convincing evidence but suggest that administration of cannabinoid substances affects encoding rather than recall of information. In this study, we examined the effects of perturbation of the eCB system on memory function during both encoding and recall. We performed a pharmacological MRI study with a placebo-controlled, crossover design, investigating the effects of Δ9-tetrahydrocannabinol (THC) inhalation on associative memory-related brain function in 13 healthy volunteers. Performance and brain activation during associative memory were assessed using a pictorial memory task, consisting of separate encoding and recall conditions. Administration of THC caused reductions in activity during encoding in the right insula, the right inferior frontal gyrus, and the left middle occipital gyrus and a network-wide increase in activity during recall, which was most prominent in bilateral cuneus and precuneus. THC administration did not affect task performance, but while during placebo recall activity significantly explained variance in performance, this effect disappeared after THC. These findings suggest eCB involvement in encoding of pictorial information. Increased precuneus activity could reflect impaired recall function, but the absence of THC effects on task performance suggests a compensatory mechanism. These results further emphasize the eCB system as a potential novel target for treatment of memory disorders and a promising target for development of new therapies to reduce memory deficits in humans.

Deep brain stimulation of the accumbens increases dopamine, serotonin, and noradrenaline in the prefrontal cortex.

Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is effective in treatment-refractory obsessive-compulsive disorder and major depressive disorder. However, little is known about the neurobiological mechanisms underlying the rapid and effective changes of DBS. One of the hypotheses is that DBS modulates activity of monoamine neurotransmitters. In this study, we evaluated the effects of DBS in the NAc core on the extracellular concentration of monoaminergic neurotransmitters in the medial (mPFC) and orbital prefrontal cortex (OFC). Freely moving rats were bilaterally stimulated in the NAc core for 2 h while dopamine, serotonin, and noradrenaline were measured using in vivo microdialysis in the mPFC and the OFC. We report rapid increases in the release of dopamine and serotonin to a maximum of 177% and 127% in the mPFC and an increase up to 171% and 166% for dopamine and noradrenaline in the OFC after onset of stimulation in the NAc core. These results provide further evidence for the distal effects of DBS and corroborate previous clinical and pre-clinical findings of altered neuronal activity in prefrontal areas.