Subacute changes in brain functional network connectivity after nocturnal sodium oxybate intake are associated with anterior cingulate GABA.

Sodium oxybate (γ-hydroxybutyrate, GHB) is an endogenous GHB/GABAB receptor agonist, clinically used to promote slow-wave sleep and reduce next-day sleepiness in disorders such as narcolepsy and fibromyalgia. The neurobiological signature of these unique therapeutic effects remains elusive. Promising current neuropsychopharmacological approaches to understand the neural underpinnings of specific drug effects address cerebral resting-state functional connectivity (rsFC) patterns and neurometabolic alterations. Hence, we performed a placebo-controlled, double-blind, randomized, cross-over pharmacological magnetic resonance imaging study with a nocturnal administration of GHB, combined with magnetic resonance spectroscopy of GABA and glutamate in the anterior cingulate cortex (ACC). In sum, 16 healthy male volunteers received 50 mg/kg GHB p.o. or placebo at 02:30 a.m. to maximize deep sleep enhancement and multi-modal brain imaging was performed at 09:00 a.m. of the following morning. Independent component analysis of whole-brain rsFC revealed a significant increase of rsFC between the salience network (SN) and the right central executive network (rCEN) after GHB intake compared with placebo. This SN-rCEN coupling was significantly associated with changes in GABA levels in the ACC (pall < 0.05). The observed neural pattern is compatible with a functional switch to a more extrinsic brain state, which may serve as a neurobiological signature of the wake-promoting effects of GHB.

Experiences of harm and mental ill-health among gay, bisexual and other men-who-have-sex-with-men who use methamphetamine or GHB/GBL in different combinations: findings from the COMeT study in Taiwan.

INTRODUCTION: Polydrug use in the context of chemsex is commonplace among gay, bisexual, and other men-who-have-sex-with-men (GBMSM). This study aimed to examine the differences in experiences of physical, social, and psychological harms, as well as mental ill-health among GBMSM who use different combinations of methamphetamine and gamma-hydroxybutyric acid/gamma-butyrolactone (GHB/GBL) during chemsex. METHOD: Adult GBMSM participants who had experience of chemsex in the past 12 months participated in a cross-sectional online survey in Taiwan and self-reported their sociodemographic background, sexual behaviours, mental health, and experiences of harm following a chemsex session. We used univariable and multivariable logistic regression to assess the different experiences of harm and mental ill-health among GBMSM who engaged in chemsex without using methamphetamine, used methamphetamine but not GHB/GBL, and who used both drugs. RESULTS: Out of 510 participants who completed all items included in the analysis, 24.1% engaged in chemsex without using methamphetamine, 36.9% used methamphetamine but not GHB/GBL, and 39.0% used both drugs. Eighty five percent of men who used both methamphetamine and GHB/GBL reported at least one kind of social harm after a chemsex session, such as missing dates or appointments, or appearing "high" at work, followed by used methamphetamine but not GHB/GBL (69.7%) and those without using methamphetamine (37.4%). After controlling for polydrug and frequency of drug use in the multivariable logistic regression, those who used methamphetamine but not GHB/GBL and those who used both drugs were more likely to report experiencing physical and psychological harms compared to those who did not use methamphetamine (p < 0.003). CONCLUSION: GBMSM who used both methamphetamine and GHB/GBL in a chemsex context were more likely to report experience of harms than those who only used a single chemsex drug or engaged in chemsex without methamphetamine or GHB/GBL. Harm reduction should focus on both preventing HIV and STI transmission and on minimising psychosocial harm to GBMSM, with varying impacts depending on drug use.

Nocturnal sodium oxybate increases the anterior cingulate cortex magnetic resonance glutamate signal upon awakening.

Clinical guidelines recommend sodium oxybate (SXB; the sodium salt of γ-hydroxybutyrate) for the treatment of disturbed sleep and excessive daytime sleepiness in narcolepsy, yet the underlying mode of action is elusive. In a randomised controlled trial in 20 healthy volunteers, we aimed at establishing neurochemical changes in the anterior cingulate cortex (ACC) following SXB-enhanced sleep. The ACC is a core neural hub regulating vigilance in humans. At 2:30 a.m., we administered in a double-blind cross-over manner an oral dose of 50 mg/kg SXB or placebo, to enhance electroencephalography-defined sleep intensity in the second half of nocturnal sleep (11:00 p.m. to 7:00 a.m.). Upon scheduled awakening, we assessed subjective sleepiness, tiredness and mood and measured two-dimensional, J-resolved, point-resolved magnetic resonance spectroscopy (PRESS) localisation at 3-Tesla field strength. Following brain scanning, we used validated tools to quantify psychomotor vigilance test (PVT) performance and executive functioning. We analysed the data with independent t tests, false discovery rate (FDR) corrected for multiple comparisons. The morning glutamate signal (at 8:30 a.m.) in the ACC was specifically increased after SXB-enhanced sleep in all participants in whom good-quality spectroscopy data were available (n = 16; pFDR < 0.002). Further, global vigilance (10th-90th inter-percentile range on the PVT) was improved (pFDR < 0.04) and median PVT response time was shorter (pFDR < 0.04) compared to placebo. The data indicate that elevated glutamate in the ACC could provide a neurochemical mechanism underlying SXB's pro-vigilant efficacy in disorders of hypersomnolence.

[Withdrawal syndrome following chronic use of gamma-hydroxybutyric acid (GHB)]. / Syndrome de sevrage lors d'une consommation chronique d'acide gamma-hydroxybutyrique (GHB).

Chronic use of gamma-hydroxybutyric acid (GHB) and its precursors can rapidly lead to physical dependence with the emergence of a withdrawal syndrome. This complication is similar to the one linked to alcohol or benzodiazepines. The onset of symptoms and specially neuro-psychiatric symptoms is, however, more rapid in the case of the GHB and precursors. There is currently no consensus on the therapeutic management of GHB withdrawal syndrome. High-dose benzodiazepines are the most commonly used treatment. The use of GHB by titration and tapering could show fewer side effects and withdrawal symptoms. It appears necessary to reflect on and pursue research on the use of GHB and its precursors, which remains poorly understood, on the management of withdrawal syndrome due to the lack of protocol and on its probably underestimated impact on public health.

La consommation chronique d'acide gamma-hydroxybutyrique (GHB) et de ses précurseurs peut rapidement entraîner une dépendance physique avec l'émergence d'un syndrome de sevrage à l'arrêt des consommations. Ce syndrome de sevrage présente des similitudes avec celui lié à l'alcool ou aux benzodiazépines. On retrouvera, cependant, une apparition et une évolution plus brutales ainsi que l'émergence, plus précoce, de symptômes neuropsychiatriques. Il n'y a actuellement pas de consensus concernant la prise en charge thérapeutique de ce syndrome de sevrage. Dès lors, le recours aux benzodiazépines à hautes doses constitue le traitement le plus régulièrement utilisé. L'utilisation de GHB médical, titré et avec une posologie progressivement diminuée, pourrait démontrer moins d'effets secondaires et de symptômes de sevrage. Il apparaît nécessaire de réfléchir et de poursuivre les recherches sur la consommation du GHB et ses précurseurs, qui reste largement méconnue, ainsi que sur la prise en charge du sevrage, au vu de l'absence de protocole et de son impact en santé publique, probablement sous-estimé.

Learning and memory impairment induced by 1,4-butanediol is regulated by ERK1/2-CREB-BDNF signaling pathways in PC12 cells.

1,4-butanediol (1,4-BD) is a known γ-hydroxybutyric acid (GHB) precursor which affects the nervous system after ingestion, leading to uncontrolled behavioral consequences. In the present study, we investigated whether 1,4-BD induces oxidative stress and inflammation in PC12 cells and evaluated the toxic effects of 1,4-BD associates with learning and memory. CCK-8 results revealed a dose-effect relationship between the cell viability of PC12 cells and 1,4-BD when the duration of action was 2 h or 4 h. Assay kits results showed that 1,4-BD decreased the levels of Glutathione (GSH), Glutathione peroxidase (GSH-px), Superoxide dismutase (SOD), Acetylcholine (Ach) and increased the levels of Malondialdehyde (MDA), Nitric oxide (NO) and Acetylcholinesterase (AchE). Elisa kits results indicated that 1,4-BD decreased the levels of synaptophysin I (SYN-1), Postsynaptic density protein-95 (PSD-95), Growth associated protein-43 (GAP-43) and increased the levels of Tumor necrosis factor alpha (TNF-α) and Interleukin- 6 (IL-6). RT-PCR results showed that the mRNA levels of PSD-95, SYN-1 and GAP-43 were significantly decreased. The expression of phosphorylation extracellular signal-regulated protein kinase 1/2 (p-ERK1/2), phosphorylation cAMP response element binding protein (p-CREB) and brain-derived neurotrophic factor (BDNF) proteins were significantly decreased in PC12 cells by protein blotting. Overall, these results suggest that 1,4-BD may affect synaptic plasticity via the ERK1/2-CREB-BDNF pathway, leading to Ach release reduction and ultimately to learning and memory impairment. Furthermore, oxidative stress and inflammation induced by 1,4-BD may also result in learning and memory deficits. These findings will enrich the toxicity data of 1.4-BD associated with learning and memory impairment.

Understanding the Molecular Mechanisms of Succinic Semialdehyde Dehydrogenase Deficiency (SSADHD): Towards the Development of SSADH-Targeted Medicine.

Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a rare genetic disorder caused by inefficient metabolic breakdown of the major inhibitory neurotransmitter, γ-aminobutyric acid (GABA). Pathologic brain accumulation of GABA and γ-hydroxybutyrate (GHB), a neuroactive by-product of GABA catabolism, leads to a multitude of molecular abnormalities beginning in early life, culminating in multifaceted clinical presentations including delayed psychomotor development, intellectual disability, hypotonia, and ataxia. Paradoxically, over half of patients with SSADHD also develop epilepsy and face a significant risk of sudden unexpected death in epilepsy (SUDEP). Here, we review some of the relevant molecular mechanisms through which impaired synaptic inhibition, astrocytic malfunctions and myelin defects might contribute to the complex SSADHD phenotype. We also discuss the gaps in knowledge that need to be addressed for the implementation of successful gene and enzyme replacement SSADHD therapies. We conclude with a description of a novel SSADHD mouse model that enables 'on-demand' SSADH restoration, allowing proof-of-concept studies to fine-tune SSADH restoration in preparation for eventual human trials.

Detection of Exogenous γ-Hydroxybutyric Acid in Rat Blood Exosomes.

OBJECTIVES: To find a method to distinguish exogenous gamma-hydroxybutyrate (GHB) from endogenous GHB by establishing ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) based on exosome for quantitative detection of GHB in the rat blood. METHODS: Adult male SD rats were divided into 1 h, 5 h, 10 h administration group and control group. After 1 h, 5 h and 10 h of single precursor of GHB gamma-butyrolactone (GBL) intraperitoneal injection in administration groups, 5 mL blood was collected from the abdominal aorta. Meanwhile, the control group was given a same dose of normal saline, and 5 mL blood was collected at 1 h. Among the 5 mL blood, 0.5 mL was directly detected by HPLC-MS after pretreatment, and exosomes were extracted from the remaining blood by differential centrifugation and detected. RESULTS: The concentration of GHB in the control group was (87.36±33.48) ng/mL, and the concentration with administration at 1 h, 5 h and 10 h was (110 400.00±1 766.35) ng/mL, (1 479.00±687.01) ng/mL and (133.60±12.17) ng/mL, respectively. The results of exosome detection showed that no peak GHB signal was detected in the control group and the 10 h administration group, and the concentrations of GHB at 1 h and 5 h administration groups were (91.47±33.44) ng/mL and (49.43±7.05) ng/mL, respectively. CONCLUSIONS: GHB was detected in blood exosome by UPLC-MS, which indicated that exogenous GHB could be detected in plasma exosomes, while endogenous GHB could not be detected, suggesting that this method may be used as a basis to determine whether there is exogenous drug intake.

γ-Hydroxybutyrate does not mediate glucose inhibition of glucagon secretion.

Hypersecretion of glucagon from pancreatic α-cells strongly contributes to diabetic hyperglycemia. Moreover, failure of α-cells to increase glucagon secretion in response to falling blood glucose concentrations compromises the defense against hypoglycemia, a common complication in diabetes therapy. However, the mechanisms underlying glucose regulation of glucagon secretion are poorly understood and likely involve both α-cell-intrinsic and intraislet paracrine signaling. Among paracrine factors, glucose-stimulated release of the GABA metabolite γ-hydroxybutyric acid (GHB) from pancreatic ß-cells might mediate glucose suppression of glucagon release via GHB receptors on α-cells. However, the direct effects of GHB on α-cell signaling and glucagon release have not been investigated. Here, we found that GHB (4-10 µm) lacked effects on the cytoplasmic concentrations of the secretion-regulating messengers Ca2+ and cAMP in mouse α-cells. Glucagon secretion from perifused mouse islets was also unaffected by GHB at both 1 and 7 mm glucose. The GHB receptor agonist 3-chloropropanoic acid and the antagonist NCS-382 had no effects on glucagon secretion and did not affect stimulation of secretion induced by a drop in glucose from 7 to 1 mm Inhibition of endogenous GHB formation with the GABA transaminase inhibitor vigabatrin also failed to influence glucagon secretion at 1 mm glucose and did not prevent the suppressive effect of 7 mm glucose. In human islets, GHB tended to stimulate glucagon secretion at 1 mm glucose, an effect mimicked by 3-chloropropanoic acid. We conclude that GHB does not mediate the inhibitory effect of glucose on glucagon secretion.

Does sodium oxybate inhibit brain dopamine release in humans? An exploratory neuroimaging study.

OBJECTIVE: To establish in an exploratory neuroimaging study whether γ-hydroxybutyrate (sodium oxybate [SO]), a sedative, anti-narcoleptic drug with abuse potential, transiently inhibits striatal dopamine release in the human. METHODS: Ten healthy participants (30 years; 6M, 4F) and one participant with narcolepsy received a baseline positron emission tomography scan of [C-11]raclopride, a D2/3 dopamine receptor radioligand sensitive to dopamine occupancy, followed approximately one week later by an oral sedative 3g dose of SO and two [C-11]raclopride scans (1 h, 7 h post SO). Plasma SO levels and drowsiness duration were assessed. RESULTS: No significant changes were detected in [C-11]raclopride binding in striatum overall 1 or 7 h after SO, but a small non-significant increase in [C-11]raclopride binding, implying decreased dopamine occupancy, was noted in limbic striatal subdivision at one hour (+6.5%; p uncorrected = 0.045; +13.2%, narcolepsy participant), returning to baseline at 7 h. A positive correlation was observed between drowsiness duration and percent change in [C-11]raclopride binding in limbic striatum (r = 0.73; p = 0.017). CONCLUSIONS: We did not find evidence in this sample of human subjects of a robust striatal dopamine change, as was reported in non-human primates. Our preliminary data, requiring extension, suggest that a 3g sedative SO dose might cause slight transient inhibition of dopamine release in limbic striatum.

Drug-drug interaction between diclofenac and gamma-hydroxybutyric acid.

Gamma hydroxybutyric acid (GHB) has been approved clinically to treat excessive daytime sleepiness and cataplexy in patients with narcolepsy, alcohol and opioid withdrawal, and as an anesthetic. The use of GHB clinically is limited due to its high abuse potential. The absorption, clearance and tissue uptake of GHB is mediated by proton-dependent and sodium-coupled monocarboxylate transporters (MCTs and SMCTs) and inhibition of these transporters may result in a change in GHB pharmacokinetics and pharmacodynamics. Previous studies have reported that non-steroidal anti-inflammatory drugs (NSAIDs) may inhibit these monocarboxylate transporters. Therefore, the purpose of this work was to analyze the interaction between GHB (at a dose of 600 mg/kg i. v.) and the NSAID, diclofenac, by examining the effects of this drug on the in vivo pharmacokinetics and pharmacodynamics in rat studies. The pharmacodynamic effect evaluated was respiratory depression, a measure of toxicity observed by GHB at this dose. There was an improvement in the respiratory rate with diclofenac administration suggesting an effect of diclofenac on GHB toxicity. In vitro studies with rat blood brain endothelial cells (RBE4) that express MCT1 indicated that diclofenac can inhibit GHB transport with an IC50 of 10.6 µM at pH 7.4. In vivo studies found a decrease in brain GHB concentrations and a decrease in the brain-to-plasma concentration ratio following diclofenac treatment. With this study we can conclude that diclofenac and potentially other NSAIDs can inhibit the transport of GHB into the brain, therefore decreasing GHB's pharmacodynamic effects and toxicity.

The challenge of post-mortem GHB analysis: storage conditions and specimen types are both important.

BACKGROUND: For the interpretation of concentrations of gamma-hydroxybutyrate (GHB) in post-mortem specimens, a possible increase due to post-mortem generation in the body and in vitro has to be considered. The influence of different storage conditions and the specimen type was investigated. METHOD AND MATERIAL: Post-mortem GHB concentrations in femoral venous blood (VB), heart blood (HB), serum (S) from VB, urine (U), cerebrospinal fluid (CSF) and vitreous humour (VH) were determined by gas chromatography-mass spectrometry after derivatisation. Various storage conditions, that is 4 °C or room temperature (RT) and the addition of sodium fluoride (NaF), were compared during storage up to 30 days. Additionally, bacterial colonisation was determined by mass spectrometry fingerprinting. RESULTS: Twenty-six cases without involvement of exogenous GHB were examined. GHB concentrations (by specimen) at day 0 were 3.9-22.1 mg/L (VB), 6.6-33.3 mg/L (HB), < 0.5-18.1 mg/L (U), 1.1-10.4 mg/L (CSF) and 1.7-22.0 mg/L (VH). At 4 °C, concentrations increased at day 30 to 5.6-74.5 mg/L (VB), 4.6-76.5 mg/L (HB) and < 0.5-21.3 mg/L (U). At RT, concentrations rose to < 0.5-38.5 mg/L (VB), 1.2-94.6 mg/L (HB) and < 0.5-37.5 mg/L (U) at day 30. In CSF, at RT, an increase up to < 0.5-21.2 mg/L was measured, and at 4 °C, a decrease occurred (< 0.5-6.5 mg/L). GHB concentrations in VH remained stable at both temperatures (1.2-20.9 mg/L and < 0.5-26.2 mg/L). The increase of GHB in HB samples with NaF was significantly lower than that without preservation. No correlation was found between the bacterial colonisation and extent of GHB concentration changes. CONCLUSION: GHB concentrations can significantly increase in post-mortem HB, VB and U samples, depending on storage time, temperature and inter-individual differences. Results in CSF, VH, S and/or specimens with NaF are less affected.

Demographic and Clinical Characteristics of Regular GHB-Users with and without GHB-Induced Comas.

BACKGROUND: Gamma hydroxybutyric acid (GHB) has been used recreationally for nearly three decades and its chronic use is frequently associated with serious adverse events including GHB-intoxication with GHB-induced comas. Moreover, despite its low prevalence, the number of individuals with GHB-use disorders is steadily increasing. However, the risk-factors associated with chronic GHB-use or the development of a GHB-use disorders remain poorly understood. Purpose: This study aims to profile two types of GHB-users, those with and those without GHB-induced comas. Methods: We included 27 GHB users with ≥4 GHB-induced comas (GHB-Coma), 27 GHB users without a coma (GHB-NoComa), and 27 polydrug users who never used GHB (No-GHB). Participants completed self-reported questionnaires in order to assess their demographic and clinical features, and their use profile of GHB and other drugs. Results: The typical GHB user in our sample was young, single, living alone, well-educated, and a student. The GHB-Coma group had lower self-control and reported higher negative affect than the GHB-NoComa group. GHB-Coma participants were heavier GHB users and mostly used GHB alone at home, whereas the GHB-NoComa group mostly used GHB with friends and in nightclubs. Remarkably, the majority of participants were not concerned about potential neurocognitive impairments induced by GHB-intoxication and/or GHB-induced comas. Conclusion: In this assessment, different profiles for recreational users with and without GHB-induced comas were well expressed. Their description contributes to a better understanding of the risk factors associated with recreational GHB-use, GHB-induced coma, and the development of GHB-use disorders.

Lack of evidence for synaptic high-affinity γ-hydroxybutyric acid (GHB) transport in rat brain synaptosomes and 11 Na+ -dependent SLC neurotransmitter transporters.

γ-Hydroxybutyric acid (GHB) is an endogenous compound proposed to act as a neurotransmitter. Na+ -dependent, high-affinity GHB transport has long been considered important evidence supporting this hypothesis. However, the molecular identity of such a high-affinity transporter remains unknown. In this study, we sought to identify and characterize GHB synaptic transport through a series of studies using both native and recombinant systems with the ultimate aim of providing evidence to clarify the proposed role of GHB as a neurotransmitter in the mammalian brain. Native [3 H]GHB transport was studied in isolated rat brain synaptosomes and compared to synaptic membranes. As a targeted approach, GHB was also screened against a panel of Na+ -dependent SLC6 neurotransmitter transporters recombinantly expressed in Xenopus laevis oocytes or tsA201 cells. Finally, the low-affinity GHB transporters, MCT1/2 and SMCT1, were probed as GHB transporters in L-[14 C]lactate uptake assays in synaptosomes. We found no evidence of high-affinity [3 H]GHB transport in purified rat brain cortical or striatal synaptosomes or at any of the 11 SLC6 transporters tested. Instead, our results indicate the binding of [3 H]GHB to an unidentified membrane component, distinct from any of the known GHB targets. In accordance with others, we found that GHB and the analog 3-hydroxycyclopent-1-enecarboxylic acid (HOCPCA) can, in millimolar concentrations, inhibit L-[14 C]lactate uptake at MCT1 and/or MCT2 and that this also can occur in synaptosomes. In conclusion, through a variety of in vitro pharmacological studies, we were unsuccessful in identifying a specific synaptic high-affinity transporter for GHB. Our findings emphasize the need to reevaluate GHB's role as a potential neurotransmitter. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.

Recreational use of GHB is associated with alterations of resting state functional connectivity of the central executive and default mode networks.

Gamma-hydroxybutyrate acid (GHB) is a recreational drug with a high addictive potential. Severe side effects such as GHB-induced coma are common and linked to increased emergency room attendances. Task-based functional-imaging studies have revealed an association between the regular use of GHB and multiple GHB-induced comas, and altered neurocognitive function. However the effects of multiple GHB-induced comas and regular GHB-use on intrinsic brain connectivity during rest remain unknown. The study population consisted of 23 GHB-users with ≥4 GHB-induced comas (GHB-Coma), 22 GHB-users who never experienced a GHB-induced coma (GHB-NoComa) and 24 polydrug users who never used GHB (No-GHB). Resting-state scans were collected to assess resting-state functional-connectivity within and between the default mode network (DMN), the bilateral central executive network (CEN) and the salience network (SN). The GHB-NoComa group showed decreased rsFC of the right CEN with a region in the anterior cingulate cortex (pFWE = 0.048) and decreased rsFC between the right CEN and the DMN (pFWE = 0.048) when compared with the No-GHB group. These results suggest that regular GHB-use is associated with decreased rsFC within the right CEN and between the right CEN and the DMN. The presence of multiple GHB-induced comas is not associated with (additional) alterations in rsFC.

Nocturnal Gamma-Hydroxybutyrate Reduces Cortisol-Awakening Response and Morning Kynurenine Pathway Metabolites in Healthy Volunteers.

BACKGROUND: Gamma-hydroxybutyrate (GHB; or sodium oxybate) is an endogenous GHB-/gamma-aminobutyric acid B receptor agonist. It is approved for application in narcolepsy and has been proposed for the potential treatment of Alzheimer's disease, Parkinson's disease, fibromyalgia, and depression, all of which involve neuro-immunological processes. Tryptophan catabolites (TRYCATs), the cortisol-awakening response (CAR), and brain-derived neurotrophic factor (BDNF) have been suggested as peripheral biomarkers of neuropsychiatric disorders. GHB has been shown to induce a delayed reduction of T helper and natural killer cell counts and alter basal cortisol levels, but GHB's effects on TRYCATs, CAR, and BDNF are unknown. METHODS: Therefore, TRYCAT and BDNF serum levels, as well as CAR and the affective state (Positive and Negative Affect Schedule [PANAS]) were measured in the morning after a single nocturnal dose of GHB (50 mg/kg body weight) in 20 healthy male volunteers in a placebo-controlled, balanced, randomized, double-blind, cross-over design. RESULTS: In the morning after nocturnal GHB administration, the TRYCATs indolelactic acid, kynurenine, kynurenic acid, 3-hydroxykynurenine, and quinolinic acid; the 3-hydroxykynurenine to kynurenic acid ratio; and the CAR were significantly reduced (P < 0.05-0.001, Benjamini-Hochberg corrected). The quinolinic acid to kynurenic acid ratio was reduced by trend. Serotonin, tryptophan, and BDNF levels, as well as PANAS scores in the morning, remained unchanged after a nocturnal GHB challenge. CONCLUSIONS: GHB has post-acute effects on peripheral biomarkers of neuropsychiatric disorders, which might be a model to explain some of its therapeutic effects in disorders involving neuro-immunological pathologies. This study was registered at ClinicalTrials.gov as NCT02342366.

Increased use of illicit drugs in a Dutch cluster headache population.

INTRODUCTION: Many patients with cluster headache report use of illicit drugs. We systematically assessed the use of illicit drugs and their effects in a well-defined Dutch cluster headache population. METHODS: In this cross-sectional explorative study, 756 people with cluster headache received a questionnaire on lifetime use and perceived effects of illicit drugs. Results were compared with age and sex-matched official data from the Dutch general population. RESULTS: Compared to the data from the general population, there were more illicit drug users in the cluster headache group (31.7% vs. 23.8%; p < 0.01). Reduction in attack frequency was reported by 56% (n = 22) of psilocybin mushroom, 60% (n = 3) of lysergic acid diethylamide and 50% (n = 2) of heroin users, and a decreased attack duration was reported by 46% (n = 18) of PSI, 50% (n = 2) of heroin and 36% (n = 8) of amphetamine users. CONCLUSION: In the Netherlands, people with cluster headache use illicit drugs more often than the general population. The question remains whether this is due to an actual alleviatory effect, placebo response, conviction, or common pathophysiological background between cluster headache and addictive behaviours such as drug use.

Maternal glutamine supplementation in murine succinic semialdehyde dehydrogenase deficiency, a disorder of γ-aminobutyric acid metabolism.

Murine succinic semialdehyde dehydrogenase deficiency (SSADHD) manifests with high concentrations of γ-aminobutyric acid (GABA) and γ-hydroxybutyrate (GHB) and low glutamine in the brain. To understand the pathogenic contribution of central glutamine deficiency, we exposed aldh5a1-/- (SSADHD) mice and their genetic controls (aldh5a1+/+ ) to either a 4% (w/w) glutamine-containing diet or a glutamine-free diet from conception until postnatal day 30. Endpoints included brain, liver and blood amino acids, brain GHB, ataxia scores, and open field testing. Glutamine supplementation did not improve aldh5a1-/- brain glutamine deficiency nor brain GABA and GHB. It decreased brain glutamate but did not change the ratio of excitatory (glutamate) to inhibitory (GABA) neurotransmitters. In contrast, glutamine supplementation significantly increased brain arginine (30% for aldh5a1+/+ and 18% for aldh5a1-/- mice), and leucine (12% and 18%). Glutamine deficiency was confirmed in the liver. The test diet increased hepatic glutamate in both genotypes, decreased glutamine in aldh5a1+/+ but not in aldh5a1-/- , but had no effect on GABA. Dried bloodspot analyses showed significantly elevated GABA in mutants (approximately 800% above controls) and decreased glutamate (approximately 25%), but no glutamine difference with controls. Glutamine supplementation did not impact blood GABA but significantly increased glutamine and glutamate in both genotypes indicating systemic exposure to dietary glutamine. Ataxia and pronounced hyperactivity were observed in aldh5a1-/- mice but remained unchanged by the diet intervention. The study suggests that glutamine supplementation improves peripheral but not central glutamine deficiency in experimental SSADHD. Future studies are needed to fully understand the pathogenic role of brain glutamine deficiency in SSADHD.

Differentiation of endogenous and exogenous γ-Hydroxybutyrate in rat and human urine by GC/C/IRMS.

Gamma (γ)-hydroxybutyric acid (GHB) has been reported to be an endogenous compound in the mammalian brain. It used to treat symptoms of alcohol, opioid, and drug withdrawal and cataplexy of narcolepsy. However, it is often used for criminal purposes because it is colorless, tasteless, and has short half-life. For this reason, there is a need for a method of distinguishing between endogenous and exogenous GHB administration. Therefore, urine from rat before administration of GHB and GHB urine after the single intraperitoneal injection of GHB as 30 mg/100 g were collected from Sprague-Dawley rats (7 weeks old, 10 males and females). Negative control urine, urine from individuals suspected of taking GHB, and urine from victims who were GHB-involved crime were collected. In urine samples, GHB was extracted with two-step SPE and collected fraction was derivatized and analyzed by GC/MS and GC/C/IRMS. In GC/MS and GC/C/IRMS analysis of rat urine, there was a statistically significant difference between urine from rat before administration of GHB and GHB rat urine (p < 0.05). In GC/MS analysis of human urine samples, there was no significant difference among human urine groups (negative control, suspects' urine, and victims' urine), but in GC/C/IRMS analysis of human urine samples, there was a statistically significant difference among human urine groups (p = 0.0001). Through these results, GC/C/IRMS can be more effective tool to identify endogenous and exogenous GHB in urine than GC/MS. This study can build a drug management system in forensic investigation agency and offer interpretation method to forensic science and court.

Novel mutations in two unrelated Italian patients with SSADH deficiency.

Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a rare autosomal recessive disorder of γ-aminobutyric acid (GABA) catabolism caused by mutations in the gene coding for succinic semialdehyde dehydrogenase (ALDH5A1). The abnormal levels of GHB detected in the brain and in all physiological fluids of SSADHD patients represent a diagnostic biochemical hallmark of the disease. Here we report on the clinical and molecular characterization of two unrelated Italian patients and the identification of two novel mutations: a 22 bp DNA duplication in exon 1, c.114_135dup, p.(C46AfsX97), and a non-sense mutation in exon 10, c.1429C > T, p.(Q477X). The two patients showed very different clinical phenotypes, coherent with their age. These findings enrich the characterization of SSADHD families and contribute to the knowledge on the progression of the disease.

[Course and complications of GHB detoxification treatment: a 1-year case series]. / Verlauf und Komplikationen des GHB-Entzuges: eine 1­Jahres-Fallserie.

BACKGROUND: Gamma-hydroxybutyrate (GHB) and its precursors have gained popularity over the last decade as a drug in the party and club scene; however, the clinical knowledge of these substances is low. In the literature there have been case reports of severe dependence and withdrawal but there is a lack of systematic knowledge about the clinical course and complications of detoxification treatment. OBJECTIVE: The aim of this article is to evaluate the prevalence, treatment course, complications and compliance of GHB patients seeking inpatient qualified detoxification treatment (QDT). METHODS: A retrospective evaluation of the hospital charts of all patients admitted to this clinic in 2017 for QDT of GHB. The Jewish Hospital in Berlin (Jüdisches Krankenhaus Berlin) provides specialized inpatient units for addictive diseases and a general intensive care unit. The control population came from a prospective study of all patients with addictive diseases who were treated in the same hospital in 2012. RESULTS: In 2017 a total of 18 patients with GHB addiction were treated in this hospital. This corresponds to a 1­year prevalence of 2.28% of all addictive diseases in this year. During detoxification treatment 52% of the GHB patients had to be temporarily transferred to the intensive care unit, 5% had to be temporarily mechanically ventilated and 26% suffered from withdrawal delirium. Of the patients 42% terminated treatment prematurely against medical advice. CONCLUSION: Withdrawal treatment from GHB is a severe and potentially dangerous condition, the prevalence of complications was higher than for most other drugs and the rate of intensive care and withdrawal delirium was very high. Further studies are urgently needed with the aim of reducing the complication rates of GHB withdrawal and enhancing therapy adherence.