Serum resistin levels in children with primary snoring

Primary Snoring (PS) has been positioned at the milder end of the Sleep-Disordered Breathing severity continuum characterized by snoring and it is usually underestimated. PS is defined as snoring without apnea, frequent arousals, or gas exchange abnormalities and recent studies demonstrated that children with PS have increased blood pressure and reduced arterial distensibility. The association between adipokines and SDB has been recently investigated, though most of the studies were focused on OSAS where intermittent hypoxia characterizing the disease may lead to an inflammatory cascade and to the release of several adipokines, contributing to oxidative stress. Resistin, initially described s an adipokine increasing insulin resistance, has been recently identified as a novel important member of the cytokine family involved in the regulation of inflammation. The aim of our study was to investigate circulating resistin levels in normal weight children with PS. Sixty-five children of normal weight aged between 4 and 14 years of age were selected for habitual snoring. Children with positive polysomnography were excluded from the study. Serum resistin levels were detected in all children with PS. Thirty-three healthy non-snorer children with similar age, sex and BMI were selected as a control group. A significantly higher level of resistin was observed in patients with PS compared to the control group (4.67±1.91 ng/ml vs 3.98±1.58 ng/ml; p<0.01). Patients with inconclusive pulse oximetry showed significantly higher resistin levels than those with negative recordings recordings (5.29±1.91 ng/ml vs 4.20±1.93 ng/ml; p<0.008). Moreover, there was a significant increasing trend between sieric adipokine level and the frequency of snoring (p<0.006). Our results suggest that systemic inflammation and oxidative stress may also play a significant role in the pathophysiology of PS.

The dual FAAH/MAGL inhibitor JZL195 has enhanced effects on endocannabinoid transmission and motor behavior in rats as compared to those of the MAGL inhibitor JZL184

The biological actions of the endocannabinoids anandamide and 2-arachidonoyl glycerol (2-AG) are terminated by enzymatic hydrolysis of these lipids via fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), respectively. While several selective FAAH inhibitors have been developed and characterized in vitro and in vivo, none of the initial MAGL blockers have shown adequate potency and specificity for in vivo applications. More recently, a selective MAGL inhibitor, JZL184, has been shown to produce a long-lasting elevation of brain 2-AG, as well as cannabinoid-like behavioral responses in mice. However, its effectiveness in rats remains controversial. Indeed, although JZL184 can elicit behavioral responses that are mediated, at least in part, via activation of cannabinoid CB1 receptors, several reports indicate that this compound does not alter 2-AG levels in this species. In this study we compared the behavioral and neurochemical effects of JZL 184 with those of the dual FAAH/MAGL inhibitor JZL195, and showed that systemic administration of the former can selectively elevate brain 2-AG in rats and produce motor suppression through a CB1-independent mechanism. These findings indicate that, despite its lower potency against rat MAGL, JZL184 can be used to enhance 2-AG transmission and elicit behavioral responses in rodents.

Phencyclidine-induced social withdrawal results from deficient stimulation of cannabinoid CB₁ receptors: implications for schizophrenia

The neuronal mechanisms underlying social withdrawal, one of the core negative symptoms of schizophrenia, are not well understood. Recent studies suggest an involvement of the endocannabinoid system in the pathophysiology of schizophrenia and, in particular, of negative symptoms. We used biochemical, pharmacological, and behavioral approaches to investigate the role played by the endocannabinoid system in social withdrawal induced by sub-chronic administration of phencyclidine (PCP). Pharmacological enhancement of endocannabinoid levels via systemic administration of URB597, an inhibitor of endocannabinoid degradation, reversed social withdrawal in PCP-treated rats via stimulation of CB1 receptors, but reduced social interaction in control animals through activation of a cannabinoid/vanilloid-sensitive receptor. In addition, the potent CB agonist CP55,940 reversed PCP-induced social withdrawal in a CB₁-dependent manner, whereas pharmacological blockade of CB₁ receptors by either AM251 or SR141716 reduced the time spent in social interaction in control animals. PCP-induced social withdrawal was accompanied by a decrease of anandamide (AEA) levels in the amygdala and prefrontal cortex, and these deficits were reversed by URB597. As CB₁ receptors are predominantly expressed on GABAergic interneurons containing the anxiogenic peptide cholecystokinin (CCK), we also examined whether the PCP-induced social withdrawal resulted from deficient CB₁-mediated modulation of CCK transmission. The selective CCK2 antagonist LY225910 blocked both PCP- and AM251-induced social withdrawal, but not URB597 effect in control rats. Taken together, these findings indicate that AEA-mediated activation of CB₁ receptors is crucial for social interaction, and that PCP-induced social withdrawal results from deficient endocannabinoid transmission.

Exercise-induced endocannabinoid signaling is modulated by intensity

Endocannabinoids (eCB) are endogenous ligands for cannabinoid receptors that are densely expressed in brain networks responsible for reward. Recent work shows that exercise activates the eCB system in humans and other mammals, suggesting eCBs are partly responsible for the reported improvements in mood and affect following aerobic exercise in humans. However, exercise-induced psychological changes reported by runners are known to be dependent on exercise intensity, suggesting that any underlying molecular mechanism should also change with varying levels of exercise intensity. Here, we examine circulating levels of eCBs following aerobic exercise (treadmill running) in recreationally fit human runners at four different intensities. We show that eCB signaling is indeed intensity dependent, with significant changes in circulating eCBs observed following moderate intensities only (very high and very low intensity exercises do not significantly alter circulating eCB levels). Our results are consistent with intensity-dependent psychological state changes with exercise and therefore support the hypothesis that eCB activity is related to neurobiological effects of exercise. Thus, future studies examining the role of exercise-induced eCB signaling on neurobiology or physiology must take exercise intensity into account.

Novel codrugs with GABAergic activity for dopamine delivery in the brain

This study investigates the use of codrugs of the GABAergic agent 2-phenyl-imidazo[1,2-a]pyridinacetamide and dopamine (DA) or ethyl ester L-Dopa (LD) as a strategy to deliver DA and simultaneously activate GABA-receptors in the brain. For this purpose, both DA and LD ethyl ester were linked by carbamate bond to imidazo[1,2-a]pyridine acetamide moieties to yield two DA- and two LD-imidazopyridine derivatives. These compounds were evaluated in vitro to assess their stability, binding affinities and cell membrane transport, and in vivo to assess their bio-availability via microdialysis studies. The two DA derivatives were adequately stable in buffered solution, but underwent cleavage in diluted human serum. By contrast, the LD derivatives were unstable in buffered solution. Receptor binding studies showed that the DA-imidazopyridine carbamates had binding affinity for benzodiazepine receptors in the nanomolar range. Brain microdialysis experiments indicated that intraperitoneal administration of the DA derivatives sustained DA levels in rat striatum over a 4-h period. These results suggest that DA-imidazopyridine carbamates are new DA codrugs with potential application for DA replacement therapy.

Anti-dyskinetic mechanisms of amantadine and dextromethorphan in the 6-OHDA rat model of Parkinson's disease: role of NMDA vs. 5-HT1A receptors

Amantadine and dextromethorphan suppress levodopa (L-DOPA)-induced dyskinesia (LID) in patients with Parkinson's disease (PD) and abnormal involuntary movements (AIMs) in the unilateral 6-hydroxydopamine (6-OHDA) rat model. These effects have been attributed to N-methyl-d-aspartate (NMDA) antagonism. However, amantadine and dextromethorphan are also thought to block serotonin (5-HT) uptake and cause 5-HT overflow, leading to stimulation of 5-HT(1A) receptors, which has been shown to reduce LID. We undertook a study in 6-OHDA rats to determine whether the anti-dyskinetic effects of these two compounds are mediated by NMDA antagonism and/or 5-HT(1A) agonism. In addition, we assessed the sensorimotor effects of these drugs using the Vibrissae-Stimulated Forelimb Placement and Cylinder tests. Our data show that the AIM-suppressing effect of amantadine was not affected by the 5-HT(1A) antagonist WAY-100635, but was partially reversed by the NMDA agonist d-cycloserine. Conversely, the AIM-suppressing effect of dextromethorphan was prevented by WAY-100635 but not by d-cycloserine. Neither amantadine nor dextromethorphan affected the therapeutic effects of L-DOPA in sensorimotor tests. We conclude that the anti-dyskinetic effect of amantadine is partially dependent on NMDA antagonism, while dextromethorphan suppresses AIMs via indirect 5-HT(1A) agonism. Combined with previous work from our group, our results support the investigation of 5-HT(1A) agonists as pharmacotherapies for LID in PD patients.

Wired to run: exercise-induced endocannabinoid signaling in humans and cursorial mammals with implications for the 'runner's high'

Humans report a wide range of neurobiological rewards following moderate and intense aerobic activity, popularly referred to as the 'runner's high', which may function to encourage habitual aerobic exercise. Endocannabinoids (eCBs) are endogenous neurotransmitters that appear to play a major role in generating these rewards by activating cannabinoid receptors in brain reward regions during and after exercise. Other species also regularly engage in endurance exercise (cursorial mammals), and as humans share many morphological traits with these taxa, it is possible that exercise-induced eCB signaling motivates habitual high-intensity locomotor behaviors in cursorial mammals. If true, then neurobiological rewards may explain variation in habitual locomotor activity and performance across mammals. We measured circulating eCBs in humans, dogs (a cursorial mammal) and ferrets (a non-cursorial mammal) before and after treadmill exercise to test the hypothesis that neurobiological rewards are linked to high-intensity exercise in cursorial mammals. We show that humans and dogs share significantly increased exercise-induced eCB signaling following high-intensity endurance running. eCB signaling does not significantly increase following low-intensity walking in these taxa, and eCB signaling does not significantly increase in the non-cursorial ferrets following exercise at any intensity. This study provides the first evidence that inter-specific variation in neurotransmitter signaling may explain differences in locomotor behavior among mammals. Thus, a neurobiological reward for endurance exercise may explain why humans and other cursorial mammals habitually engage in aerobic exercise despite the higher associated energy costs and injury risks, and why non-cursorial mammals avoid such locomotor behaviors.

The cannabinoid agonist WIN55212-2 decreases L-DOPA-induced PKA activation and dyskinetic behavior in 6-OHDA-treated rats

Chronic Levodopa (L-DOPA), the gold standard therapy for Parkinson's disease (PD), causes disabling motor complications (dyskinesias) that are associated with changes in the activity of striatal protein kinase A (PKA) and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32). In this study, we showed that systemic administration of the cannabinoid agonist WIN55212-2 ameliorated L-DOPA-induced abnormal involuntary movements (AIMs) in the 6-OHDA rat model of PD and reversed L-DOPA-induced PKA hyperactivity via a CB(1)-mediated mechanism. This effect was accompanied by increased phosphorylation of DARPP-32 at threonine 34, which was partially blocked by CB(1) antagonism. Striatal PKA activity was positively correlated with the severity of L-DOPA-induced axial and limb dyskinesias, suggesting a role for the cAMP/PKA signaling pathway in the expression of these motor disturbances. Our results indicate that activation of CB(1) receptors, as well as reduction of striatal PKA hyperactivity, might be an effective strategy for the treatment of L-DOPA-induced dyskinesias.

Androgens exacerbate motor asymmetry in male rats with unilateral 6-hydroxydopamine lesion

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by dopamine neuron loss in the nigrostriatal pathway that shows greater incidence in men than women. The mechanisms underlying this gender bias remain elusive, although one possibility is that androgens may increase dopamine neuronal vulnerability to oxidative stress. Motor impairment can be modeled in rats receiving a unilateral injection of 6-hydroxydopamine (6-OHDA), a neurotoxin producing nigrostriatal degeneration. To investigate the role of androgens in PD, we compared young (2 months) and aged (24 months) male rats receiving gonadectomy (GDX) and their corresponding intact controls. One month after GDX, rats were unilaterally injected with 6-OHDA, and their motor impairment and asymmetry were assessed 2 weeks later using the cylinder test and the amphetamine-induced rotation test. Plasma samples were also collected to assess the concentration of testosterone and advanced oxidation protein products, a product of oxidative stress. GDX decreased lesion-induced asymmetry along with oxidative stress and increased amphetamine-induced rotations. These results show that GDX improves motor behaviors by decreasing motor asymmetry in 6-OHDA-treated rats, an effect that may be ascribed to increased release of striatal dopamine and decreased oxidative stress. Collectively, the data support the hypothesis that androgens may underlie the gender bias observed in PD.

A synthetic cannabinoid agonist promotes oligodendrogliogenesis during viral encephalitis in rats

Chronic CNS infection by several families of viruses can produce deficits in prefrontal cortex (PFC) and striatal function. Cannabinoid drugs have been long known for their anti-inflammatory properties and their ability to modulate adult neuro and gliogenesis. Therefore, we explored the effects of systemic administration of the cannabinoid agonist WIN55,212-2(WIN) on prefrontal cortex (PFC) and striatal cytogenesis in a viral model of CNS injury and inflammation based on Borna Disease (BD) virus encephalitis. Active BrdU(+) progenitor populations were significantly decreased 1 week after BrdU labeling in BD rats [p<0.001 compared to uninfected (NL) controls] while less than 5% of BrdU(+) cells colabeled for BDV protein. Systemic WIN (1mg/kg i.p. twice daily×7 days) increased the survival of BrdU(+) cells in striatum (p<0.001) and PFC of BD rats, with differential regulation of labeled oligodendroglia precursors vs microglia/macrophages. WIN increased the percentage of BrdU(+) oligodendrocyte precursor cells and decreased BrdU(+) ED-1-labeled phagocytic cells, without producing pro- or antiviral effects. BDV infection decreased the levels of the endocannabinoid anandamide (AEA) in striatum (p<0.05 compared to NL rats), whereas 2-AG levels were unchanged. Our findings indicate that: 1) viral infection is accompanied by alterations of AEA transmission in the striatum, but new cell protection by WIN appears independent of its effect on endocannabinoid levels; and 2) chronic WIN treatment alters the gliogenic cascades associated with CNS injury, promoting oligodendrocyte survival. Limiting reactive gliogenesis and macrophage activity in favor of oliogodendroglia development has significance for demyelinating diseases. Moreover, the ability of cannabinoids to promote the development of biologically supportive or symbiotic oligodendroglia may generalize to other microglia-driven neurodegenerative syndromes including NeuroAIDS and diseases of aging.

Androgens induce dopaminergic neurotoxicity via caspase-3-dependent activation of protein kinase Cdelta

Aged men have a greater incidence of Parkinson's disease (PD) than women. PD is a neurodegenerative condition associated with the loss of dopamine neurons in the nigrostriatal pathway. This study examined the neurotoxic effects of androgens in a dopaminergic cell line (N27 cells) and the downstream signaling pathways activated by androgens. Treatment of N27 cells with testosterone- and dihydrotestosterone-induced mitochondrial dysfunction, protein kinase C (PKC)-delta cleavage, and apoptosis in dopaminergic neuronal cells. Inhibition of caspase-3 prevented the cleavage of PKCdelta from the full-length element to the catalytic fragment and apoptosis in N27 cells, suggesting that androgen-induced apoptosis is mediated by caspase-3-dependent activation of PKCdelta. Androgen-induced apoptosis may be specific to dopamine neurons as evidenced by a lack of testosterone-induced apoptosis in GnRH neurons. These results support a neurotoxic consequence of testosterone on dopaminergic neurons and may provide insight into the gender bias found in PD.

A case of ARDS associated with influenza A - H1N1 infection treated with extracorporeal respiratory support

After the first outbreak identified in Mexico in late March 2009, influenza A sustained by a modified H1N1 virus ("swine flu") rapidly spread to all continents. This article describes the first Italian case of life-threatening ARDS associated with H1N1 infection, treated with extracorporeal respiratory assistance (venovenous extracorporeal membrane oxygenation [ECMO]). A 24-year-old, previously healthy man was admitted to the Intensive Care Unit (ICU) of the local hospital for rapidly progressive respiratory failure with refractory impairment of gas exchange unresponsive to rescue therapies (recruitment manoeuvres, pronation and nitric oxide inhalation). An extracorporeal respiratory assistance (venovenous ECMO) was performed. It allowed a correction of the respiratory acidosis and made possible the transportation of the patient to the ICU (approximately 150 km from the first hospital). A nasal swab tested positive for H1N1 infection and treatment with oseltamivir was started. The chest computed tomography scan showed bilateral massive, patchy consolidation of lung parenchyma; lab tests showed leukopenia, elevated CPK levels and renal failure. The patient required high dosages of norepinephrine for septic shock and continuous renal replacement therapy. The clinical course was complicated by Pseudomonas aeruginosa superinfection, treated with intravenous and aerosolised colistin. ECMO was withheld after 15 days, while recovery of renal and respiratory function was slower. The patient was discharged from the ICU 34 days after admission. In this case, ECMO was life-saving and made the inter-hospital transfer of the patient possible.

Bacteria isolated from 25 hydatid cysts in sheep, cattle and goats

Bacteria were isolated from 12 of 25 hydatid cysts collected from the lungs and livers of cattle, sheep and goats slaughtered in the province of Messina, Sicily, Italy. Citrobacter freundii was isolated from seven of the cysts, Aeromonas hydrophila from three, Staphylococcus species from two, Salmonella species from two and Escherichia coli and Proteus vulgaris from one.

In vivo pharmacology of endocannabinoids and their metabolic inhibitors: therapeutic implications in Parkinson's disease and abuse liability

This review focuses on the behavioral pharmacology of endogenous cannabinoids (endocannabinoids) and indirect-acting cannabinoid agonists that elevate endocannabinoid tone by inhibiting the activity of metabolic enzymes. Similarities and differences between prototype cannabinoid agonists, endocannabinoids and inhibitors of endocannabinoid metabolism are discussed in the context of endocannabinoid pharmacokinetics in vivo. The distribution and function of cannabinoid and non-CB(1)/CB(2) receptors are also covered, with emphasis on their role in disorders characterized by dopamine dysfunction, such as drug abuse and Parkinson's disease. Finally, evidence is presented to suggest that FAAH inhibitors lack the abuse liability associated with CB(1) agonists, although they may modify the addictive properties of other drugs, such as alcohol.

WIN55,212-2, a cannabinoid receptor agonist, protects against nigrostriatal cell loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson's disease

Parkinson's disease (PD) is characterized by the progressive loss of nigrostriatal dopamine neurons leading to motor disturbances and cognitive impairment. Current pharmacotherapies relieve PD symptoms temporarily but fail to prevent or slow down the disease progression. In this study, we investigated the molecular mechanisms by which the non-selective cannabinoid receptor agonist WIN55,212-2 (WIN) protects mouse nigrostriatal neurons from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity and neuroinflammation. Stereological analyses showed that chronic treatment with WIN (4 mg/kg, intraperitoneal), initiated 24 h after MPTP administration, protected against MPTP-induced loss of tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta independently of CB1 cannabinoid receptor activation. The neuroprotective effect of WIN was accompanied by increased dopamine and 3,4-dihydroxyphenylacetic acid levels in the substantia nigra pars compacta and dorsal striatum of MPTP-treated mice. At 3 days post-MPTP, we found significant microglial activation and up-regulation of CB2 cannabinoid receptors in the ventral midbrain. Treatment with WIN or the CB2 receptor agonist JWH015 (4 mg/kg, intraperitoneal) reduced MPTP-induced microglial activation, whereas genetic ablation of CB2 receptors exacerbated MPTP systemic toxicity. Furthermore, chronic WIN reversed MPTP-associated motor deficits, as revealed by the analysis of forepaw step width and percentage of faults using the inverted grid test. In conclusion, our data indicate that agonism at CB2 cannabinoid receptors protects against MPTP-induced nigrostriatal degeneration by inhibiting microglial activation/infiltration and suggest that CB2 receptors represent a new therapeutic target to slow the degenerative process occurring in PD.

Anandamide elevation in cerebrospinal fluid in initial prodromal states of psychosis

Anandamide is a bioactive lipid binding to cannabinoid receptors. A homeostatic role for anandamide has been suggested in schizophrenia. We investigated its role in initial prodromal states of psychosis. We measured the levels of anandamide and its structural analog oleoylethanolamide in cerebrospinal fluid and serum of patients in the initial prodromal state (n=27) alongside healthy volunteers (n=81) using high-performance liquid chromatograph/mass spectrometry. Cerebrospinal anandamide levels in patients were significantly elevated. Patients with lower levels showed a higher risk for transiting to psychosis earlier. This anandamidergic up-regulation in the initial prodromal course may suggest a protective role of the endocannabinoid system in early schizophrenia.

Evaluation of NMDA receptor models of schizophrenia: divergences in the behavioral effects of sub-chronic PCP and MK-801

The hypothesis of hypo-functionality of NMDA receptors in schizophrenia originates from the observation that administration of the NMDA antagonist phencyclidine (PCP) induces psychotic states that closely resemble schizophrenic symptoms and that persist after drug discontinuation. A large number of animal studies have used PCP and the NMDA antagonist dizocilpine (MK-801) almost interchangeably to model schizophrenia. However, PCP interacts with pharmacological targets other than NMDA receptors that are not affected by MK-801. In addition, although acute administration of either compound produces similar effects in animals, there is little information whether withdrawal from chronic MK-801 causes behavioral deficits that mimic schizophrenia symptoms as in the case of PCP. To clarify this issue, we compared the following behaviors in rats subjected to withdrawal from sub-chronic administration (2 x 7 days) of either PCP (5 mg/kg, i.p.) or MK-801 (0.5 mg/kg, i.p.): (1) working memory in a variable-delayed alternation task in a T-maze, (2) social interaction, and (3) motor activity in response to a (a) novel environment, (b) mild stressor, and (c) d-amphetamine challenge. Withdrawal from sub-chronic PCP caused a delay-dependent impairment of working memory, reduced social interaction and enhanced d-amphetamine-induced motor activity. These results were not replicated in animals sub-chronically treated with MK-801, which displayed only a slight decrease in social interaction. These data suggest that pharmacological antagonism at NMDA receptors is not sufficient to explain the full spectrum of PCP psychotomimetic properties.

Engineering a stable and selective peptide blocker of the Kv1.3 channel in T lymphocytes

Kv1.3 potassium channels maintain the membrane potential of effector memory (T(EM)) T cells that are important mediators of multiple sclerosis, type 1 diabetes mellitus, and rheumatoid arthritis. The polypeptide ShK-170 (ShK-L5), containing an N-terminal phosphotyrosine extension of the Stichodactyla helianthus ShK toxin, is a potent and selective blocker of these channels. However, a stability study of ShK-170 showed minor pH-related hydrolysis and oxidation byproducts that were exacerbated by increasing temperatures. We therefore engineered a series of analogs to minimize the formation of these byproducts. The analog with the greatest stability, ShK-192, contains a nonhydrolyzable phosphotyrosine surrogate, a methionine isostere, and a C-terminal amide. ShK-192 shows the same overall fold as ShK, and there is no evidence of any interaction between the N-terminal adduct and the rest of the peptide. The docking configuration of ShK-192 in Kv1.3 shows the N-terminal para-phosphonophenylalanine group lying at the junction of two channel monomers to form a salt bridge with Lys(411) of the channel. ShK-192 blocks Kv1.3 with an IC(50) of 140 pM and exhibits greater than 100-fold selectivity over closely related channels. After a single subcutaneous injection of 100 microg/kg, approximately 100 to 200 pM concentrations of active peptide is detectable in the blood of Lewis rats 24, 48, and 72 h after the injection. ShK-192 effectively inhibits the proliferation of T(EM) cells and suppresses delayed type hypersensitivity when administered at 10 or 100 microg/kg by subcutaneous injection once daily. ShK-192 has potential as a therapeutic for autoimmune diseases mediated by T(EM) cells.

Functional Sspects of the Endocannabinoid System in Schizophrenia

Introduction:

The endocannabinoid system represents the target for the hallucinogenic Δ9-Tetrahydrocannabinol. It consists of naturally occurring endocannabinoid lipids (eCBs) - of which anandamide is the first characterized example - and their attending CB1 cannabinoid receptors. Activation of CB1 receptors produces intense emotional and cognitive responses, suggesting that dysfunction in the eCB system may contribute to the pathogenesis of mental disorders.

Methods:

We examined levels of anandamide in cerebrospinal fluid (CSF) and serum of healthy volunteers (n=84) and various groups of patients suffering from acute psychiatric disorders (n=180).

Results:

Compared to controls, the levels of anandamide in CSF were significantly elevated in acute, antipsychotic-naïve, first-episode schizophrenic patients (n=47) and negatively correlated with psychotic symptoms. This was reversed by the administration of antipsychotics, which antagonize dopamine D2-like receptors (n=37), but not by those, which preferentially antagonize 5HT2A receptors (n=34). In addition, a significant elevation of anandamide was already apparent in a sample of persons clinically at high risk for developing psychosis (prodromal states, n=27). Furthermore, the levels of anandamide in CSF were found significantly lower in antipsychotic-naïve schizophrenic patients reporting more than 20 times of cannabis use in life when compared to those with no more than 5 times.

Conclusion:

Our results suggest that anandamide release in the central nervous system (CNS) may serve as an adaptive mechanism countering neurotransmitter abnormalities in acute schizophrenia. They indicate that frequent cannabis exposure may down-regulate CNS anandamide signaling in schizophrenia and thereby further impact the course of the disease.