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The humoral arm of innate immunity includes diverse molecules with antibody-like functions, some of which serve as disease severity biomarkers in coronavirus disease 2019 (COVID-19). The present study was designed to conduct a systematic investigation of the interaction of human humoral fluid-phase pattern recognition molecules (PRMs) with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Of 12 PRMs tested, the long pentraxin 3 (PTX3) and mannose-binding lectin (MBL) bound the viral nucleocapsid and spike proteins, respectively. MBL bound trimeric spike protein, including that of variants of concern (VoC), in a glycan-dependent manner and inhibited SARS-CoV-2 in three in vitro models. Moreover, after binding to spike protein, MBL activated the lectin pathway of complement activation. Based on retention of glycosylation sites and modeling, MBL was predicted to recognize the Omicron VoC. Genetic polymorphisms at the MBL2 locus were associated with disease severity. These results suggest that selected humoral fluid-phase PRMs can play an important role in resistance to, and pathogenesis of, COVID-19, a finding with translational implications.

Funder: Biotechnology and Biological Sciences Research Council, Funder: Wellcome Trust, BACKGROUND: Cystic Fibrosis (CF) is a genetic disorder affecting around 1 in every 3000 newborns. In the most common mutation, F508del, the defective anion channel, CFTR, is prevented from reaching the plasma membrane (PM) by the quality check control of the cell. Little is known about how CFTR pharmacological rescue impacts the cell proteome. METHODS: We used high-resolution mass spectrometry, differential ultracentrifugation, machine learning and bioinformatics to investigate both changes in the expression and localization of the human bronchial epithelium CF model (F508del-CFTR CFBE41o-) proteome following treatment with VX-809 (Lumacaftor), a drug able to improve the trafficking of CFTR. RESULTS: The data suggested no stark changes in protein expression, yet subtle localization changes of proteins of the mitochondria and peroxisomes were detected. We then used high-content confocal microscopy to further investigate the morphological and compositional changes of peroxisomes and mitochondria under these conditions, as well as in patient-derived primary cells. We profiled several thousand proteins and we determined the subcellular localization data for around 5000 of them using the LOPIT-DC spatial proteomics protocol. CONCLUSIONS: We observed that treatment with VX-809 induces extensive structural and functional remodelling of mitochondria and peroxisomes that resemble the phenotype of healthy cells. Our data suggest additional rescue mechanisms of VX-809 beyond the correction of aberrant folding of F508del-CFTR and subsequent trafficking to the PM.

S737F is a Cystic Fibrosis (CF) transmembrane conductance regulator (CFTR) missense variant. The aim of our study was to describe the clinical features of a cohort of individuals carrying this variant. In parallel, by exploiting ex vivo functional and molecular analyses on nasal epithelia derived from a subset of S737F carriers, we evaluated its functional impact on CFTR protein as well as its responsiveness to CFTR modulators. We retrospectively collected clinical data of all individuals bearing at least one S737F CFTR variant and followed at the CF Centre of Tuscany region (Italy). Nasal brushing was performed in cooperating individuals. At study end clinical data were available for 10 subjects (mean age: 14 years; range 1–44 years; 3 adult individuals). Five asymptomatic subjects had CF, 2 were CRMS/CFSPID and 3 had an inconclusive diagnosis. Ex vivo analysis on nasal epithelia demonstrated different levels of CF activity. In particular, epithelia derived from asymptomatic CF subjects and from one of the subjects with inconclusive diagnosis showed reduced CFTR activity that could be rescued by treatment with CFTR modulators. On the contrary, in the epithelia derived from the other two individuals with an inconclusive diagnosis, the CFTR-mediated current was similar to that observed in epithelia derived from healthy donors. In vitro functional and biochemical analysis on S737F-CFTR expressed in immortalized bronchial cells highlighted a modest impairment of the channel activity, that was improved by treatment with ivacaftor alone or in combination with tezacaftor/elexacaftor. Our study provide evidence towards the evaluation of CFTR function on ex vivo nasal epithelial cell models as a new assay to help clinicians to classify individuals, in presence of discordance between clinical picture, sweat test and genetic profile.

The advent of Trikafta (Kaftrio in Europe) (a triple-combination therapy based on two correctors—elexacaftor/tezacaftor—and the potentiator ivacaftor) has represented a revolution for the treatment of patients with cystic fibrosis (CF) carrying the most common misfolding mutation, F508del-CFTR. This therapy has proved to be of great efficacy in people homozygous for F508del-CFTR and is also useful in individuals with a single F508del allele. Nevertheless, the efficacy of this therapy needs to be improved, especially in light of the extent of its use in patients with rare class II CFTR mutations. Using CFBE41o- cells expressing F508del-CFTR, we provide mechanistic evidence that targeting the E1 ubiquitin-activating enzyme (UBA1) by TAK-243, a small molecule in clinical trials for other diseases, boosts the rescue of F508del-CFTR induced by CFTR correctors. Moreover, TAK-243 significantly increases the F508del-CFTR short-circuit current induced by elexacaftor/tezacaftor/ivacaftor in differentiated human primary airway epithelial cells, a gold standard for the pre-clinical evaluation of patients’ responsiveness to pharmacological treatments. This new combinatory approach also leads to an improvement in CFTR conductance on cells expressing other rare CF-causing mutations, including N1303K, for which Trikafta is not approved. These findings show that Trikafta therapy can be improved by the addition of a drug targeting the misfolding detection machinery at the beginning of the ubiquitination cascade and may pave the way for an extension of Trikafta to low/non-responding rare misfolded CFTR mutants.

SummaryThe humoral arm of innate immunity includes diverse molecules with antibody-like functions, some of which serve as disease severity biomarkers in COVID-19. The present study was designed to conduct a systematic investigation of the interaction of humoral fluid phase pattern recognition molecules (PRM) with SARS-CoV-2. Out of 10 PRM tested, the long pentraxin PTX3 and Mannose Binding Lectin (MBL) bound the viral Nucleoprotein and Spike, respectively. MBL bound trimeric Spike, including that of variants of concern, in a glycan- dependent way and inhibited SARS-CoV-2 in threein vitromodels. Moreover, upon binding to Spike, MBL activated the lectin pathway of complement activation. Genetic polymorphisms at the MBL locus were associated with disease severity. These results suggest that selected humoral fluid phase PRM can play an important role in resistance to, and pathogenesis of, COVID-19, a finding with translational implications.

BACKGROUND AND PURPOSE: Cystic fibrosis (CF) is a lethal autosomal recessive genetic disease that originates from the defective function of the CF transmembrane conductance regulator (CFTR) protein, a cAMP‐dependent anion channel involved in fluid transport across epithelium. Because small synthetic transmembrane anion transporters (anionophores) can replace the biological anion transport mechanisms, independent of genetic mutations in the CFTR, such anionophores are candidates as new potential treatments for CF. EXPERIMENTAL APPROACH: In order to assess their effects on cell physiology, we have analysed the transport properties of five anionophore compounds, three prodigiosines and two tambjamines. Chloride efflux was measured in large uni‐lamellar vesicles and in HEK293 cells with chloride‐sensitive electrodes. Iodide influx was evaluated in FRT cells transfected with iodide‐sensitive YFP. Transport of bicarbonate was assessed by changes of pH after a NH(4) (+) pre‐pulse using the BCECF fluorescent probe. Assays were also carried out in FRT cells permanently transfected with wild type and mutant human CFTR. KEY RESULTS: All studied compounds are capable of transporting halides and bicarbonate across the cell membrane, with a higher transport capacity at acidic pH. Interestingly, the presence of these anionophores did not interfere with the activation of CFTR and did not modify the action of lumacaftor (a CFTR corrector) or ivacaftor (a CFTR potentiator). CONCLUSION AND IMPLICATIONS: These anionophores, at low concentrations, transported chloride and bicarbonate across cell membranes, without affecting CFTR function. They therefore provide promising starting points for the development of novel treatments for CF.

Anion selective ionophores, anionophores, are small molecules capable of facilitating the transmembrane transport of anions. Inspired in the structure of natural product prodigiosin, four novel anionophores 1a-d, including a 1,2,3-triazole group, were prepared. These compounds proved highly efficient anion exchangers in model phospholipid liposomes. The changes in the hydrogen bond cleft modified the anion transport selectivity exhibited by these compounds compared to prodigiosin and suppressed the characteristic high toxicity of the natural product. Their activity as anionophores in living cells was studied and chloride efflux and iodine influx from living cells mediated by these derivatives was demonstrated. These compounds were shown to permeabilize cellular membranes to halides with efficiencies close to the natural anion channel CFTR at doses that do not compromise cellular viability. Remarkably, optimal transport efficiency was measured in the presence of pH gradients mimicking those found in the airway epithelia of Cystic Fibrosis patients. These results support the viability of developing small molecule anionophores as anion channel protein surrogates with potential applications in the treatment of conditions such as Cystic Fibrosis derived from the malfunction of natural anion transport mechanisms., European Union’s Horizon 2020 research and innovation programme under grant agreement No. 667079, La Marató de TV3 Foundation (20132730), Consejería de Educación de la Junta de Castilla y León (Projects BU340U13 and BU092U16)

Novel treatments for bipolar disorder with improved efficacy and broader spectrum of activity are urgently needed. Glycogen synthase kinase 3β (GSK-3β) has been suggested to be a key player in the pathophysiology of bipolar disorder. A series of novel GSK-3β inhibitors having the common N-[(1-alkylpiperidin-4-yl)methyl]-1H-indazole-3-carboxamide scaffold were prepared taking advantage of an X-ray cocrystal structure of compound 5 with GSK-3β. We probed different substitutions at the indazole 5-position and at the piperidine-nitrogen to obtain potent ATP-competitive GSK-3β inhibitors with good cell activity. Among the compounds assessed in the in vivo PK experiments, 14i showed, after i.p. dosing, encouraging plasma PK profile and brain exposure, as well as efficacy in a mouse model of mania. Compound 14i was selected for further in vitro/in vivo pharmacological evaluation, in order to elucidate the use of ATP-competitive GSK-3β inhibitors as new tools in the development of new treatments for mood disorders.

© 2015 American Chemical Society. Fatty acid ethanolamides such as palmitoylethanolamide (PEA) and oleoylethanolamide (OEA) are lipid-derived mediators that potently inhibit pain and inflammation by ligating type-α peroxisome proliferator-activated receptors (PPAR-α). These bioactive substances are preferentially degraded by the cysteine hydrolase, N-acylethanolamine acid amidase (NAAA), which is highly expressed in macrophages. Here, we describe a new class of β-lactam derivatives that are potent, selective, and systemically active inhibitors of intracellular NAAA activity. The prototype of this class deactivates NAAA by covalently binding the enzymes catalytic cysteine and exerts profound anti-inflammatory effects in both mouse models and human macrophages. This agent may be used to probe the functions of NAAA in health and disease and as a starting point to discover better anti-inflammatory drugs.

We investigated a possible drug efficacy enhancement obtained by combining inactive doses of galantamine and memantine in the scopolamine-induced amnesia model in mice. We evaluated the effects of the two drugs, either alone or in combination, using the spontaneous alternation and object recognition tasks. In both tests, combination of low doses of galantamine (0.1 mg/kg, s.c.) and memantine (0.5 mg/kg, i.p.), which were sub-active per se, rescued the memory impairment induced by scopolamine (1 mg/kg, i.p.). The results suggest that combinations of galantamine and memantine might provide a more effective treatment of memory impairments in cognitive disorders than either drug used alone. Keywords:: neurodegenerative disease, multi-target, memory impairment

The effects of salvinorin A ( Salvia divinorum principal ingredient), a potent κ-opioid natural hallucinogen, on learning and memory were investigated. Wistar rats were tested in the 8-arm radial maze, for object recognition and passive avoidance tasks for spatial, episodic, and aversive memory. Attention was assessed using a latent inhibition task. Salvinorin A (80-640 μg/kg subcutaneous [sc]) did not affect short-term memory, but it impaired spatial long-term memory. Episodic and aversive memories were impaired by salvinorin A (160-640 μg/kg). Memory impairment was blocked by the selective κ-opioid receptor antagonist, nor-binaltorphimine ([nor-B]; 0.5-1 mg/kg, intraperitoneal [ip]). Salvinorin A (160 μg/kg) disrupted latent inhibition, after LiCl treatment, such as reduced sucrose intake, suggesting an attention would result in an impairment of cognitive behavior. These findings demonstrate for the first time that salvinorin A has deleterious effects on learning and memory, through a κ-opioid receptor mechanism.

Marijuana and hashish are the illicit drugs most frequently used by human adolescents. Given the continued neurodevelopment throughout adolescence, adolescents may be more vulnerable than adults to certain neural consequences of heavy marijuana use. This study aimed to assess whether an experimental model of adolescent chronic exposure to Delta9-tetrahydrocannabinol (THC), may induce lasting effects on learning and memory. Adolescent rats have been treated with THC or its vehicle from 35 to 45 postnatal days (PND) and left undisturbed until their adulthood (75 PND) when aversive and spatial memory was assessed using the passive avoidance and radial maze tasks. No alteration was found in aversive memory, but in the radial maze THC pretreated animals exhibited a worse performance than vehicles, suggesting a deficit in spatial working memory. To correlate memory impairment to altered neuroplasticity, level of marker proteins was investigated in the hippocampus, the most relevant area mediating spatial memory. A significant decrease in the astroglial marker glial fibrillar acid protein was found as well as in pre- and postsynaptic protein expression (VAMP2, PSD95) and NMDA receptor levels in pretreated rats. To parallel these changes to alteration in dendritic morphology, Golgi-Cox staining was performed in the hippocampal dentate gyrus. Pretreated rats had a significantly lower total dendritic length and number than vehicles, as well as reduced spine density. Our data suggest that THC pretreated rats may establish less synaptic contacts and/or less efficient synaptic connections throughout the hippocampus and this could represent the molecular underpinning of the cognitive deficit induced by adolescent THC treatment.

Background The recreational drug, Salvinorin A, derived from the plant of Salvia divinorum, is a potent and selective κ-opioid receptor agonist. The abuse of selective k-agonists is a novel phenomenon, the mechanism of which is not fully understood. Methods We investigated salvinorin A given SC on the conditioned place preference (.05–160 μg/kg) and intracerebroventricular (ICV) self-administration (.01–1 μg/infusion) paradigms, in Wistar rats. Results The present results demonstrate the rewarding effects of Salvinorin A in a range of doses between .1 and 40 μg/kg SC for conditioned place preference test and .1–.5 μg/infusion for ICV self-administration. Highest doses (160 μg/kg for conditioned place preference test and 1 μg/infusion for ICV self-administration) were aversive. The rewarding effect was antagonized by intraperitoneal (IP) pretreatment with the cannabinoid CB 1 receptor antagonist, rimonabant [N-piperidino-5-(4-chlorophenyl)1-(2,4-dichloro phenyl)-4 methyl pyrazole 3-carboxamide] (1 mg/kg), and the κ-opioid receptor antagonist, nor-binaltorphimine (nor-BNI) (10 mg/kg). In the shell of nucleus accumbens, dopamine extracellular levels were increased after administration of salvinorin A (40 μg/kg SC), reaching a maximum value of about 150%. Conclusions These data provide the demonstration of the rewarding effects of Salvinorin A through an interaction between κ-opioid and (endo)cannabinoid system in rats.

Background and purpose: It has been suggested that the endocannabinoid system elicits neuroprotection against excitotoxic brain damage. In the present study the therapeutic potential of AM 404 on ischaemia-induced neuronal injury was investigated in vivo and compared with that of the classical cannabinoid receptor type 1 (CB1) agonist, Δ9-tetraydrocannabinol (THC), using a model of transient global cerebral ischaemia in the gerbil. Experimental approach: The effects of AM 404 (0.015–2 mg kg−1) and THC (0.05–2 mg kg−1), given 5 min after ischaemia, were measured from 1 h to 7 days in terms of electroencephalographic (EEG) total spectral power, spontaneous motor activity, memory function, rectal temperature and hippocampal CA1 neuronal count. Key results: Over the dose range tested, AM 404 (2 mg kg−1) and THC (1 mg kg−1) completely reversed the ischaemia-induced behavioural, EEG and histological damage. Only THC (1 and 2 mg kg−1) induced a decrease of body temperature. Pretreatment with the selective CB1 receptor antagonist, AM 251 (1 mg kg−1) and the opioid antagonist, naloxone (2 mg kg−1) reversed the protective effect induced by both AM 404 and THC while the TRPV1 vanilloid antagonist, capsazepine (0.01 mg kg−1), was ineffective. Conclusions and implications: Our findings demonstrate that AM 404 and THC reduce neuronal damage caused by bilateral carotid occlusion in gerbils and that this protection is mediated through an interaction with CB1 and opioid receptors. Endocannabinoids might form the basis for the development of new neuroprotective drugs useful for the treatment of stroke and other neurodegenerative pathologies. British Journal of Pharmacology (2007) 152, 1301–1311; doi:10.1038/sj.bjp.0707514; published online 29 October 2007

Cl− channels activated by acidic extracellular pH have been observed in various mammalian cells but their molecular identity and mechanisms of regulation are unknown. The aim of this study was to analyse the acid-activated Cl− current (ICl(H)) by elucidating its functional properties and mechanisms of regulation in three different cell types: primary human bronchial epithelial (HBE) cells, neuroblastoma SK-N-MC cells and HEK-293 cells. We found that outward rectification, sensitivity to acidic pH (50% activation at pH5.15), permeability sequence (SCN−>I−>Br−>Cl−>gluconate), voltage dependence and sensitivity to blockers of ICl(H) were identical in all cells. These findings suggest a common molecular basis for ICl(H). We analysed the possible relationship of ICl(H) with members of ClC and TMEM16 protein families. By gene silencing, validated using RT-PCR, we found that ICl(H) is unrelated to ClC-3, ClC-7, TMEM16A, TMEM16D, TMEM16F, TMEM16H and TMEM16K. Analysis of possible mechanisms of regulation indicate that Ca2+, ATP and phosphorylation by PKA or PKC do not seem to be implicated in channel activation. Instead, the inhibition of ICl(H) by genistein and wortmannin suggest regulation by other kinases, possibly a tyrosine kinase and a phosphatidylinositol-3-kinase. Moreover, by using dynasore, the dynamin inhibitor, we found indications that exo/endocytosis is a mechanism responsible for ICl(H) regulation. Our results provide the first evidence about acid-activated Cl− channel regulation and, thus, could open the way for a better understanding of the channel function and for the molecular identification of the underlying protein.

Oxytocin (OT) and arginine-vasopressin (AVP) regulate social behavior in mammals. Zebrafish (Danio rerio) allows higher throughput and ease in studying human brain disorders.This study investigated in zebrafish the effect of non-mammalian homologs isotocin (IT) and vasotocin (AVT) in comparison with OT/AVP on social behavior and fear response to predator. The mechanism was studied using the most human selective OT and AVP receptor antagonists.Zebrafish were injected i.m. with increasing doses (0.001-40 ng/kg) of the neuropeptides. DesGly-NH(2)-d(CH(2))(5)-[D-Tyr(2),Thr(4)]OVT) for OT receptor, SR 49059 for V1a subtype receptor, and SSR-149415 for V1b subtype receptor were injected i.m. 10 min before each agonist.All the peptides increased social preference and reduced fear to predator response in a dose-dependent manner interpolated by symmetrical parabolas. AVT/AVP were more potent to elicit anxiolytic than social effect while IT and OT were equally potent. All the antagonists dose-dependently inhibited both the effects induced by the neuropeptides. The ratio between the ED50 obtained for blocking the OT-induced effects on social preference and fear response to predator was very high only for desglyDTTyrOVT (160). SR49059 showed the highest ratio in blocking AVP-induced effects (807). The less selective antagonist appeared to be SSR149415.For the first time, IT/AVT and OT/AVP were found to modulate in zebrafish, social behavior, unrelated to sex, and fear to predator response through at least two different receptors. Zebrafish is confirmed as a valid, reliable model to study deficit in social behavior characteristic of some psychiatric disorders.

Genistein is a naturally occurring plant-derived phytoestrogen, present in the human diet, known to possess some beneficial effects. The present study investigated the effect of genistein on neuroprotection evaluated through electroencephalographic and behavioural correlates in a model of global cerebral ischemia in gerbils. Over the dose range tested, genistein (3 and 10 mg/ kg), given 5 min after recirculation antagonized the ischemia-induced electroencephalographic total spectral power decrease 7 days after ischemia; fully prevented ischemia-induced hyperlocomotion evaluated 1 day after ischemia; reversed ischemia-induced memory impairment evaluated through both nest building behaviour and object recognition test; decreased malondialdehyde overproduction in the brain, evaluated 7 days after reperfusion; and fully promoted the survival of pyramidal cells in the CA1 hippocampal subfield. The selective antagonist for estrogen receptor–β (ERβ), 4-[2-phenyl-5,7-bis(trifluoromethyl) pyrazolo[1,5-a]pyrimidin-3-yl]phenol (PHTPP) given 30 min before carotid occlusion, fully prevented the neuroprotective effect of genistein at the dose of 3 mg/kg. These results demonstrate the neuroprotective effect of genistein through the activation of ERβ and provide further grounds for the growing interest concerning the true potential of phytoestrogens as compounds to beneficially affect brain injury without having the disadvantages of estrogens. Keywords:: ischemia, electroencephalography (EEG), phytoestrogen, CA1, estrogen receptor–β

Background Oxytocin (OT) has been suggested as a treatment to improve social behavior in autistic patients. Accordingly, the OT ( Oxt −/− ) and the OT receptor null mice ( Oxtr −/− ) display autistic-like deficits in social behavior, increased aggression, and reduced ultrasonic vocalization. Methods Oxtr −/− mice were characterized for general health, sociability, social novelty, cognitive flexibility, aggression, and seizure susceptibility. Because vasopressin (AVP) and OT cooperate in controlling social behavior, learning, and aggression, they were tested for possible rescue of the impaired behaviors. Primary hyppocampal cultures from Oxtr +/+ and Oxtr −/− mouse embryos were established to investigate the balance between gamma-aminobutyric acid (GABA) and glutamate synapses and the expression levels of OT and AVP (V1a) receptors were determined by autoradiography. Results Oxtr −/− mice display two additional, highly relevant, phenotypic characteristics: 1) a resistance to change in a learned pattern of behavior, comparable to restricted interests and repetitive behavior in autism, and 2) an increased susceptibility to seizures, a frequent and clinically relevant symptom of autism. We also show that intracerebral administration of both OT and AVP lowers aggression and fully reverts social and learning defects by acting on V1a receptors and that seizure susceptibility is antagonized by peripherally administered OT. Finally, we detect a decreased ratio of GABA–ergic versus total presynapses in hippocampal neurons of Oxtr −/− mice. Conclusions Autistic-like symptoms are rescued on administration of AVP and OT to young Oxtr −/− adult animals. The Oxtr −/− mouse is thus instrumental to investigate the neurochemical and synaptic abnormalities underlying autistic-like disturbances and to test new strategies of pharmacologic intervention.

Background and purpose: Drugs targeting brain κ-opioid receptors produce profound alterations in mood. In the present study we investigated the possible anxiolytic- and antidepressant-like effects of the κ-opioid receptor agonist salvinorin A, the main active ingredient of Salvia divinorum, in rats and mice. Experimental approach: Experiments were performed on male Sprague-Dawley rats or male Albino Swiss mice. The anxiolytic-like effects were tested by using the elevated plus maze, in rats. The antidepressant-like effect was estimated through the forced swim (rats) and the tail suspension (mice) test. κ-Opioid receptor involvement was investigated pretreating animals with the κ-opioid receptor antagonist, nor-binaltorphimine (1 or 10 mg·kg−1), while direct or indirect activity at CB1 cannabinoid receptors was evaluated with the CB1 cannabinoid receptor antagonist, N-(piperidin-1-yl) -5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251, 0.5 or 3 mg·kg−1), binding to striatal membranes of naive rats and assay of fatty acid amide hydrolase in prefrontal cortex, hippocampus and amygdala. Key results: Salvinorin A, given s.c. (0.001–1000 µg·kg−1), exhibited both anxiolytic- and antidepressant-like effects that were prevented by nor-binaltorphimine or AM251 (0.5 or 3 mg·kg−1). Salvinorin A reduced fatty acid amide hydrolase activity in amygdala but had very weak affinity for cannabinoid CB1 receptors. Conclusions and implications: The anxiolytic- and antidepressant-like effects of Salvinorin A are mediated by both κ-opioid and endocannabinoid systems and may partly explain the subjective symptoms reported by recreational users of S. divinorum.

Few and often contradictory reports exist on the long-term neurobiological consequences of cannabinoid consumption in adolescents. The endocannabinoid system plays an important role during the different stages of brain development as cannabinoids influence the release and action of different neurotransmitters and promote neurogenesis. This study tested whether long-lasting interference by cannabinoids with the developing endogenous cannabinoid system during adolescence caused persistent behavioral alterations in adult rats. Adolescent female and male rats were treated with increasing doses of Delta(9)-tetrahydrocannabinol (THC) for 11 days (postnatal day (PND) 35-45) and left undisturbed until adulthood (PND 75) when behavioral and biochemical assays were carried out. CB1 receptor level and CB1/G-protein coupling were significantly reduced by THC exposure in the amygdala (Amyg), ventral tegmental area (VTA) and nucleus accumbens (NAc) of female rats, whereas male rats had significant alterations only in the amygdala and hippocampal formation. Neither female nor male rats showed any changes in anxiety responses (elevated plus maze and open-field tests) but female rats presented significant 'behavioral despair' (forced swim test) paralleled by anhedonia (sucrose preference). In contrast, male rats showed no behavioral despair but did present anhedonia. This different behavioral picture was supported by biochemical parameters of depression, namely CREB alteration. Only female rats had low CREB activity in the hippocampal formation and prefrontal cortex and high activity in the NAc paralleled by increases in dynorphin expression. These results suggest that heavy cannabis consumption in adolescence may induce subtle alterations in the emotional circuit in female rats, ending in depressive-like behavior, whereas male rats show altered sensitivity to rewarding stimuli.