Communication and social interaction in the cannabinoid-type 1 receptor null mouse: Implications for autism spectrum disorder.

Clinical and preclinical findings have suggested a role of the endocannabinoid system (ECS) in the etiopathology of autism spectrum disorder (ASD). Previous mouse studies have investigated the role of ECS in several behavioral domains; however, none of them has performed an extensive assessment of social and communication behaviors, that is, the main core features of ASD. This study employed a mouse line lacking the primary endocannabinoid receptor (CB1r) and characterized ultrasonic communication and social interaction in CB1-/- , CB1+/- , and CB1+/+ males and females. Quantitative and qualitative alterations in ultrasonic vocalizations (USVs) were observed in CB1 null mice both during early development (i.e., between postnatal days 4 and 10), and at adulthood (i.e., at 3 months of age). Adult mutants also showed marked deficits in social interest in the three-chamber test and social investigation in the direct social interaction test. These behavioral alterations were mostly observed in both sexes and appeared more marked in CB1-/- than CB1+/- mutant mice. Importantly, the adult USV alterations could not be attributed to differences in anxiety or sensorimotor abilities, as assessed by the elevated plus maze and auditory startle tests. Our findings demonstrate the role of CB1r in social communication and behavior, supporting the use of the CB1 full knockout mouse in preclinical research on these ASD-relevant core domains. LAY SUMMARY: The endocannabinoid system (ECS) is important for brain development and neural function and is therefore likely to be involved in neurodevelopmental disorders such as Autism Spectrum Disorder (ASD). Here we investigated changes in social behavior and communication, which are core features of ASD, in male and female mice lacking the chief receptor of this system. Our results show that loss of this receptor results in several changes in social behavior and communication both during early development and in adulthood, thus supporting the role of the ECS in these ASD-core behavioral domains.

N,N-dimethyltryptamine compound found in the hallucinogenic tea ayahuasca, regulates adult neurogenesis in vitro and in vivo.

N,N-dimethyltryptamine (DMT) is a component of the ayahuasca brew traditionally used for ritual and therapeutic purposes across several South American countries. Here, we have examined, in vitro and vivo, the potential neurogenic effect of DMT. Our results demonstrate that DMT administration activates the main adult neurogenic niche, the subgranular zone of the dentate gyrus of the hippocampus, promoting newly generated neurons in the granular zone. Moreover, these mice performed better, compared to control non-treated animals, in memory tests, which suggest a functional relevance for the DMT-induced new production of neurons in the hippocampus. Interestingly, the neurogenic effect of DMT appears to involve signaling via sigma-1 receptor (S1R) activation since S1R antagonist blocked the neurogenic effect. Taken together, our results demonstrate that DMT treatment activates the subgranular neurogenic niche regulating the proliferation of neural stem cells, the migration of neuroblasts, and promoting the generation of new neurons in the hippocampus, therefore enhancing adult neurogenesis and improving spatial learning and memory tasks.

Associations between experimental substance use, faah-gene variations, impulsivity and sensation seeking / Asociaciones entre el uso experimental de sustancias, variaciones del gen FAAH, impulsividad y búsqueda de sensaciones

Background: Experimental substance use among young people is related to individual factors including personality traits such as impulsivity and sensation seeking, and genetic variations such as single nucleotide polymorphisms (SNPs) in the fatty acid amide hydrolase (FAAH) gene. The objective of this study is to analyze the relationship between these three sets of variables. Methods: Volunteer undergraduate students (N = 861, 76% female, M = 20.7 years) completed an ad hoc questionnaire on variables related to their consumption of alcohol, tobacco, cannabis, synthetic drugs and cocaine. In addition, 591 of them completed the Barratt Impulsiveness Scale-11 (BIS-11) and the Sensation Seeking Scale-V (SSS-V). All participants were genotyped in FAAH C385A SNP and its proxy variant rs12075550. Results: Consistent with previous data, both impulsivity and sensation seeking were associated with most of the variables related to experimental substance use. In addition, we found the first evidence of an association between the rs12075550 SNP and some of these consumption phenotypes. However, no significant association was found between either of the two SNPs and impulsivity or sensation seeking. Conclusions: The results highlight the importance of considering both personality and genetic differences, together with contextual factors, in the analysis of substance use

Antecedentes: el uso experimental de sustancias en los jóvenes está relacionada con factores individuales que incluyen rasgos de personalidad, como impulsividad o búsqueda de sensaciones, y variaciones genéticas, como polimorfismos de un solo nucleótido (SNPs) del gen amida hidrolasa de ácidos grasos (FAAH). El objetivo de este estudio es analizar la relación entre estos tres conjuntos de variables. Método: estudiantes universitarios voluntarios (N = 861, 76% mujeres, M = 20,7 años) rellenaron un cuestionario ad hoc de variables relacionadas con el consumo de alcohol, tabaco, cannabis, drogas sintéticas y cocaína. Además, 591 de ellos rellenaron las escalas BIS-11 y SSS-V. Se genotipó a todos ellos en SNP FAAH C385A y su variante proxy rs12075550. Resultados: como se esperaba, la impulsividad y la búsqueda de sensaciones estuvieron asociadas con la mayor parte de las variables relativas al uso experimental de sustancias. Además, encontramos por primera vez evidencia de una asociación entre rs12075550 y algunos de estos fenotipos de consumo. Sin embargo, no encontramos asociaciones significativas entre SNPs e impulsividad o búsqueda de sensaciones. Conclusiones: los resultados resaltan la importancia de tener en cuenta las diferencias genéticas y las de personalidad, junto con los factores contextuales, al analizar el uso de sustancias

Associations between experimental substance use, FAAH-gene variations, impulsivity and sensation seeking.

BACKGROUND: Experimental substance use among young people is related to individual factors including personality traits such as impulsivity and sensation seeking, and genetic variations such as single nucleotide polymorphisms (SNPs) in the fatty acid amide hydrolase (FAAH) gene. The objective of this study is to analyze the relationship between these three sets of variables. METHODS: Volunteer undergraduate students (N = 861, 76% female, M = 20.7 years) completed an ad hoc questionnaire on variables related to their consumption of alcohol, tobacco, cannabis, synthetic drugs and cocaine. In addition, 591 of them completed the Barratt Impulsiveness Scale-11 (BIS-11) and the Sensation Seeking Scale-V (SSS-V). All participants were genotyped in FAAH C385A SNP and its proxy variant rs12075550. RESULTS: Consistent with previous data, both impulsivity and sensation seeking were associated with most of the variables related to experimental substance use. In addition, we found the first evidence of an association between the rs12075550 SNP and some of these consumption phenotypes. However, no significant association was found between either of the two SNPs and impulsivity or sensation seeking. CONCLUSIONS: The results highlight the importance of considering both personality and genetic differences, together with contextual factors, in the analysis of substance use.

Phosphodiesterase7 Inhibition Activates Adult Neurogenesis in Hippocampus and Subventricular Zone In Vitro and In Vivo.

The phosphodiesterase 7 (PDE7) enzyme is one of the enzymes responsible for controlling intracellular levels of cyclic adenosine 3',5'-monophosphate in the immune and central nervous system. We have previously shown that inhibitors of this enzyme are potent neuroprotective and anti-inflammatory agents. In addition, we also demonstrated that PDE7 inhibition induces endogenous neuroregenerative processes toward a dopaminergic phenotype. Here, we show that PDE7 inhibition controls stem cell expansion in the subgranular zone of the dentate gyrus of the hippocampus (SGZ) and the subventricular zone (SVZ) in the adult rat brain. Neurospheres cultures obtained from SGZ and SVZ of adult rats treated with PDE7 inhibitors presented an increased proliferation and neuronal differentiation compared to control cultures. PDE7 inhibitors treatment of neurospheres cultures also resulted in an increase of the levels of phosphorylated cAMP response element binding protein, suggesting that their effects were indeed mediated through the activation of the cAMP/PKA signaling pathway. In addition, adult rats orally treated with S14, a specific inhibitor of PDE7, presented elevated numbers of proliferating progenitor cells, and migrating precursors in the SGZ and the SVZ. Moreover, long-term treatment with this PDE7 inhibitor shows a significant increase in newly generated neurons in the olfactory bulb and the hippocampus. Also a better performance in memory tests was observed in S14 treated rats, suggesting a functional relevance for the S14-induced increase in SGZ neurogenesis. Taken together, our results indicate for the first time that inhibition of PDE7 directly regulates proliferation, migration and differentiation of neural stem cells, improving spatial learning and memory tasks. Stem Cells 2017;35:458-472.

Fatty acid amide hydrolase inhibition for the symptomatic relief of Parkinson's disease.

Elements of the endocannabinoid system are strongly expressed in the basal ganglia where they suffer profound rearrangements after dopamine depletion. Modulation of the levels of the endocannabinoid 2-arachidonoyl-glycerol by inhibiting monoacylglycerol lipase alters glial phenotypes and provides neuroprotection in a mouse model of Parkinson's disease. In this study, we assessed whether inhibiting fatty acid amide hydrolase could also provide beneficial effects on the time course of this disease. The fatty acid amide hydrolase inhibitor, URB597, was administered chronically to mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and probenecid (MPTPp) over 5weeks. URB597 (1mg/kg) prevented MPTPp induced motor impairment but it did not preserve the dopamine levels in the nigrostriatal pathway or regulate glial cell activation. The symptomatic relief of URB597 was confirmed in haloperidol-induced catalepsy assays, where its anti-cataleptic effects were both blocked by antagonists of the two cannabinoid receptors (CB1 and CB2), and abolished in animals deficient in these receptors. Other fatty acid amide hydrolase inhibitors, JNJ1661010 and TCF2, also had anti-cataleptic properties. Together, these results demonstrate an effect of fatty acid amide hydrolase inhibition on the motor symptoms of Parkinson's disease in two distinct experimental models that is mediated by cannabinoid receptors.