New Results: Sex differences in the behavioral and synaptic consequences of a single exposure to cannabinoid at puberty and adulthood
Heavy cannabis consumption among adolescents is associated with significant and lasting neurobiological, psychological and health consequences that depend on the age of first use. Chronic exposure to cannabinoid (CB) agonists during adolescence alters social behavior and prefrontal cortex (PFC) activity in adult rats. However, sex differences on social behavior as well as PFC synaptic plasticity after acute CB activation remain poorly explored. Here, we determined the consequences of a single CB activation differently affects PFC in males and females by assessing social behavior and PFC neuronal and synaptic functions in rats during pubertal or adulthood periods, 24h after a single in-vivo cannabinoid exposure (SCE). During puberty, SCE reduced play behavior in females but not males. In contrast, SCE impaired sociability in both sexes at adulthood. General exploration and memory recognition remained normal at both ages and both sexes. At the synaptic level, SCE ablated endocannabinoid-mediated long-term depression (eCB-LTD) in the PFC of females of both ages and heightened excitability of PFC pyramidal neurons at adulthood, while males were spared. In contrast, SCE was associated to impaired long-term potentiation in adult males. Together, the data indicate behavioral and synaptic sex differences in response to a single in-vivo exposure to cannabinoid at puberty and adulthood.
New Results: Maternal cannabinoid exposure during lactation alters the developmental trajectory of prefrontal cortex GABA-currents in offspring
Cannabis is the most widely used illicit drug in the world, and its usage is increasing with its widespread legalization. Use of the drug by mothers during lactation may transfer active cannabinoids to the developing offspring, altering postnatal neurodevelopment during this critical period. During early life, GABA undergoes a functional switch from an excitatory to an inhibitory neurotransmitter due to reciprocal changes in expression of the K+/Cl- co-transporters KCC2 and NKCC1. Here, we characterize the functional GABA switch in the prefrontal cortex of both male and female rats. We show that treating rat dams with Δ-THC or a synthetic cannabinoid during early lactation (PND01-10) retards KCC2 expression and delays the GABA switch in pups of both sexes via a CB1R-dependent mechanism. Our results indicate that the developmental trajectory of GABA in PFC neurons is significantly altered by perinatal exposure to cannabinoids through lactation during the early perinatal period.
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Join the Lab
If you are interested in being considered for a postdoctoral position, send an email to email@example.com / firstname.lastname@example.org
Required qualifications for these positions are (1) at least one first-authored paper in areas related to systems, cellular, or computational neuroscience; (2) research experience in one of these fields: electrophysiology, imaging, MATLAB (or equivalent) programming or computational statistics. Preference will be given to applicants interested in research questions related to mental health.
A postdoctoral position is available in the CannaLab/Adolescence and developmental vulnerability to neuropsychiatric diseases team at INMED, Marseille.
The CannaLab associates our laboratory and the laboratory of Pr. Ken Mackie (Gill Center For Biomolecular Medicine, Indiana University, Bloomington USA). Our common project aims at shedding new light on the structural, molecular and functional synaptic substrates of the sex-specific effects of adolescent cannabis use on behavior. The project will focus on the consequences of adolescent exposure to cannabis on mesocorticolimbic networks. The project will involve a multidisciplinary approach performed in animal models combining electrophysiological recordings and calcium imaging in vivo and in vitro.
This project is funded by the NIH-RO1 “Sex-specific critical periods of the effects of mesocorticolimbic system”. Marseille is France second largest city, a 3000-year-old port in the Mediterranean. Successful candidates will have a Ph.D. in Neuroscience and strong expertise in neuronal network, electrophysiology and imaging in rodent models of neuropsychiatric diseases. Salary will follow INSERM guidelines. Applicants should send their curriculum vitae, a list of publications, and a letter describing their interests and proposed research by email to Olivier Manzoni: email@example.com
New Publication: Sex specific endophenotypes of in-utero cannabinoid exposure
Cannabinoids can cross the placenta, thus may interfere with fetal endocannabinoid signaling during neurodevelopment, causing long-lasting deficits. Despite increasing cannabis consumption during pregnancy, the protracted consequences of prenatal cannabinoid exposure (PCE) remain incompletely understood. Here we report sex-specific differences in behavioral and neuronal deficits in the adult progeny of rat dams exposed to low doses of cannabinoids during gestation. In males, PCE reduced social interaction, ablated endocannabinoid long-term depression (LTD) and heightened excitability of prefrontal cortex pyramidal neurons, while females were spared. Group 1 mGluR and endocannabinoid signaling regulate emotional behavior and synaptic plasticity. Notably, sex-differences following PCE included levels of mGluR1/5 and TRPV1R mRNA. Finally, positive allosteric modulation of mGlu5 and enhancement of anandamide levels restored LTD and social interaction in PCE adult males. Together, these results highlight marked sexual differences in the effects of PCE and introduce strategies for reversing detrimental effects of PCE.
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Multivariate synaptic and behavioral profiling reveals new developmental endophenotypes in the prefrontal cortex
The postnatal maturation of the prefrontal cortex (PFC) represents a period of increased vulnerability to risk factors and emergence of neuropsychiatric disorders. To disambiguate the pathophysiological mechanisms contributing to these disorders, we revisited the endophenotype approach from a developmental viewpoint. The extracellular matrix protein reelin which contributes to cellular and network plasticity, is a risk factor for several psychiatric diseases. We mapped the aggregate effect of the RELN risk allele on postnatal development of PFC functions by cross-sectional synaptic and behavioral analysis of reelin-haploinsufficient mice. Multivariate analysis of bootstrapped datasets revealed subgroups of phenotypic traits specific to each maturational epoch. The preeminence of synaptic AMPA/NMDA receptor content to pre-weaning and juvenile endophenotypes shifts to long-term potentiation and memory renewal during adolescence followed by NMDA-GluN2B synaptic content in adulthood. Strikingly, multivariate analysis shows that pharmacological rehabilitation of reelin haploinsufficient dysfunctions is mediated through induction of new endophenotypes rather than reversion to wild-type traits. By delineating previously unknown developmental endophenotypic sequences, we conceived a promising general strategy to disambiguate the molecular underpinnings of complex psychiatric disorders and for the rational design of pharmacotherapies in these disorders.
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Molecular Psychiatry: Reelin a new mechanism for how eating high-fat foods in excess during adolescence alters executive functions
Chances are that children who eat excessive amounts of fatty foods will not only become obese, but will develop cognitive and psychiatric problems when they are older, a study in mice suggests. This is because, according to a recent study, diets rich in fat deplete the levels of a key protein known to help synapses in the brain to work properly. In turn, this leads to a dip in several forms of cognitive functions, such as behavioral flexibility and memory.
From ScienceDaily, Read the rest here.
And get the full paper here.
Hypervulnerability of the adolescent prefrontal cortex to nutritional stress via reelin deficiency. M A Labouesse, O Lassalle, J Richetto, J Iafrati, U Weber-Stadlbauer, T Notter, T Gschwind, L Pujadas, E Soriano, A C Reichelt, C Labouesse, W Langhans, P Chavis# & U Meyer#; shared seniority ; Molecular Psychiatry volume 22, pages 961–971 (2017)
Our general aim is to understand how meso-corticolimbic (MCL) microcircuits are shaped throughout early life critical periods especially adolescence, to give rise to harmonious emotional behaviors and cognitive functions in adulthood. Specifically, we want to understand how environmental and genetic insults modeling neuropsychiatric diseases transform the architecture and the functionality of synaptic networks and reduce the behavioral working range.
Our previous work fueled the concept that structural and functional damages during early life periods including adolescence are causal in disease-linked behavioral deficits. Our core hypothesis is that adolescence delineates a period of maximal vulnerability and consequently is a critical determinant of how environments and genes shape neuronal network functions into adulthood (Bara et al. 2018; Labouesse et. al. 2017; Manduca et al. 2017; Bouamrane et al. 2017; Iafrati et al. 2016; Iafrati et al. 2014).
Our research project will allow disambiguating complex phenotypes into new developmental endophenotypes and the design of innovative therapeutic strategies.
Our project is organized in three objectives:
First, we systematically audit structural and functional properties to determine how development shapes MCL microcircuits.
Second, we use a strategy that we recently conceived, based on multivariate analysis of bootstrapped datasets (Iafrati et al. 2016) to consider the multidimensional nature of the data and evaluate the interrelationship between structural, functional and behavioral parameters.
Third, we use optogenetic stimulation and pharmacological modulation of specific neuronal microcircuits to recreate/compensate/reactivate adapted behavioral in diseased rodents.
Our multidisciplinary approach combines, electrophysiology, ablation by toxin receptor cell targeting of selected neuronal population, in vitro and in vivo calcium imaging, quantitative tridimensional neuroanatomy, optogenetics and the analysis of naturalistic behaviors across the emotional and cognitive domains.
International Associated Laboratory INSERM - Indiana University
The International Associated Laboratory INSERM-Indiana University was created by INSERM. CannaLab associates our lab and the laboratory of Pr. Ken Mackie, Director of the Gill Center For Biomolecular Medicine (Indiana University, Bloomington USA). Our project aims at shedding new light on the structural, molecular and functional synaptic substrates of the sex-specific effects of adolescent cannabis use on behavior.
Synapse; synaptic plasticity, Extracellular matrix; Accumbens, Prefrontal cortex; Reelin; Endocannabinoid, mGluR, NMDAR; Pharmacotherapy; Autism, Fragile X, Nutrition, Adolescence.
- Barbara Bardoni (Autism / CNRS UMR 7275, IPMC, Nice).
- Sophie Layé (Nutrition & Integrative Neurobiology / INRA UMR 1286, Bordeaux).
- Urs Meyer (University of Zürich, Switzerland)
- Ken Mackie (Indiana University, Bloomington USA).
-Rainer Spanagel (CB1R and mGluRs in the mesolimbic pathway / Mainz University, Germany)
- NIH (co-P.I. O. MANZONI & K. MACKIE)
- FRC (De CHEVIGNY, P. CHAVIS)
- FRM (P.I. O. MANZONI)
Google Scholar P. Chavis