Biology subjects

Lujan, M. A.

Publications and source records attributed to Lujan, M. A..

5 recordsLinked to original sources

bioRxiv2025

Concurrent maternal stress and THC exposure during pregnancy alters adolescent behavioral outcomes and corticolimbic molecular programs

Cannabis use during pregnancy is increasing, often to alleviate stress and anxiety, yet the long-term effect of prenatal cannabis exposure alone or in combination with psychosocial stress on offspring neurodevelopment or maternal behaviors remains unclear. Here, we developed a translational rodent model combining prenatal {Delta}-tetrahydrocannabinol (THC) exposure with chronic psychosocial stress using the maternal witness defeat stress (MWDS) paradigm. Pregnant C57BL/6 mice were exposed to MWDS from gestational day (GD) 3-12 and received daily subcutaneous THC (2 mg/kg) or vehicle until birth. All exposure groups showed impaired maternal behavior, with negative postnatal outcomes and caregiving, with additive effects observed in the combined exposure group. In adolescence, male and female offspring exhibited exposure-specific behavioral alterations. Prenatal stress and combined exposures led to increased anxiety-like behavior and reduced motivated behavior in both sexes, while THC alone primarily impacted female self-care and social behavior. Transcriptomic profiling of the prefrontal cortex (PFC) and nucleus accumbens (NAc) of adolescent offspring revealed sex- and region-specific gene expression changes across all exposure groups. Prenatal THC-, stress-, and combined exposures each altered distinct molecular pathways related to mitochondrial function, synaptic organization, and glial signaling. Comparative analysis with a perinatal fentanyl model revealed shared transcriptional substrates involved in synaptic signaling and circadian regulation. These findings indicate that THC and stress independently and additively impair maternal behaviors with lasting neurodevelopment signatures in offspring.

neuroscience↗

bioRxiv2024

Dynamic Accumbal Overrepresentation of Reward Cues in Food- and Opioid-Seeking Rats after Prenatal THC Exposure

The increasing prevalence of cannabis use during pregnancy has raised significant medical concerns, primarily related to the presence of {Delta}9-tetrahydrocannabinol (THC), which readily crosses the placenta and impacts fetal brain development. Previous research has identified midbrain dopaminergic neuronal alterations related to maternal THC consumption. However, the enduring consequences that prenatal cannabis exposure (PCE) has on striatum-based processing during voluntary reward pursuit have not been specifically determined. Here, we characterize PCE rats during food (palatable pellets) or opioid (remifentanyl)-maintained reward seeking. We find that the supra motivational phenotype of PCE rats is independent of value-based processing and is instead related to augmented reinforcing efficiency of opioid rewards. Our findings reveal that in utero THC exposure leads to increased cue-evoked dopamine release responses and an overrepresentation of cue-aligned, effort-driven striatal patterns of encoding. Recapitulating findings in humans, drug-related neurobiological adaptations of PCE were more pronounced in males, who similarly showed increased vulnerability for relapse. Collectively, these findings indicate that prenatal THC exposure in male rats engenders a pronounced neurodevelopmental susceptibility to addiction-like disorders later in life.

neuroscience↗

bioRxiv2022

A multivariate regressor of patterned dopamine release predicts relapse to cocaine

Drug addiction is characterized by a sustained vulnerability to relapse even after long periods of abstinence. A deeper understanding of the brain systems underlying this state could inform therapeutic strategies with novel prognostic biomarkers aimed at preventing renewed drug seeking. Most drugs of abuse, in particular psychostimulants such as cocaine, lead to long-lasting mesolimbic dopamine system adaptations, that ultimately facilitate drug seeking following exposure to drug-paired cues. This "dopaminergic hypothesis" of relapse has been previously addressed, but technical limitations in measuring in vivo dopamine release have precluded the assessment of its sufficiency without introducing pharmacological, electrical, or optogenetic confounds. Using a dopamine receptor-based fluorescent sensor in freely moving mice, we show that long-lasting dopamine recordings in the nucleus accumbens (NAc), throughout the animals entire history of cocaine self-administration, are strong predictors of relapse as well as the time it takes an animal to extinguish its drug seeking behavior. Moreover, we reveal previously unseen sex-specific trajectories of cocaine-related phasic dopamine responses from acquisition to relapse. We show that males exhibit higher-amplitude phasic dopamine responses, a trait accompanied by a greater resistance to extinguish their cocaine seeking, compared to females. Furthermore, we show that a semi-parametric model of the transition to extinction - using only multivariate patterns of dopamine release and sex as covariates - faithfully recapitulates male-specific vulnerability to persistent cocaine seeking. In conclusion, we present a predictive model of reinstatement behavior that uses information exclusively conveyed by NAc phasic dopamine responses, thus confirming, and actuating the sufficiency of the dopaminergic hypothesis of relapse.

neuroscience↗

bioRxiv2020

Cannabidiol effects on cocaine-seeking behaviour and incubation of craving in mice.

Background and PurposeTo remain abstinent represents one of the major challenges for the treatment of cocaine use disorder. Cocaine seeking elicited by drug-associated cues progressively intensifies during abstinence in a process termed incubation of craving, representing an aggravating factor for relapse. Cannabidiol is a phytocannabinoid that exerts protecting effects upon cocaine-seeking behaviour, although its effects on cocaine-craving incubation have never been elucidated. Experimental ApproachWe developed a mouse model of behavioural economic analysis of demand curves and incubation of cue-induced cocaine craving. Changes in the protein expression of AMPAR subunits and ERK1/2 phosphorylation were analysed. We also assessed the effects of cannabidiol (20 mg{middle dot}kg-1) administered either during acquisition of cocaine self-administration or abstinence. Key ResultsMice efficiently performed the demand task and incubation of cocaine craving. Besides, changes in GluA1 and GluA2 protein levels were found along the abstinence in prelimbic cortex, ventral striatum and amygdala, as well as a decrease in ERK1/2 phosphorylation in ventral striatum. Cannabidiol reduced ongoing cocaine intake when administered during the acquisition phase of the self-administration, but failed to alter the subsequent demand task performance and incubation of cocaine craving. No effects were found when cannabidiol was administered during the abstinence period. Conclusion and ImplicationsWe provide here a novel model of behavioural economic analysis of demand curves and cue-induced incubation of cocaine-seeking behaviour for mice. Moreover, we show that cannabidiol exerts differential effects on the current model depending on the self-administration phase in which it was administered. What is already knownO_LIBehavioural economics and incubation of cocaine craving are well-stablished paradigms to evaluate cocaine seeking in rats. C_LIO_LICBD reduces cocaine-seeking and cocaine-taking behaviours. C_LI What this study addsO_LIA mouse model of behavioural economic analysis of demand curves and incubation of cue-induced cocaine craving. C_LIO_LICBD reduces cocaine self-administration and has no effect over demand task and cocaine-craving incubation. C_LI Clinical significanceO_LIA new behavioural model for studying cocaine addiction in mice. C_LIO_LICBD exerts differential effects depending on when it was administered in the addictive process. C_LI TO_SCPLOWABLESC_SCPLOWO_SCPCAP C_SCPCAPO_SCPLOWOFC_SCPLOW LO_SCPLOWINKSC_SCPLOW O_TBL View this table: org.highwire.dtl.DTLVardef@654e3aorg.highwire.dtl.DTLVardef@f2d37aorg.highwire.dtl.DTLVardef@1a0396org.highwire.dtl.DTLVardef@1e19d1dorg.highwire.dtl.DTLVardef@1121b7b_HPS_FORMAT_FIGEXP M_TBL C_TBL

neuroscience↗

bioRxiv2020

The effects of cannabidiol on cue- and stress-induced reinstatement of cocaine seeking behavior in mice are reverted by the CB1 receptor antagonist AM4113.

Cocaine addiction is a brain disorder characterized by the consumption of the drug despite harmful consequences, the loss of control over drug intake and increased risk of relapse. Albeit prolonged research efforts, there is no available medication approved for the treatment of cocaine addiction. In the last decade, cannabinoid-based compounds have drawn increased interest for its potential therapeutic applications in various psychiatric conditions. Cannabidiol, a non-psychotomimetic constituent of the C. sativa plant, shows promising results in rodent models of anxiety, schizophrenia, depression and drug addiction. However, the specific effects and mechanisms of action of cannabidiol in a rodent model of extinction-based abstinence and drug seeking relapse remain unclear. Here, we administered cannabidiol (20 mg/kg) to male CD-1 mice trained to self-administer cocaine (0.75 mg/kg/inf) during extinction training (8-12 days). Then, we evaluated the reinstatement of cocaine seeking induced by cues, stress and drug priming. To ascertain the participation of CB1 receptors in these behavioral responses, we systemically administered the neutral cannabinoid antagonist AM4113 (5 mg/kg) before each reinstatement session. The results document that cannabidiol (20 mg/kg) does not modulate extinction training but attenuates extinction burst responding after one cannabidiol injection. Furthermore, cannabidiol specifically blocked the reinstatement of cocaine seeking triggered by a cue presentation, an effect prevented by AM4113 (5 mg/kg). Unexpectedly, cannabidiol facilitated stress-induced reinstatement of cocaine seeking behavior, also by a CB1-dependent mechanism. Finally, cannabidiol did not affect cocaine-primed (10 mg/kg) precipitation of cocaine seeking. Our results reveal a series of complex changes induced by cannabidiol treatment with opposite implications for the reinstatement of cocaine seeking behavior that may limit therapeutic opportunities. The activity of CB1 receptors seems to play a crucial role in the expression of cannabidiol-induced neuroplasticity underlying both the desirable and undesirable reinstatement effects here detailed.

neuroscience↗