Biology subjects

Alegre-Zurano, L.

Publications and source records attributed to Alegre-Zurano, L..

6 recordsLinked to original sources

bioRxiv2024

Lack of rhythmicity in Bmal1 deficient mice impairs motivation towards natural stimuli.

Maintaining appropriate circadian rhythmicity is essential for coordinating the activity of biological functions in mammalian organisms. A variety of physiological and behavioral changes have been associated with disturbances of this complex clock mechanism. In the present study, we delve into the consequences of circadian arrhythmia using the Bmal1-knockout (KO) mouse line aiming to explore potential behavioral and motivational implications. We were able to identify the intricate activity patterns that define circadian disturbance in Bmal1-KO mice by utilizing a new analysis model based on entropy divergence. Alterations in locomotor activity were accompanied by disruptions of circadian expression patterns in various clock genes as revealed by gene expression analysis. Additionally, we found a dysregulated gene expression profile in Bmal1-KO mice regarding genes related to circadian control in various brain nuclei. Specifically, the ventral striatum exhibited a dysregulation in the expression levels of genes modulating reward and motivation. Further investigation revealed that BMAL1 deficient mice showed a sustained rise in motivation and seeking behavior for food and water reinforcers in the self-administration paradigm, independently of the caloric content of the reward. Together, our data reveal that disruptions in circadian rhythmicity, induced by alterations in the molecular clock, also impact the gene expression regulating the reward system. This, in turn, can lead to altered seeking behavior and motivation for natural rewards. In summary, the present study contributes to our understanding of how reward processing is under the regulation of circadian clock machinery.

neuroscience↗

bioRxiv2023

The FAAH inhibitor URB597 reduces cocaine seeking during conditioned punishment and withdrawal

The endocannabinoid system is prominently implicated in the control of cocaine reinforcement due to its relevant role in synaptic plasticity and neurotransmitter modulation in the mesocorticolimbic system. The inhibition of fatty acid amide hydrolase (FAAH), and the resulting increase in anandamide and other N-acylethanolamines, represents a promising strategy for reducing drug seeking. In the present study, we aimed to assess the effects of the FAAH inhibitor URB597 (1 mg/kg) on crucial features of cocaine addictive-like behaviour in mice. Therefore, we tested the effects of URB597 on acquisition of cocaine (0.6 mg/kg/inf) self-administration, compulsive-like cocaine intake and cue-induced drug-seeking behaviour during withdrawal. URB597 reduced cocaine intake under conditioned punishment while having no impact on acquisition. This result was associated to increased cannabinoid receptor 1 gene expression in the ventral striatum and medium spiny neurons activation in the nucleus accumbens shell. Moreover, URB597 reduced cue-induced drug-seeking behaviour during prolonged abstinence and prevented the withdrawal-induced increase in FAAH gene expression in the ventral striatum. In this case, URB597 decreased activation of medium spiny neurons in the nucleus accumbens core. Our findings evidence the prominent role of endocannabinoids in the development of cocaine addictive-like behaviours and support the potential of FAAH inhibition as a therapeutical target for the treatment of cocaine addiction.

neuroscience↗

bioRxiv2022

Bmal1-knockout mice exhibit reduced cocaine-seeking behaviour and cognitive impairments

Brain and Muscle Arnt-like Protein 1 (BMAL1) is an essential component of the molecular clock underlying circadian rhythmicity. Recently, its function has also been associated with alterations in mood, and reward processing. We investigated the behavioural and neurobiological impact of Bmal1 gene deletion in mice, as well as how these alterations affect rewarding effects of cocaine. Additionally, key clock genes and components of the dopamine system were assessed in several brain areas. Our results evidence behavioural alterations in Bmal1-KO mice including changes in locomotor activity with impaired habituation to environments as well as short term memory and social recognition impairments. In addition, Bmal1-KO mice experienced reduced cocaine-induced sensitization and rewarding effects of cocaine as well as reduced cocaine-seeking behaviour. Furthermore, Bmal1 deletion influenced the expression of other clock-related genes in the mPFC and striatum as well as alterations in the expression of dopaminergic elements. Overall, the present article offers a novel and extensive characterization of Bmal1-KO animals. We suggest that reduced cocaines rewarding effects in these mutant mice might be related to Bmal1 role as an expression regulator of MAO and TH, two essential enzymes involved in dopamine metabolism.

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

BEHAVIOURAL AND MOLECULAR EFFECTS OF CANNABIDIOLIC ACID IN MICE

ABSTRACTAims Cannabidiolic acid (CBDA) is one of the most abundant phytocannabinoid acids in the Cannabis Sativa plant. It has been shown it is able to exert some therapeutic effects such as antiemetic, anti-inflammatory, anxiolytic or antidepressant, although some of them remain under debate. In the present study we aim to assess the potential effects of CBDA on different behaviours and on the modulation of neuroinflammatory markers in the prefrontal cortex (PFC).Main methods the effects of acute and/or chronic CBDA (0.001-1 mg/kg i.p.) treatment were evaluated on cognitive, emotional, motivational and nociceptive behaviours in male CD1 mice. For this, Y-maze and elevated plus maze paradigms, spontaneous locomotor activity, social interaction, hot-plate, formalin and tail suspension tests were used. We also studied the effects of CBDA on the rewarding responses of cocaine in the conditioned place preference (CPP) paradigm. PFC was dissected after acute and chronic CBDA treatments to evaluate inflammatory markers.Key findings acute CBDA treatment induced antinociceptive responses in the hot-plate test. A 10-day chronic CBDA treatment reduced despair-like behaviour in the tail suspension test. CBDA did not alter the remaining behavioural tests assayed, including cocaine-induced reward in the CPP. Regarding the biochemical analysis, chronic CBDA treatment diminished peroxisome proliferator-activated receptor gamma (PPAR-γ) and increased interleukin-6 (IL-6) protein levels in PFC.Significance these results show that CBDA has limited in vivo effects modulating mice behaviour, highlighting the current disagreement regarding its therapeutic potential.Competing Interest StatementThe authors have declared no competing interest.Abbreviations5-HT1ASerotonin receptor 1ACBDCannabidiolCBDACannabiodiolic acidCOX-2Ciclooxigenase-2CPPConditioned place preferenceEPMElevated plus mazeIL-6Interleukin-6PFCPrefrontal cortexPPARProliferator-activated receptorTRPA1Transient receptor potential cation channel ankyrin 1TRPM8Transient receptor potential cation channel melastatin 8TRPV1Transient receptor potential cation channel vanilloid 1TSTTail suspension testView Full Text

pharmacology and toxicology↗

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↗