Biology subjects

Gallego-Landin, I.

Publications and source records attributed to Gallego-Landin, I..

8 recordsLinked to original sources

bioRxiv2025

Prenatal alcohol exposure dysregulates the expression of clock genes and alters rhythmic behaviour in mice

Foetal Alcohol Spectrum Disorders (FASD) refer to a range of adverse physical, behavioural, and cognitive effects caused by perinatal alcohol exposure. While cognitive impairments are well-documented, FASD has also been associated with sleep disturbances and circadian rhythm disruptions. This study aimed to examine the effects of perinatal alcohol exposure on circadian rhythms at behavioural and gene expression levels across two developmental stages (adolescence and adulthood) in both, male and female mice. Using a validated prenatal and lactation alcohol exposure (PLAE) protocol, we assessed circadian patterns of locomotor activity under free-running conditions and spatial memory performance during adolescence and adulthood. Additionally, we evaluated the impact of PLAE on circadian expression of clock and non-circadian genes involved in neurotransmission across key brain regions, including the medial prefrontal cortex and hippocampus. PLAE altered circadian rhythmicity and impaired spatial memory. Gene expression analyses revealed disrupted oscillatory patterns in clock genes and in genes related to plasticity and cognition, including those from the expanded endocannabinoid system (e.g. Cnr1, Dagla, Faah) and other neurotransmitter systems (e.g. Oprm1, Slc17a8, Drd1, Gabra1). These findings underscore the impact of early alcohol exposure on biological rhythms and neurobehavioral function, highlighting circadian dysregulation as a contributing factor to FASD.

neuroscience↗

bioRxiv2024

Chronic circadian disruption in adolescent mice impairs hippocampal memory disrupting gene expression oscillations

Chronodisruption, the misalignment of internal biological systems with external environmental changes, leads to adverse health effects. Particularly, Social Jet Lag (SJL) is defined as the discrepancy between social and biological time and it exemplifies this misalignment, affecting a large part of the young population and impacting cognitive function. Despite its prevalence, our understanding of how developmental chronodisruption ultimately translates into morbidity is limited. To address this, we implemented a chronic chronodisruption protocol in adolescent mice consisting of light/dark cycle manipulation. We employed a comprehensive battery of established behavioral tests alongside an in-depth analysis of the oscillatory expression of the molecular clock and other genes involved in relevant physiological function. Our results show that chronic circadian disruption during adolescence induces impairments in short-term, social, and spatial memory without prompting anxiety-like behavior. Additionally, we report altered gene expression patterns of circadian clock genes per1, per2, cry2 and npas2 in the hypothalamus and the hippocampus. Lastly, we observed a disruption of hippocampal gene expression oscillations which may underlie the hippocampal memory impairments. Overall, this work underscores the critical role of adolescent circadian rhythms in maintaining cognitive function, the relevance of circadian control of hippocampal homeostasis, and the importance of further research into the mechanisms of chronodisruption, particularly during adolescence, to better understand its long-term implications for cognitive function and overall health.

neuroscience↗

bioRxiv2024

Irregular light schedules induce alterations on daily rhythms and gene expression in mice

Synchronization of internal biological rhythms with external light-dark cycles is crucial for proper function and survival of the organisms, however modern life often imposes irregular light exposure, disrupting these internal clocks. This study investigated the effects of short-term shifted light-dark cycles on mice rhythmicity, and whether these alterations trigger molecular or behavioral changes. We evaluated locomotor activity, different behavioral domains and gene expression in the hypothalamus and medial prefrontal cortex. Despite non prominent behavioral impairments, such as anxiety or cognitive deficits, we observed a notable simplification in the locomotor activity patterns of the mice subjected to disrupted light-dark cycles. Molecular alterations included dysregulations in oscillations of core clock genes (Cry2, Per2) and disruptions in expression of genes involved in neuroplasticity, motivation, and stress responses, including GluA1, Crhr2, and Vip in both studied brain areas. Our study reveals that even brief light cycle shifts can disrupt circadian regulation at the molecular level, despite minimal behavioral changes. This molecular-behavioral discrepancy may suggest a complex adaptive response to drastic short-term light perturbations. Understanding the complex interplay between external light cues and internal biological rhythms regulation is crucial for mitigating the negative consequences of irregular light exposure on physiological processes and overall well-being.

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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.

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bioRxiv2023

PPAR-γ is a promising therapeutic target for memory deficits induced by early alcohol exposure.

BackgroundPatients diagnosed with fetal alcohol spectrum disorder (FASD) show persistent cognitive disabilities, including memory deficits. However, the neurobiological substrates of these deficits remain unclear. Here, we studied the participation of the expanded endocannabinoid system (ECS), which is known to be affected by alcohol in other life periods, and it is involved in memory impairments of neurodevelopmental disorders. MethodsC57BL/6 female mice were exposed to a time-limited access to either water or alcohol to model prenatal and lactation alcohol exposure (PLAE). The expanded ECS was analyzed in the prefrontal cortex and the hippocampus of the offspring at post-partum day (PD) 25 and 70. Then, memory performance was tested after the repeated administration (from PD25 to PD34) of: i) URB597, to increase N-acylethanolamines (NAEs), and GW9662, a peroxisome proliferator-activated receptor gamma (PPAR-{gamma}) antagonist; ii) pioglitazone, a PPAR-{gamma} agonist. Finally, we used a viral approach to upregulate astrocytic PPAR-{gamma} in the hippocampus to restore memory deficits. ResultsWe report that PLAE causes a hippocampal reduction of NAEs and PPAR-{gamma} at PD25. Moreover, URB597 suppresses PLAE-induced memory deficits through PPAR-{gamma}, since its effects are prevented by GW9662. Direct PPAR-{gamma} activation, using pioglitazone, also ameliorates memory impairments. Lastly, we demonstrate that the upregulation of PPAR-{gamma} in hippocampal astrocytes is sufficient to rescue PLAE-induced memory deficits. ConclusionOur data reveal a bidirectional link between memory deficits and expanded ECS alterations in the context of early alcohol exposure. Furthermore, we proved that PPAR-{gamma} in hippocampal astrocytes represents a specific therapeutic target for memory deficits in FASD.

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bioRxiv2022

A novel mouse model of postpartum depression and the neurobiological effects of fast-acting antidepressant treatments

postpartum depression (PPD) is a severe psychiatric disorder that affects up to 15% of mothers and impairs mother-infant bonding with devastating consequences on the child development and the mother health. Several studies indicate a possible dysregulation of glutamatergic and GABAergic signalling in the corticolimbic system, as well as a downregulation of the allopregnanolone levels in serum of PPD patients. Although brexanolone, an allopregnanolone-based treatment, has recently emerged as fundamental PPD treatment, there is scarce evidence on its neurobiological action mechanism. Moreover, ketamine appears to be a promising antidepressant treatment preventing PPD, nevertheless whether it might be a more effective than allopregnanolone for some patients remain unknown. Therefore, the present study is aimed to evaluate the depressive-like phenotype of postpartum females undergoing maternal separation with early weaning (MSEW) protocol, as well as to compare the effectiveness of ketamine and allopregnanolone treatments. MSEW dams show increased despair-like behaviour, anhedonia and disrupted maternal behaviour. Moreover, lower allopregnanolone serum levels, reduction of vesicular transporters for GABA (VGAT) and glutamate (VGLUT1) in the infralimbic cortex, as well as decreased hippocampal cellular proliferation are found in MSEW females. As for the antidepressant treatments, both drugs prevent despair-like behaviour, whereas only ketamine reverts anhedonia present in MSEW females. In addition, both treatments induce pro-neurogenic effects in the dorsal hippocampus but only allopregnanolone increases the VGAT and VGLUT1, without altering the excitatory/inhibitory ratio. Altogether, we propose a new mice model that recapitulates the core symptomatology and alterations in glutamatergic and GABAergic systems shown in PPD patients, which allows us to investigate the therapeutic mechanisms of allopregnanolone and ketamine.

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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↗