Biology subjects

Costa, R. M.

Publications and source records attributed to Costa, R. M..

At least 19 recordsLinked to original sources

bioRxiv2026

GENETIC AND PHARMACOLOGIC ACTIVATION OF BECLIN1 PREVENTS ALDOSTERONE-INDUCED CARDIOVASCULAR DAMAGE

BackgroundAldosterone promotes endothelial dysfunction and cardiovascular injury through mineralocorticoid receptor (MR) activation. Autophagy is essential for endothelial homeostasis, yet its role in aldosterone-mediated vascular dysfunction remains unclear. We tested whether aldosterone impairs autophagic flux and whether restoring autophagy via Beclin1 (BCN1) activation protects vascular and cardiac function. MethodsEndothelial and vascular responses to aldosterone were assessed in wild-type mice, BCN1 gain-of-function mice (Becn1), and mice treated with spermidine or a BCN1- activating TB-peptide. Vascular function, nitric oxide (NO)/reactive oxygen species (ROS) production, autophagy markers, endothelial migration, and cardiac fibrosis were evaluated using wire myography, fluorescence assays, Western blotting, confocal microscopy, migration assays, and histology. ResultsAldosterone impaired endothelium-dependent relaxation, decreased NO, increased ROS, and disrupted autophagic flux in an MR-dependent manner, indicated by LC3 accumulation and reduced p62 and BCN1 expression. Spermidine restored endothelial function and normalized NO and ROS levels. BCN1 gain-of-function mice were protected from aldosterone-induced endothelial dysfunction and exhibited reduced coronary and myocardial fibrosis. TB-peptide activation of BCN1 enhanced autophagic flux, improved vascular function, decreased cardiac fibrosis, and rescued endothelial migration impaired by aldosterone. ConclusionsAldosterone induces endothelial dysfunction by suppressing autophagic flux through MR activation. Genetic or pharmacologic enhancement of BCN1-dependent autophagy restores endothelial homeostasis and prevents vascular and cardiac injury, identifying autophagy activation as a promising therapeutic approach for cardiovascular diseases associated with mineralocorticoid excess.

physiology↗

bioRxiv2026

Flexible route planning and rapid structure learning by mice in complex environments

Action selection using predictive models of the environment plays a fundamental role in human and animal behaviour, yet is poorly understood at circuit and algorithmic levels. Spatial navigation is an attractive domain for characterising how world models guide action selection. However spatial behaviours are shaped by multiple control systems including habits, vector-navigation using a Euclidean model of spatial relationships, and route planning using models of environment structure. Understanding how world models support navigation requires assays that dissociate control systems and decorrelate behavioural variables, while generating large datasets that allow precise quantification of brain-behaviour relationships. Here we developed and computationally optimised a behavioural assay to quantify flexible navigation using knowledge of environment structure. Mice navigated to visually cued goals in complex mazes, with randomised start and goal locations on each trial, generating thousands of non-repetitive goal-directed navigation trajectories. They navigated efficiently - strongly favouring options on the shortest path-to-goal, and learnt rapidly - demonstrating knowledge of maze structure from their first sessions in new environments. We anticipate the assay will be useful for characterising how world models support flexible behaviour.

animal behavior and cognition↗

bioRxiv2026

TNF-α-Driven NOX5 Activation Promotes Oxidative Stress and Umbilical Artery Dysfunction in Preeclampsia

BackgroundPreeclampsia (PE) is a hypertensive disorder of pregnancy characterized by systemic inflammation, oxidative stress, and endothelial dysfunction. Although maternal vascular dysfunction is well established in PE, the mechanisms underlying fetal vascular injury remain poorly understood. We investigated whether inflammatory signaling activates NADPH oxidase 5 (NOX5) and contributes to oxidative stress and dysfunction in human umbilical arteries from pregnancies complicated by PE. MethodsUmbilical arteries and serum samples were obtained from normotensive pregnant women (NP) and women with PE. Vascular reactivity, nitric oxide (NO) bioavailability, reactive oxygen species (ROS) generation, cytokine levels, and NOX isoform expression were evaluated in human umbilical arteries and EA.hy926 endothelial cells. Pharmacological inhibition of NOX5, TNF- neutralization, Ca{superscript 2} channel blockade, and siRNA-mediated NOX5 silencing were used to investigate mechanisms. ResultsPE umbilical arteries exhibited increased vasoconstrictor responses, oxidative stress, and NOX5 expression, accompanied by impairment of NO bioavailability. NOX5 inhibition reversed vascular hyperreactivity in PE vessels. Exposure of normotensive umbilical arteries to PE serum reproduced the PE vascular phenotype, characterized by enhanced ROS generation, reduced NO levels, and hypercontractility. In endothelial cells, PE serum induced TNF--dependent Ca{superscript 2} influx, oxidative stress, and reduced NO production. Both pharmacological and genetic inhibition of NOX5 prevented these alterations. ConclusionsPE promotes fetal vascular dysfunction through activation of a TNF-/Ca2+/NOX5 signaling pathway that amplifies oxidative stress and impairs NO bioavailability. These findings identify NOX5 as a previously unrecognized mediator of umbilical artery dysfunction in PE and suggest the TNF-/Ca2+/NOX5 axis as a potential therapeutic target in hypertensive pregnancies.

molecular biology↗

bioRxiv2026

The External Globus Pallidus is a Basal Ganglia Output Hub with Action-Specific Circuits

The external globus pallidus (GPe) is traditionally viewed as a homogeneous relay in the indirect basal ganglia pathway that broadly suppresses movement. Using whole-brain anterograde axon mapping, rabies tracing, single-neuron reconstruction, and single-nucleus RNA sequencing, we reveal that the GPe is a major basal ganglia output nucleus, composed of anatomically and molecularly distinct populations. Besides the neurons with canonical projections, and projections to striatum and cortex, the GPe contains specific neuronal populations that target the thalamus and brainstem directly, including the parafascicular thalamus (GPePf) and the pedunculopontine nucleus (GPePPN). These projection-defined subpopulations exhibit distinct behavioral functions. GPe-PPN neurons are selectively suppressed at locomotor onset, and bidirectional manipulation of this pathway is sufficient to promote or suppress locomotion. Notably, D2-MSN stimulation upstream of these neurons evokes locomotion, and co-activation of GPePPN pathway blocks this D2-MSN-evoked locomotion, demonstrating a disinhibitory circuit for action stemming from D2-MSNs. In contrast, GPePf neurons are not engaged during locomotion but are selectively recruited during skilled forelimb actions, and their activation disrupts forelimb movements without affecting locomotion. Together, these findings establish the GPe as a basal ganglia output hub composed of modules that mediate distinct behaviors. This organization revises canonical models of the indirect pathway by demonstrating that D2-MSNs can also facilitate, rather than only suppress, movement depending on the downstream GPe output channels they engage. In briefThe external globus pallidus (GPe), classically considered a relatively homogeneous relay within the indirect basal ganglia pathway, is revealed here as a major basal ganglia output hub. Distinct GPe subpopulations, defined by transcriptomic identity and projection target, form parallel channels to cortical, thalamic and brainstem structures with action-specific functions. These findings uncover a disinhibitory mechanism through which D2-MSNs can facilitate behavior, revising canonical models of basal ganglia function. HighlightsBrain-wide mapping reveals the GPe as a major basal ganglia output node GPe contains novel cell types defined by transcriptomic identity and projection specificity Projection-specific GPe circuits differentially control locomotion and skilled forelimb actions D2-MSNs can disinhibit downstream targets via specific GPe projections and promote action.

neuroscience↗

bioRxiv2025

Striatal ensembles specify and control granular forelimb actions

The striatum is classically thought to modulate action vigor and reinforcement, but whether it specifies and controls ongoing actions at a fine scale remains unclear. Here, we test whether striatal activity can resolve and control actions as granular as distinct patterns of muscle co-contraction within the same limb. We developed a closed-loop system combining two-photon imaging and holographic optogenetics to identify and manipulate action-specific striatal ensembles in real time. Mice performed isometric push or pull actions engaging the same forelimb muscles with different activation patterns. Ensembles of both D1- and D2-spiny projection neurons encoded action identity with equal fidelity. Causal stimulation of small ensembles biased ongoing force, but only when the ensembles encoded the ongoing action. These results show that the striatum specifies and controls ongoing actions in real time at a previously unappreciated granularity, redefining its role in motor control.

neuroscience↗

bioRxiv2025

Progranulin deficiency aggravates aging-induced vascular injury

SignificanceVascular aging is a major contributor to cardiovascular disease, yet the molecular mechanisms of age-associated vascular dysfunction remain incompletely defined. This study reveals a critical role for progranulin (PGRN) in regulating vascular senescence, function, and remodeling during aging. MethodsWe assessed PGRN expression in human and mouse arteries and senescent vascular smooth muscle cells (VSMCs). Functional vascular studies were performed in PGRN-deficient (PGRN-/-) mice. Senescence was modulated pharmacologically using the senolytic agent navitoclax (ABT-263), and vascular phenotype was evaluated in adult (6-month-old) and aged mice (18-month-old). ResultsPGRN expression increased with age in human and mouse arteries, correlating with elevated p21 expression. PGRN deficiency in adult mice induced endothelial dysfunction, increased vasoconstriction, and induced vascular inflammation and remodeling. Transcriptomic analysis of PGRN-/- VSMCs revealed a senescence-associated signature, including perturbed oxidative phosphorylation, altered epigenetic regulation, and collagen pathways. Pharmacological clearance of senescent cells improved endothelial function but increased vascular contractility in PGRN-/- mice. In aged mice, PGRN deficiency aggravated vascular dysfunction, remodeling, and renal injury without further increasing senescence markers--suggesting premature, rather than progressive, senescence in the PGRN-/- mice. ConclusionPGRN is a novel regulator of vascular aging, coordinating senescence, inflammation, and remodeling. While endothelial senescence contributes to dysfunction, VSMCs senescence may serve an adaptive role in modulating vascular tone. Targeting PGRN or senescence pathways may offer therapeutic opportunities for age-related vascular diseases, especially in patients with PGRN mutations associated with frontotemporal dementia.

cell biology↗

bioRxiv2025

Network dynamics underlying activity-timescale differences between cortical regions

Network-level dynamics are thought to be central to computation in the cerebral cortex. Yet, how these dynamics differ across areas remains poorly understood. We leveraged an intrinsic property of cortical regions to tackle this problem -- the timescales over which they spontaneously sustain activity. We first co-registered functional and spatial transcriptomics datasets to show that timescales across the mouse cortex are predicted by many transcript categories, including those that regulate circuit wiring. Next, we used simultaneous two-photon imaging and optogenetics in mice to ask how these putative differences in connectivity lead to distinct network responses to brief, focal excitatory input to a short-timescale visual area, VISp, and a long-timescale frontal area, MOs. MOs neurons were more likely to respond to photostimulation of their neighbors. Moreover, the evoked dynamics of the overall network were much longer lasting in MOs than VISp, due to the more prevalent recruitment of late-responding neurons, which formed reliable activity sequences. Overall, our findings show that, beyond single-neuron timescales, different cortical areas are distinctly wired to sustain input over varying time windows via network dynamics, with important implications for our understanding of cortical computation.

neuroscience↗

bioRxiv2025

Internal and external contexts drive distinct dynamics in shared action-encoding striatal neurons

Animals can initiate movements either in response to external cues or from internal drive, yet how the brain flexibly supports both remains unclear. Disorders such as Parkinsons disease disrupt these modes differently, suggesting distinct underlying mechanisms. Such differences could arise from specialized circuits dedicated to each action mode or from shared neuronal populations that shift their dynamics across contexts. To distinguish between these possibilities, we performed two-photon calcium imaging in the dorsolateral striatum as mice executed the same lever press either spontaneously or in response to a cue, enabling direct comparison of internally and externally triggered actions. Unsupervised clustering revealed subpopulations of neurons modulated during cue, movement, or post-action periods. Critically, the same neurons were tuned to movement across initiation contexts. However, the dynamics of this shared population evolved within distinct "context" and "action" subspaces, even before movement initiation. Both dopamine D1- and D2-receptor-expressing spiny projection neurons contributed to both subspaces, with D1-SPNs more active at the time of the sensory stimulus. These results show that context shapes neural dynamics within a shared movement-encoding population, revealing a context-generalizable striatal code that supports flexible movement initiation across internal and external drives.

neuroscience↗

bioRxiv2025

Cognitive processes are disentangled at cortex-wide scales

Most decisions involve multiple cognitive processes. Recent findings suggest that these processes are distributed across the cortex1-21, but that single regions implement them via orthogonal population-activity patterns14,21-33. How are these local geometries combined across the cortex? Here, we designed a virtual-navigation task for mice that dissociates the accumulation and short-term memory of sensory evidence, and choice. Combining dimensionality reduction and decoding models with cortex-wide widefield Ca2+ imaging, we observed distributed but near-orthogonal coding subspaces for these different cognitive processes, and that this geometry breaks down during erroneous choices. Further, only the memory subspace corresponded to a spontaneous activity-timescale hierarchy, suggesting that it co-opts intrinsic circuit properties. Thus, we reconcile previous findings by showing that cortex-wide dynamics supporting distinct cognitive processes are disentangled.

neuroscience↗

bioRxiv2025

Generation of knock-in Cre and FlpO mouse lines for precise targeting of striatal projection neurons and dopaminergic neurons

The basal ganglia and midbrain dopaminergic systems are critical for motor control, reward processing, and reinforcement learning, with dysfunction in these systems implicated in numerous neurodegenerative and neuropsychiatric disorders. To enable precise genetic targeting of key neuronal populations, we generated and characterized five knock-in mouse lines: Drd1-Cre, Adora2a-Cre, Drd1-FlpO, Adora2a-FlpO, and DAT-FlpO. These lines allow for Cre-or FlpO-mediated recombination in dopamine D1 receptor-expressing spiny projection neurons (SPNs), adenosine A2a receptor-expressing SPNs, and dopamine transporter (DAT)-expressing neurons in the midbrain. Histological analyses confirmed recombinase activity in expected brain regions, and whole-cell electrophysiological recordings validated the intrinsic excitability profiles of each neuronal subpopulation. These tools provide high specificity and reliability for studying basal ganglia circuitry and dopaminergic neurons. By enabling targeted manipulations, these openly available knock-in lines will advance research into the neural mechanisms underlying motor control, reward, and neuropsychiatric diseases.

neuroscience↗

bioRxiv2025

Influenza virus evolution and defective genome formation are shaped by host genotype and sex

Viral evolution during initial pandemic waves favors mutations that enhance replication and transmission over antigenic escape. Host genotype and sex strongly shape this early adaptation, yet their individual and combined effects remain unclear. We experimentally adapted influenza A virus to male and female BALB/c and C57BL/6 mice, generating 28 independent lineages, and employed a novel "rolling sphere" approach to identify mutational hotspots in three-dimensional protein structures. In BALB/c mice, adaptation favored nonsynonymous substitutions linked to increased virulence, including a hemagglutinin variant exclusively fixed in female lineages. It also revealed the first demonstration of sex-dependent selection shaping a viral protein interface. In female-adapted viruses, substitutions disrupting a key NS1 dimerization motif converged on a single residue, while in male-adapted viruses, they were dispersed across the same interface. Conversely, adaptation to C57BL/6 resulted in fewer substitutions but promoted defective viral genome formation, leading to reduced cytopathic effect and attenuated virulence. This provides the first in vivo evidence that host genotype alone can modulate defective viral genome formation. Our results offer critical insights into host-pathogen interactions and reveal that selective pressures imposed by specific genotype-sex combinations can increase virulence across host genotypes, enabling new epidemiological modeling and disease control strategies.

evolutionary biology↗

bioRxiv2024

A Vulnerable Subtype of Dopaminergic Neurons Drives Early Motor Deficits in Parkinson's Disease

In Parkinsons disease (PD), dopaminergic neurons (DANs) in the midbrain gradually degenerate, with ventral substantia nigra pars compacta (SNc) DANs exhibiting greater vulnerability. However, it remains unclear whether specific molecular subtypes of ventral SNc DANs are more susceptible to degeneration in PD, and if they contribute to the early motor symptoms associated with the disease. We identified a subtype of Sox6+ DANs, Anxa1+, which are selectively lost earlier than other DANs, and with a time course that aligns with the development of motor symptoms in MitoPark mice. We generated a knock-in Cre mouse line for Anxa1+ DANs and showed differential anatomical inputs and outputs of this population. Further, we found that the inhibition of transmitter release in Anxa1+ neurons led to bradykinesia and tremor. Therefore, Anxa1+ is not only a biomarker of a selectively vulnerable subtype of DANs, but is also sufficient to drive early motor symptoms in Parkinsons disease.

neuroscience↗

bioRxiv2024

Abnormal hyperactivity of specific striatal ensembles encodes distinct dyskinetic behaviors revealed by high-resolution clustering

L-DOPA-induced dyskinesia (LID) is a debilitating complication of dopamine replacement therapy in Parkinso[n]s disease and the most common hyperkinetic disorder of basal ganglia origin. Abnormal activity of striatal D1 and D2 spiny projection neurons (SPNs) is critical for LID, yet the link between SPN activity patterns and specific dyskinetic movements remains unknown. To explore this, we developed a novel method for clustering movements based on high-resolution motion sensors and video recordings. In a mouse model of LID, this method identified two main dyskinesia types and pathological rotations, all absent during normal behavior. Using single-cell resolution imaging, we found that specific sets of both D1 and D2-SPNs were abnormally active during these pathological movements. Under baseline conditions, the same SPN sets were active during behaviors sharing physical features with LID movements. These findings indicate that ensembles of behavior-encoding D1- and D2-SPNs form new combinations of hyperactive neurons mediating specific dyskinetic movements.

neuroscience↗

bioRxiv2024

Distinct anatomical and functional corticospinal inputs innervate different spinal neuron types

The corticospinal tract exerts its influence on movement through spinal neurons, which can be divided into types that exhibit distinct functions. However, it remains unknown whether these functional distinctions are reflected in the corticospinal inputs that different types of spinal neurons receive. Using rabies monosynaptic tracing from individual neuron types in the cervical cord and 3D histological reconstruction in mice, we discovered that different types receive inputs distinctly distributed across cortex, and aligned with cell type function. This included a distinct, sparse distribution of direct inputs from cortex onto motor neurons. Coupling rabies tracing with activity measurement during motor behavior revealed different interneuron types receive different input activity patterns, primarily due to the topographical distribution of the corticospinal neurons contacting them. Our results establish that different spinal neuron types get distinct anatomical and functional inputs from the cortex, and reveal functionally relevant homology to primate corticospinal organization.

neuroscience↗

bioRxiv2024

Dynamic representation of appetitive and aversive stimuli in nucleus accumbens shell D1- and D2-medium spiny neurons

The nucleus accumbens (NAc) is a key brain region for motivated behaviors, yet how distinct neuronal populations encode appetitive or aversive stimuli remains undetermined. Using microendoscopic calcium imaging, we tracked NAc shell D1- or D2-medium spiny neurons (MSNs) activity during exposure to stimuli of opposing valence and associative learning. Despite drift in individual neurons coding, both D1- and D2-population activity was sufficient to discriminate opposing valence unconditioned stimuli, but not predictive cues. Notably, D1- and D2-MSNs were similarly co-recruited during appetitive and aversive conditioning, supporting a concurrent role in associative learning. Conversely, when contingencies changed, there was an asymmetric response in the NAc, with more pronounced changes in the activity of D2-MSNs. Optogenetic manipulation of D2-MSNs provided causal evidence of the necessity of this population in the extinction of aversive associations. Our results reveal how NAc shell neurons encode valence, Pavlovian associations and their extinction, and unveil new mechanisms underlying motivated behaviors.

neuroscience↗

bioRxiv2023

Topographical and cell type-specific connectivity of rostral and caudal forelimb corticospinal neuron populations

Corticospinal neurons (CSNs) synapse directly on spinal neurons, a diverse group of neurons with unique structural and functional properties necessary for body movements. CSNs modulating forelimb behavior fractionate into caudal forelimb area (CFA) and rostral forelimb area (RFA) motor cortical populations. Despite their prominence, no studies have mapped the diversity of spinal cell types targeted by CSNs, let alone compare CFA and RFA populations. Here we use anatomical and RNA-sequencing methods to show that CSNs synapse onto a remarkably selective group of spinal cell types, favoring inhibitory populations that regulate motoneuron activity and gate sensory feedback. CFA and RFA CSNs target similar spinal cell types, with notable exceptions that suggest these populations differ in how they influence behavior. Finally, axon collaterals of CFA and RFA CSNs target similar brain regions yet receive surprisingly divergent inputs. These results detail the rules of CSN connectivity throughout the brain and spinal cord for two regions critical for forelimb behavior.

neuroscience↗

bioRxiv2023

Adjusted vascular contractility relies on integrity of progranulin pathway: Insights into mitochondrial function

ObjectiveCardiovascular disease (CVD) is a global health crisis and a leading cause of mortality. The intricate interplay between vascular contractility and mitochondrial function is central to CVD pathogenesis. The progranulin gene (GRN) encodes glycoprotein progranulin (PGRN), a ubiquitous molecule with known anti-inflammatory property. However, the role of PGRN in CVD remains enigmatic. In this study, we sought to dissect the significance of PGRN in the regulation vascular contractility and investigate the interface between PGRN and mitochondrial quality. MethodOur investigation utilized aortae from male and female C57BL6/J wild-type (PGRN+/+) and B6(Cg)-Grntm1.1Aidi/J (PGRN-/-) mice, encompassing wire myograph assays to assess vascular contractility and primary aortic vascular smooth muscle cells (VSMCs) for mechanistic insights. ResultsOur results showed suppression of contractile activity in PGRN-/- VSMCs and aorta, followed by reduced -smooth muscle actin expression. Mechanistically, PGRN deficiency impaired mitochondrial oxygen consumption rate (OCR), complex I activity, mitochondrial turnover, and mitochondrial redox signaling, while restoration of PGRN levels in aortae from PGRN-/- mice via lentivirus delivery ameliorated contractility and boosted OCR. In addition, VSMC overexpressing PGRN displayed higher mitochondrial respiration and complex I activity accompanied by cellular hypercontractility. Furthermore, increased PGRN triggered lysosome biogenesis by regulating transcription factor EB and accelerated mitophagy flux in VSMC, while treatment with spermidine, an autophagy inducer, improved mitochondrial phenotype and enhanced vascular contractility. Finally, angiotensin II failed to induce vascular contractility in PGRN-/- suggesting a key role of PGRN to maintain the vascular tone. ConclusionOur findings suggest that PGRN preserves the vascular contractility via regulating mitophagy flux, mitochondrial complex I activity, and redox signaling. Therefore, loss of PGRN function appears as a pivotal risk factor in CVD development.

pharmacology and toxicology↗

bioRxiv2023

Role Of The C-C Motif Chemokine Ligand 5 (CCL5) And Its Receptor, C-C Motif Chemokine Receptor 5 (CCR5) In The Genesis Of Aldosterone-induced Hypertension, Vascular Dysfunction, And End-organ Damage

BackgroundAldosterone, a mineralocorticoid steroid hormone, has been described to initiate cardiovascular diseases by triggering exacerbated sterile vascular inflammation. The functions of C-C Motif Chemokine Ligand 5 (CCL5) and its receptor, C-C Motif Chemokine Receptor 5 (CCR5), are well known in infectious diseases, but their roles in the genesis of aldosterone-induced vascular injury and hypertension are unknown. MethodsWe analyzed the vascular profile, blood pressure, and renal damage in wild-type (CCR5+/+) and CCR5 knockout (CCR5-/-) mice treated with aldosterone (600 {micro}g/kg/day for 14 days) while receiving 1% saline to drink. ResultsHere, we show that CCR5 plays a central role in aldosterone-induced vascular injury, hypertension, and renal damage. Long-term infusion of aldosterone in CCR5+/+ mice resulted in exaggerated CCL5 circulating levels and vascular CCR5 expression. Aldosterone treatment also triggered vascular injury, characterized by endothelial dysfunction and inflammation, hypertension, and renal damage. Mice lacking CCR5 were protected from aldosterone-induced vascular damage, hypertension, and renal injury. Mechanistically, we demonstrated that CCL5 increased NADPH oxidase 1 (Nox1) expression, reactive oxygen species (ROS) formation, NF{kappa}B activation, and inflammation and reduced nitric oxide production in isolated endothelial cells. These effects were abolished by antagonizing CCR5 with Maraviroc. Finally, aortae incubated with CCL5 displayed severe endothelial dysfunction, which is prevented by blocking Nox1, NF{kappa}B, or with Maraviroc treatment. ConclusionsOur data demonstrate that CCL5/CCR5, through activation of NFkB and Nox1, is critically involved in aldosterone-induced vascular and renal damage and hypertension. Our data place CCL5 and CCR5 as potential targets for therapeutic interventions in conditions with aldosterone excess.

pharmacology and toxicology↗