Miguel Castelo-Branco

University of Coimbra | UC · Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT)

MRI imaging with long acquisition times is prone to motion artifacts that can compromise image quality and lead to misinterpretation. Aiming to address this challenge at the sub-millimeter level, we developed and evaluated a maxilla immobilization approach, which is known to have better performance than other non-invasive techniques, using a person...

Neurodegenerative Diseases (NDs) are a major health challenge. Thus, finding reliable blood biomarkers for them has been of pivotal importance in translational/clinical research. However, conventional omics struggle with the complexity of blood samples making it difficult to achieve the desired goal. To address this, the potential of High Molecular...

In recent years, our understanding of the physiological role of kisspeptin (Kiss1) has evolved significantly, revealing its pivotal role in shaping sexual differentiation within the brain. Predominantly expressed in the hypothalamus, Kiss1 plays a crucial role in regulating release of the gonadotrophin-releasing hormone (GnRH). Kisspeptin 1 recepto...

Background Plasma biomarkers reflecting the pathology of frontotemporal dementia would add significant value to clinical practice, to the design and implementation of treatment trials as well as our understanding of disease mechanisms. The aim of this study was to explore the levels of multiple plasma proteins in individuals from families with gene...

Experimental approaches in neuroeconomics generally involve monetary utility. Utility in the health domain is relevant in diabetes because constant daily life decisions are critical for self-consequential long-term outcomes. We used fMRI to investigate self-consequent decision-making in the health and economic domains in Type 1 Diabetes Mellitus an...

Introduction Positron emission tomography-computed tomography (PET-CT) with 18F-sodium fluoride (18F-NaF) has been used in clinical research to characterize active microcalcification in aortic valve disease. However, its role in apparently healthy patients remains unknown. Purpose We aimed to characterize the aortic valve uptake of 18F-NaF in pati...

Background Sodium fluoride (18F-NaF) uptake in positron emission tomography with computed tomography (PET-CT) identifies active microcalcification both in atherosclerotic plaques and the aortic valve. Purpose We aimed to evaluate global cardiac microcalcification activity with 18F-NaF, as a measure of the microcalcification burden, in high cardiov...

Type 2 diabetes has an effect on brain structure, including cortical gyrification. The significance of these changes is better understood if assessed over time. However, there is a lack of studies assessing longitudinally the effect of this disease with complex aethology in gyrification. While changes in this feature have been associated mainly wit...

Considering the nonlinear dynamic nature of emotion recognition, it is believed to be strongly dependent on temporal context. This can be investigated by resorting to the phenomenon of hysteresis, which features a form of serial dependence, entailed by continuous temporal stimulus trajectories. Under positive hysteresis, the percept remains stable...

Introduction The presence of post-traumatic stress disorder ( PTSD) symptomatology in firefighters is an ever-pressing issue that requires close attention for adequate interventions. The present study investigated PTSD and global psychopathology prevalence in a sample of highly risk-exposed Portuguese firefighters, collected after the widespread de...

More realistic assessment tools are imperative for a better understanding of the impact of age-related cognitive deficits on functional status. With this in mind, we probed the ability of the EcoKitchen, a non-immersive virtual environment task with increasing executively demanding kitchen chores, to detect the effects of aging on the simulated eve...

Inhibition is implicated across virtually all human experiences. As a trade-off of being very efficient, inhibition is also prone to many errors. Rodent and computational studies show that midbrain regions play crucial roles during errors by sending dopaminergic learning signals to the basal ganglia for behavioural adjustment. However, the parallel...

Introduction: Autism is a common neurodevelopmental condition with a complex genetic aetiology that includes contributions from monogenic and polygenic factors. Many autistic people have unmet healthcare needs that could be served by genomics-informed research and clinical trials. The primary aim of the European Autism GEnomics Registry (EAGER) is...

Cine cardiac magnetic resonance (CMR) imaging is considered the gold standard for cardiac function evaluation. However, cine CMR acquisition is inherently slow and in recent decades considerable effort has been put into accelerating scan times without compromising image quality or the accuracy of derived results. In this paper, we present a fully-a...

The Ruminative Response Scale for Eating Disorders (RRS-ED) measures ruminative thought content specifically related to eating disordered themes, assessing two domains of rumination, brooding and reflection. This study aims to examine the factor structure of the RRS-ED in a Portuguese community sample, using correlated two-factor models, unifactori...

Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback (NF), a training method for the self-regulation of brain activity, has shown promising results as a neurorehabilitation tool, depending on the ability of the patient to succeed in neuromodulation. This study explores connectivity-based structural and functional success predicto...

This study uses neuroimaging methods to identify patterns of brain activation among sport fans in reaction to team stimuli. In a whole-brain analysis without selected regions in advance, the purposes were to identify the structures involved when fans are exposed to positive, neutral, and negative events and to learn what events activate more limbic...

Background: Functional neuroimaging can provide pathophysiological information in perinatal asphyxia (PA). However, fundamental unresolved questions remain related to the influence of neurovascular coupling (NVC) maturation on functional responses in early development. We aimed to probe the feasibility and compare the responses to multiple sensory...

Multiple sclerosis (MS), namely the phenotype of the relapsing-remitting form, is the most common white matter disease and is mostly characterized by demyelination and inflammation, which lead to neurodegeneration and cognitive decline. Its diagnosis and monitoring are performed through conventional structural MRI, in which T2-hyperintense lesions...

Peripheral signs of age‐related hearing loss (ARHL) have been well documented, although ARHL is not well understood if it contributes to adaptive plasticity of cortical regions and how it interacts with functional responses of high‐order centers associated with cognitive function. Therefore, the present study investigates electrophysiological audit...

Color perception entails competing temporal context mechanisms such as adaptation versus memory persistence ¹ . Perceptual dynamics in color cone pathways can be studied using the phenomenon of hysteresis, well-known in the framework of physical dynamical systems. It postulates analogous mechanisms: a) visual persistence defining positive hysteresi...

Deep learning (DL) are data-driven models that learn abstract, hierarchical features from raw or low-processed data. These models perform exceptionally in image recognition tasks using large amounts of data. Thus, the availability of open-source large-scale annotated datasets is crucial to achieve high-performance models. Nevertheless, the usage of...

Addiction to psychoactive substances is a maladaptive learned behavior. Contexts surrounding drug use integrate this aberrant mnemonic process and hold strong relapse triggering ability. Here we asked where context and salience might be concurrently represented in the brain, and found circuitry hubs specific to morphine-related contextual informati...

The activity of neurons is influenced by random fluctuations and can be strongly modulated by firing rate adaptation, particularly in sensory systems. Still, there is ongoing debate about the characteristics of neuronal noise and the mechanisms of adaptation, and even less is known about how exactly they affect perception. Noise and adaptation are...

The Default Mode Network (DMN) and the Theory of Mind (ToM) networks play a crucial role in our understanding of the neurocognition of the self. The DMN is commonly associated with introspection, while the ToM is involved in perspective-taking. There is no research investigating the overlap between the DMN and ToM in relation to causal effects such...

Background: This study aimed to compare brain asymmetry in patients with schizophrenia (SCZ), bipolar disorder (BPD), and healthy controls to test whether asymmetry patterns could discriminate and set boundaries between two partially overlapping severe mental disorders. Methods: We applied a fully automated voxel-based morphometry (VBM) approach...

Alzheimer’s disease is the most common form of dementia worldwide, accounting for 60–70% of diagnosed cases. According to the current understanding of molecular pathogenesis, the main hallmarks of this disease are the abnormal accumulation of amyloid plaques and neurofibrillary tangles. Therefore, biomarkers reflecting these underlying biological m...

Research into the neurobiological and psychosocial mechanisms involved in fibromyalgia has progressed remarkably in recent years. Despite this, current accounts of fibromyalgia fail to capture the complex, dynamic, and mutual crosstalk between neurophysiological and psychosocial domains. We conducted a comprehensive review of the existing literatur...

Background Neurofibromatosis type 1 (NF1) is an inherited neurocutaneous disorder associated with neurodevelopmental disorders including autism spectrum disorder (ASD). This condition has been associated with an increase of gamma-aminobutyric acid (GABA) neurotransmission and, consequently, an excitation/inhibition imbalance associated with autisti...

Functional MRI (fMRI) with 1 H-MRS were combined on the hippocampus and visual cortex of animal models of obesity (high-fat diet, HFD) and type 2 diabetes (T2D) to identify the mechanisms involved and the temporal evolution of neurometabolic changes in these disorders that could serve as potentially reliable clinical biomarkers. HFD rats presented...

There is a pressing need for novel diagnostic and progression biomarkers of neurodegeneration. However, the inability to determine disease duration and stage in patients with Alzheimer’s disease (AD) hinders their discovery. Because animal models of disease allow us to circumvent some of these limitations, they have proven to be of paramount import...

Animal models of disease are paramount to understand retinal development, the pathophysiology of eye diseases, and to study neurodegeneration using optical coherence tomography (OCT) data. In this study, we present a comprehensive normative database of retinal thickness in C57BL6/129S mice using spectral-domain OCT data. The database covers a longi...

This paper introduces a prototype for clinical research documentation using the structured information model HL7 CDA and clinical terminology (SNOMED CT). The proposed solution was integrated with the current electronic health record system (EHR-S) and aimed to implement interoperability and structure information, and to create a collaborative plat...

Tryptophan (Tryp) is an essential amino acid and the precursor of several neuroactive compounds within the central nervous system (CNS). Tryp metabolism, the common denominator linking serotonin (5-HT) dysfunctions and neuroinflammation, is involved in several neuropsychiatric conditions, including neurological, neurodevelopmental, neurodegenerativ...

Background: Blood-brain barrier permeability (BBBp) is key process involved in ischemic stroke pathophysiology. However, there is a lack of consensus on how BBBp evolves after the ischaemic injury, and its clinical relevance at different time points post stroke. Aims: To assess BBBp evolution through stroke phases, and its implications on patien...

Memory-related impairments in type 2 diabetes maybe be mediated by insulin resistance and hyperglycemia. Previous cross-sectional studies have controversially suggested a relationship between metabolic control and a decrease in hippocampal volumes, but only longitudinal studies can test this hypothesis directly. We performed a longitudinal morphome...

Biomarkers that can predict disease progression in individuals with genetic frontotemporal dementia are urgently needed. We aimed to identify whether baseline MRI-based grey and white matter abnormalities are associated with different clinical progression profiles in presymptomatic mutation carriers in the GENetic Frontotemporal dementia Initiative...

Assessing the molecular mechanism of synaptic plasticity in the cortex is vital for identifying potential targets in conditions marked by defective plasticity. In plasticity research, the visual cortex represents a target model for intense investigation, partly due to the availability of different in vivo plasticity-induction protocols. Here, we re...

A model based on inhibitory coupling has been proposed to explain perceptual oscillations. This ‘adapting reciprocal inhibition’ model postulates that it is the strength of inhibitory coupling that determines the fate of competition between percepts. Here, we used an fMRI-based adaptation technique to reveal the influence of neighboring neuronal po...

Objective Brain atrophy has been consistently associated with type 2 diabetes, beginning in early stages of dysglycemia, independently from micro and macrovascular complications. On the contrary, physical activity relates with larger brain volumes. Our aim is to assess the influence of regular physical activity on brain volumes in people with type...

Exploration of the physical environment is an indispensable precursor to data acquisition and enables knowledge generation via analytical or direct trialing. Artificial Intelligence lacks the exploratory capabilities of even the most underdeveloped organisms, hindering its autonomy and adaptability. Supported by cognitive psychology, this works lin...

Functional near-infrared spectroscopy (fNIRS) provides a cost-efficient and portable alternative to functional magnetic resonance imaging (fMRI) for assessing cortical activity changes based on hemodynamic signals. The spatial and temporal underpinnings of the fMRI blood-oxygen-level-dependent (BOLD) signal and corresponding fNIRS concentration of...

Complexity is the key element of software quality. This article investigates the problem of measuring code complexity and discusses the results of a controlled experiment to compare different views and methods to measure code complexity. Participants (27 programmers) were asked to read and (try to) understand a set of programs, while the complexity...

Purpose: We aim to report about effectiveness and safety in the context of our centers' setting in the management of retinoblastoma with intra-arterial chemotherapy (IAC) in a 5-year retrospective analysis of the Portuguese population. Patients and methods: Retrospective analysis of consecutive cases of retinoblastoma selected to initiate IAC be...

Executive functions and motivation have been established as key aspects for neurofeedback success. However, task-specific influence of cognitive strategies is scarcely explored. In this study, we test the ability to modulate the dorsolateral prefrontal cortex, a strong candidate for clinical application of neurofeedback in several disorders with dy...

Functional magnetic resonance imaging (fMRI) has been extensively used as a tool to map the brain processes related to somatosensory stimulation. This mapping includes the localization of task-related brain activation and the characterization of brain activity dynamics and neural circuitries related to the processing of somatosensory information. H...

The activity of neurons is influenced by random fluctuations and can be strongly modulated by firing rate adaptation, especially in sensory systems. Still, there is an ongoing debate about the characteristics of neuronal noise and the mechanisms of adaptation, and even less is known about how exactly they affect perception. Noise and adaptation pla...

Type 2 Diabetes Mellitus (T2DM) is a metabolic disease that leads to multiple vascular complications with concomitant changes in human neurophysiology, which may lead to long-term cognitive impairment, and dementia. Early impairments of neurovascular coupling can be studied using event-related functional magnetic resonance imaging (fMRI) designs. H...

Unlabelled: Reliably assessing the early neurodevelopmental outcomes in infants with neonatal encephalopathy (NE) is of utmost importance to advise parents and implement early and personalized interventions. We aimed to evaluate the accuracy of neuroimaging modalities, including functional magnetic resonance imaging (fMRI) in predicting neurodevel...

One of the earliest signs of diabetic retinopathy is the appearance of small and round red dots in retinal fundus images, known as microaneurysms. Microaneurysms automatic detection is a challenging task due to their small and subtle nature. In this paper, a new multi-scale algorithm developed for the automatic detection of microaneurysms in retina...

Using two imaging modalities, that is, Pittsburgh compound B (PiB) positron emission tomography (PET) and diffusion tensor imaging (DTI) the present study tested associations between cortical amyloid-beta (Aβ) burden and fornix microstructural changes with cognitive deficits in early Alzheimer's disease (AD), namely deficits in working memory (1-ba...

Background Behavioural variant fronto-temporal dementia (bvFTD) is characterised by a progressive change in personality in association with atrophy of the frontal and temporal lobes. Whilst language impairment has been described in people with bvFTD, little is currently known about the extent or type of linguistic difficulties that occur, particula...

The value of colour vision assessment in the understanding of ophthalmological and neurological disorders impairments cannot be underestimated. Here we discuss impairment of parallel retinocortical pathways in early stages of Parkinson's disease. The debate on the relative contribution of retinal vs. cortical mechanisms is also addressed concerning...

In spite of the appeal of using retinal markers as potential windows to study brain neurodevelopment and aging in health and disease, many challenges remain. Here we address the relative role of multimodal techniques in basic, translational and clinical research, in a set of neurodevelopmental and neurodegenerative disorders differentially affectin...

Purpose: Neural plasticity upon visual loss remains a very controversial phenomenon. We asked how the changes in peripheral visual input in adult Retinitis Pigmentosa patients would impact the stability versus plasticity of neuronal population receptive fields in early visual areas. Methods: A total of 37 participants were recruited. The Retinitis...

Purpose: This study aimed to investigate whether texture from optical coherence tomography (OCT) can address Alzheimer's disease (AD)-related changes in the retina by evaluating differences to the wild-type (WT) control group over time. Methods: The study included OCT data of WT mice and its age-matched transgenic mice of AD (3xTg-AD). Animals were...

The retina is increasingly being recognized as a window to brain neurodevelopment, ageing and degeneration. This non-invasive window to vascular and neural function has shown promise to modify disease diagnosis, follow-up and management. Here we review imaging evidence reflecting critical interactions between ageing, systemic disorders (diabetes) a...

Background: Investigation of neural response patterns along the entire network of functionally defined object recognition ventral stream regions in Alzheimer's disease (AD) is surprisingly lacking. Objective: We aimed to investigate putative functional reorganization along a wide-ranging network of known regions in the ventral visual stream in m...