Cuban Neuroscience Center

Several animal models of Alzheimer’s disease have been developed and tested for diagnostic and treatment purposes. [11C]PIB is the gold-standard radiotracer for the detection of Aβ plaque deposits, a hallmark of the disease. This study aimed to evaluate the in vivo detection of Aβ plaques using [11C]PIB microPET imaging across different animal models of Alzheimer’s disease. The study included 3xTg-AD transgenic mice, TgF344-AD transgenic rats and Aβ injection-based rat model. The results showed an age-related increase in [11C]PIB uptake in 3xTg-AD mice, particularly in the midbrain and thalamus. In TgF344-AD rats, differences were also observed compared to WT controls, with the highest values observed in the hippocampus and cortex. In the injection-based model, inoculated rats showed greater uptake in the injection site than SHAM animals. Across all microPET studies, [11C]PIB uptake was consistently higher in females than in their male counterparts. These findings support the value of transgenic and Aβ injection-based models in preclinical research on Aβ plaque deposition and highlight the importance of considering species, model type, sex, and age in experimental design.

Background Quantitative EEG (qEEG) provides objective, millisecond-resolution measures of brain dynamics. Despite decades of methodological advances, clinically relevant derived indices—spectral power ratios, cognitive-emotional state markers, and physiological parameters—are typically reported as raw values without the normative context required for individualized clinical inference. Objective To develop the first systematic age-dependent normative models for this family of derived qEEG indices using a multinational database, enabling probabilistic Z-score interpretation at the individual level and objective therapeutic monitoring. Methods Normative modeling was applied to the HarMNqEEG database (n = 1,564 neurologically healthy participants, ages 5–97, 9 countries, eyes-closed resting state). Electrode-level Spectral Normalization (ESN) removed inter-individual and inter-device amplitude variability while preserving the neurophysiological interpretability of each index. Age-dependent normative trajectories were estimated using Generalized Additive Models for Location, Scale, and Shape (GAMLSS) with P-splines on log(age), allowing conditional mean and variance to vary non-linearly across the lifespan. Results GAMLSS modeling revealed significant non-linear age-dependent trajectories for all indices. Slow-wave-dominated ratios showed steep decreases from childhood to early adulthood, consistent with cortical maturation; alpha-dominated indices increased during adolescence before stabilizing. ESN normalization yielded well-calibrated normative residuals across the full age range and across all nine recording devices. Conclusions These normative models enable principled, age-adjusted probabilistic inference at the individual level, bridging the historical gap between advanced qEEG methodology and routine clinical practice. The ESN strategy requires no knowledge of recording equipment, ensuring broad applicability. The framework provides an objective tool for monitoring neurophysiological change during therapeutic interventions.

Latin America and the Caribbean have a long-standing tradition in brain research characterized by unique regional features. However, the region faces significant hurdles in maintaining pace with the rapid global advances in Brain Sciences observed over the last few decades. The Latin America Brain Initiative (LATBrain) was established to integrate regional efforts and catalyze the interdisciplinary development of Brain Sciences. To support this mission, LATBrain conducted the first survey to assess the perceptions of researchers, students, and professionals regarding opportunities and systemic barriers in the field across Latin America and the Caribbean.Respondents identified notable strengths, including high academic achievement, creativity, and a robust capacity for collaboration. Conversely, critical concerns centered on the need for sustained funding, access to state-of-the-art technology, and specialized interdisciplinary training. Public interest was perceived to be primarily aligned with applied societal issues, such as neurodegenerative disorders and mental health. Furthermore, the survey highlighted how insufficient funding compromises infrastructure sustainability and the retention of promissory and top-tier researchers.Our findings underscore a critical need to refocus training to be more socially relevant and academically interdisciplinary. LATBrain is actively collaborating with partners across Latin America and the Caribbean to overcome these limitations by strengthening scientific integration and interdisciplinarity, promoting resource sharing, and advocating for the socio-economic importance of brain research. This strategic plan seeks to solidify the region’s position as a global leader in brain research

The paper presents a quantitative description of the torsional dynamics of a macromolecule using the trinucleotide repeat region in the ATXN2 gene as a model system. The analysis of the macromolecular dynamics is based on an angular model, the mechanical analogue of which is a chain of n linked pendulums (n is the number of base pairs) described by a system of ordinary differential equations for angular deviations. Particular attention is paid to how the number and location of CAA insertions in this region contribute to the formation of structurally unstable states and lead to replication and repair defects. The probability of additional open-state zones forming for various CAA insertion configurations and the effect of a viscous external environment on their stability, are calculated using angular and torsional DNA models. The results reveal the nonlinear nature of the CAA insertion effect and highlight the importance of their topology for the physical description of triplet-mediated genomic instability in the ATXN2 gene.

Accumulating evidence indicates that repetitive transcranial magnetic stimulation (rTMS) outcomes are state-dependent, with ongoing emotional states influencing neuromodulatory effects. However, how emotional context during stimulation influences subsequent brain functional state organization remains unclear. A total of 99 healthy participants were recruited in this study and allocated to one of three groups: active rTMS with sad film viewing (sad group), active rTMS with neutral film viewing (neutral group), or sham rTMS with sad film viewing (sham group). We combined rTMS during emotional film viewing with co-activation pattern (CAP) analysis to investigate the potential state-dependent effects of rTMS on brain dynamics. The fraction of time, resilience, and transition probabilities of CAPs were calculated to characterize brain dynamics. Four recurring CAPs were identified in this study. Relative to the sham group, participants following stimulation during the sad condition exhibited increased engagement of CAP 2, characterized by deactivations in the frontoparietal network and co-activations of the visual and somatomotor networks, along with decreased engagement of CAP 4, characterized by deactivations in the default mode network and co-activations of the somatomotor and salience networks. In contrast, the neutral condition exhibited attenuated effects. Furthermore, the change in transition probability from CAP 2 to CAP 3 was significantly greater in the sad condition than in the neutral condition. Together, these findings indicate that the effects of rTMS on brain dynamics may be modulated by the emotional context during stimulation. This work offers novel insights into the state-dependent modulation by rTMS and may help inform the optimization of therapeutic outcomes for rTMS interventions.