Auditory-evoked EEG signals contain rich temporal and cognitive features that reflect both the identity of individuals and their neural response to external stimuli. Traditional unimodal approaches often fail to fully leverage this multidimensional information fully, limiting their effectiveness in real-world biometric and neurocognitive applications. This study aims to develop a unified deep learning model capable of jointly performing biometric identification, auditory stimulus language classification, and device modality recognition, thereby exploiting both physiological and cognitive dimensions of auditory-evoked EEG. We introduce TriNet-MTL (Triple-Task Neural Transformer for Multitask Learning), a multi-branch deep learning framework composed of a shared temporal encoder and a transformer-based sequence modeling unit, trained and validated on auditory-evoked EEG data from 20 human participants (16 males and 4 females). The architecture is designed to simultaneously learn task-specific features via th...

Neurite outgrowth is essential for neural circuit formation and is tightly regulated by secreted factors and their receptors. The secreted extracellular domain of the amyloid precursor protein (sAPPα) has been shown to modulate neurite outgrowth. Recently, the gamma amino butyric acid receptor type-B subunit 1a (GABABR1a) was identified as an sAPPα binding partner that mediates its effects on synaptic transmission. Here, we investigated whether this interaction also regulates neurite outgrowth. In mouse primary hippocampal neurons of either sex, the GABABR agonist baclofen reduced axon length; whereas, its antagonist CGP54626 increased axon length in primary hippocampal neurons. Moreover, GABABR1a knockout increased axon length and abolished the effect of baclofen. Application of sAPPα reduced axon length, an effect that required the presence of both GABABR1a and the extension domain of sAPPα, which mediates its binding to GABABR1a. Similarly, the APP 17mer peptide, which is sufficient to bind GABABR1a and...

Social cognition, central to emotional and cognitive well-being, is particularly vulnerable to aging, where impairments can lead to isolation and functional decline. Despite compelling evidence that altered social behavior is associated with cognitive decline and dementia risk, experimental strategies for testing causative links remain scarce. To address this gap, we aimed to establish a rat model for research on social neurocognitive aging. We conducted a large-scale behavioral study in 169 male young (6 months) and aged (24-25 months) Long-Evans rats. In order to explore potential relationships among aging outcomes, we first documented individual differences in a widely validated water maze test of hippocampal learning and memory. Sociability and social novelty were then evaluated in the same subjects using the three-chamber social interaction test. Aging induced a selective shift in social novelty preference, marked by a striking familiarity bias in a substantial subpopulation of old rats, while sociabi...

The transition to virtual conferences and poster presentations poses its own set of challenges, especially for those new to this format. Having recently participated in Neuroscience 2022, which was my first virtual presentation, I'm eager to share some insights and practical advice.

Magnetic resonance imaging (MRI) is a critical tool for translational neuroscience, but preclinical studies frequently rely on anesthesia, which alters neural activity and limits comparison with human studies. Awake rodent functional MRI (fMRI) enables investigation of brain function under physiologically relevant conditions; however, its implementation is constrained by the need for anesthesia during restraint setup. We developed and evaluated a restraint system and habituation protocol for awake rat fMRI. Ten rats were studied: an awake group and an anesthetized group (three males and two females per group). The protocol included head post implantation and an 11 d habituation period. T2-weighted anatomical and functional scans were acquired. Head motion and functional connectivity were analyzed using the RABIES pipeline and compared between groups. The modular 3D-printed restraint system developed can be assembled in under 5 min; eliminates the need for anesthesia, ear bars, and bite bars; and supports s...

Natural environments contain behaviorally relevant information along many stimulus dimensions, each of which sensory systems must encode in order to guide behaviors. For example, the mammalian visual cortex encodes features of visual scenes such as spatial information related to object identity and temporal information about the motion of those objects in space. In order to reliably encode these behaviorally relevant visual features, neural representations should be robust to changes in environmental conditions. Further, information about changes in environmental conditions, such as the luminance changes that occur over the course of a day, is also important for guiding behaviors. In this study, we asked whether mouse primary visual cortex (V1) jointly represents the spatial properties of visual stimuli along with changes in the mean luminance of the visual scene. We find that while V1 neurons, in mice of either sex, encode spatial aspects of visual information in an invariant manner across luminance condi...

Age-related vascular changes accompany or precede the development of Alzheimer's disease (AD) pathology. The comorbidity of AD and arterial stiffening suggests that vascular changes have a pathogenic role. Carotid artery mechanics and hemodynamics have been associated with age-related cognitive decline. However, the impact of hemodynamics and vascular mechanics on regional vulnerability within the brain has not been thoroughly explored. Compared with the arterial system, brain venous circulation in cognitive impairment is less understood despite the venous system's role in transport. To study vasculature impact on biochemistry in AD models, we must first establish the differences in vasculature mechanics and hemodynamics in a common AD model compared with healthy controls. With this baseline data, future studies on manipulating vasculature integrity in mice become feasible. Young and aged female 3xTg mice and age-matched controls were imaged using a combination of ultrasound and mass spectrometry. Wall she...

Microglia, resident immune sentinels in the brain, are crucial in responding to tissue damage, infection, damage signals like purines (ATP/ADP), and clearing cellular debris. It is currently unknown how microglial reactivity progresses and contributes to seizure development following Theiler's murine encephalomyelitis virus (TMEV) infection. Previously, it has been demonstrated that purinergic signaling in microglia is disrupted in the hippocampus of TMEV-infected mice. However, whether reactive cortical microglia also exhibit changes in purinergic signaling, cytokine levels, and purinergic receptors is unknown. Thus, we seek to evaluate region-based differences in microglial reactivity in the TMEV model. We employed a custom triple transgenic mouse line expressing tdTomato and GCaMP6f under a CX3CR1 Cre promoter and exogenously applied ATP/ADP to acute brain slice preparations from TMEV-infected mice and controls of either sex. Interestingly and in contrast to what is observed in the hippocampus, we found...

Nonrapid eye movement (NREM) sleep is characterized by the interaction of multiple oscillations essential for memory consolidation, alongside a dynamic arrhythmic 1/ f scale-free background that may also contribute to its functions. Recent spectral parametrization methods, such as fitting oscillation and one-and-over-F and irregular resampling auto-spectral analysis, enable the dissociation of rhythmic and arrhythmic components in the spectral domain; however, they do not resolve these processes in the time domain. Instantaneous measures of frequency, amplitude, and phase–amplitude coupling (PAC) are thus still confounded by fluctuations in arrhythmic activity. This limitation represents a pitfall for studies of NREM sleep relying on instantaneous estimates to investigate oscillatory coupling. To address this limitation, we introduce “Rhythms and Background” (RnB), a novel wavelet-based methodology designed to dynamically denoise time series data of arrhythmic interference. This enables the extraction of p...

Rigorous, statistically grounded experimental design is central to ethical and effective animal research. Foundational principles for statistically based Design of Experiments (DOE) were established over a century ago by Sir Ronald Fisher. They have since been augmented by modern computational tools that now enable researchers to implement designs that maximize scientific information and benefit while minimizing harms. However, many preclinical investigators are unfamiliar with formal DOE methods. Poorly designed experiments followed by inappropriate statistical analyses contribute to poor reproducibility, translational failure, and unnecessary animal use. This first paper in a three-part series introduces neuroscience researchers to the fundamentals of statistically based experimental design as a substitute for traditional two-group comparisons. Key components of a designed experiment are defined, along with the importance of correctly identifying experimental units to avoid pseudo-replication. Fisher's t...