Vestibular research is essential for understanding and treating disorders such as vertigo and Meniere's disease. The vestibulo-ocular reflex (VOR) is a key method for assessing vestibular function and an essential tool for diagnosing vertigo. Traditionally, the VOR comprises angular VOR (aVOR) and translational VOR (tVOR), which originate from the vestibular semicircular canals (SCCs) and otolith organs, respectively. VOR consists of both fast-phase and slow-phase eye movements, which functionally interact to contribute to gaze control. However, to calculate the gain and phase parameters of the VOR, it is common practice to exclude fast-phase information superimposed on slow-phase eye movements. As a result, the information contained in the fast phase has not been fully utilized. OVAR is primarily used to evaluate otolith function, as there is no SCC input during its steady state. It is widely accepted that fast-phase nystagmus (FPN) during OVAR is generated by periodic otolith inputs via the central vesti...

Early psychosis (EP) is a critical period for psychotic disorders during which the brain undergoes rapid and significant functional and structural changes ( [Shinn et al., 2017][1]). The Human Connectome Project (HCP) is a global effort to map the human brain's connectivity in health and disease. Here we focus on HCP-EP subjects (i.e., those within 5 years of the initial psychotic episode) to determine macro- and microstructural alterations in EP (HCP-EP sample, n  = 179: EP, n  = 123, controls, n  = 56) and their association with clinical outcomes (i.e., symptoms severity) in HCP-EP. We carried out analyses of deformation-based morphometry (DBM), scalar indices from the diffusion tensor imaging (DTI), and tract-based spatial statistics (TBSS). Lastly, we conducted correlation analyses focused on the midbrain (DBM and DTI) to examine associations between its structure and clinical symptoms. Our results show that the midbrain displays robust alteration in its structure (DBM and DTI) in the voxel-based analy...

Human brain banks are essential for studying a wide variety of neurological and neurodegenerative diseases, yet the variability in postmortem interval (PMI)—the time from death to tissue preservation—poses significant challenges due to rapid cellular decomposition, protein alterations, and RNA degradation. Furthermore, the postmortem transcriptomic alterations occurring within distinct cell types are poorly understood. In this study, we analyzed the effect of a 3 h postmortem interval on single-nucleus RNA signatures in the brains of wild-type (WT) and PS19 mice, a common model of tauopathy. We observed that basic quality control metrics (such as the number of genes and reads per cell), total nuclei counts, and RNA integrity number (RINe) remained consistent across all samples, regardless of PMI or genotype. However, a 3 h PMI diminished the number of genes differentially expressed between PS19 and WT mice, suggesting an impact of delayed processing on the detection of disease-specific transcriptomic signa...

Electrophysiology recordings from the brain using laminar multielectrode arrays allow researchers to measure the activity of many neurons simultaneously. However, laminar microelectrode arrays move relative to their surrounding neural tissue for a variety of reasons, such as pulsation, changes in intracranial pressure, and decompression of neural tissue after insertion. Inferring and correcting for this motion stabilizes the recording and is critical to identify and track single neurons across time. Such motion correction is a preprocessing step of standard spike-sorting methods. However, estimating motion robustly and accurately in electrophysiology recordings is challenging due to the stochasticity of the neural data. To tackle this problem, we introduce MEDiCINe ( M otion E stimation by Di stributional C ontrastive I nference for Ne urophysiology), a novel motion estimation method. We show that MEDiCINe outperforms existing motion estimation methods on an extensive suite of simulated neurophysiology rec...

Mitral cells (MCs) and tufted cells (TCs) in the olfactory bulb (OB) act as an input convergence hub and transmit information to higher olfactory areas. Since first characterized, they have been classed as distinct projection neurons based on size and location: laminarly arranged MCs with a diameter larger than 20 µm in the mitral layer (ML) and smaller TCs spread across both the ML and external plexiform layers (EPL). Recent in vivo work has shown that these neurons encode complementary olfactory information, akin to parallel channels in other sensory systems. Yet, many ex vivo studies still collapse them into a single class, mitral/tufted, when describing their physiological properties and impact on circuit function. Using immunohistochemistry and whole-cell patch–clamp electrophysiology in fixed or acute slices from adult mice, we attempted to align in vivo and ex vivo data and test a soma size-based classifier of bulbar projection neurons using passive and intrinsic firing properties. We found that the...

How humans achieve such a high degree of prosocial behavior is a subject of considerable interest. Exploration of the neural foundations of human prosociality has garnered significant attention in recent decades. Nevertheless, the neural mechanisms underlying human prosociality remain to be elucidated. To address this knowledge gap, we analyzed multimodal brain imaging data and data from 15 economic games. The results revealed several significant associations between brain characteristics and prosocial behavior, including stronger interhemispheric connectivity and larger corpus callosum volume. Greater functional segregation and integration, alongside fewer myelin maps combined with a thicker cortex, were linked to prosocial behavior, particularly within the social brain regions. The current study demonstrates that these metrics serve as brain markers of human prosocial behavior and provides novel insights into the structural and functional brain basis of human prosocial behavior.

Delayed motor development is an early clinical sign of fetal alcohol spectrum disorders. However, changes at the neural circuit level that underlie early motor differences are underexplored. The striatum, the principal input nucleus of the basal ganglia, plays an important role in motor learning in adult animals, and the maturation of the striatal circuit has been associated with the development of early motor behaviors. Here, we briefly exposed pregnant C57BL/6 dams to ethanol (5% w/w) in a liquid diet on embryonic days 13.5–16.5 and assessed the mouse progeny using a series of nine brief motor behavior tasks on postnatal days 2–14. Live brain slices were then obtained from behaviorally tested mice for whole-cell voltage- and current-clamp electrophysiology to assess GABAergic/glutamatergic synaptic activity and passive/active properties in two populations of striatal neurons: GABAergic interneurons and spiny striatal projection neurons. Electrophysiologically recorded spiny striatal projection neurons we...

Evolutionary pressures adapted insect chemosensation to their respective physiological needs and tasks in their ecological niches. Solitary nocturnal moths rely on their acute olfactory sense to find mates at night. Pheromones are detected with maximized sensitivity and high temporal resolution through mechanisms that are mostly unknown. While the inverse topology of insect olfactory receptors and heteromerization with the olfactory receptor coreceptor suggest ionotropic transduction via odorant-gated receptor–ion channel complexes, contradictory data propose amplifying G-protein–coupled transduction. Here, we used in vivo tip-recordings of pheromone-sensitive sensilla of male Manduca sexta hawkmoths at specific times of day (rest vs activity). Since the olfactory receptor neurons distinguish signal parameters in three consecutive temporal windows of their pheromone response (phasic; tonic; late, long-lasting), respective response parameters were analyzed separately. Disruption of G-protein–coupled transdu...

Maintenance of normal structure of the enteric nervous system (ENS), which regulates key gastrointestinal functions, requires robust homeostatic mechanisms, since by virtue of its location within the gut wall, the ENS is subject to constant mechanical, chemical, and biological stressors. Using transgenic and thymidine analog-based experiments, we previously discovered that neuronal turnover—where continual neurogenesis offsets ongoing neuronal loss at steady state—represents one such mechanism. Although other studies confirmed that neuronal death continues into adulthood in the myenteric plexus of the ENS, the complicated nature of thymidine analog presents challenges in substantiating the occurrence of adult neurogenesis. Therefore, it is vital to employ alternative, well-recognized techniques to substantiate the existence of adult enteric neurogenesis in the healthy gut. Here, by using established methods of assessing nuclear DNA content and detecting known mitotic marker phosphor-histone H3 (pH3) in Hu+...

In models of visual spatial attention control, it is commonly held that top–down control signals originate in the dorsal attention network, propagating to the visual cortex to modulate baseline neural activity and bias sensory processing. However, the precise distribution of these top–down influences across different levels of the visual hierarchy is debated. In addition, it is unclear whether these baseline neural activity changes translate into improved performance. We analyzed attention-related baseline activity during the anticipatory period of a voluntary spatial attention task, using two independent functional magnetic resonance imaging datasets and two analytic approaches. First, as in prior studies, univariate analysis showed that covert attention significantly enhanced baseline neural activity in higher-order visual areas contralateral to the attended visual hemifield, while effects in lower-order visual areas (e.g., V1) were weaker and more variable. Second, in contrast, multivariate pattern anal...