Hippocampal synaptic activity is tightly regulated to ensure appropriate synaptic function and plasticity, which are important for critical cognitive processes such as learning and memory. Altered hippocampal synaptic function can lead to cognitive and behavioral deficits observed in neurodegenerative diseases such as Alzheimer’s Disease (AD), necessitating a deeper fundamental understanding of hippocampal synaptic control mechanisms. Glycerophosphodiester phosphodiesterase 2 (GDE2 or GDPD5) is a surface transmembrane enzyme that cleaves the glycosylphosphatidylinositol (GPI) anchor that tethers some proteins to the membrane. Mice lacking GDE2 ( Gde2 KO) display behavioral deficits in learning and memory that are hippocampal-dependent. However, roles for GDE2 in mouse hippocampal function are not known. Here, we show that GDE2 is expressed in pre- and post-synaptic compartments along apical dendrites in hippocampal CA1 cells. Gde2 KO CA1 cells showed increased dendritic length and complexity and increased ...

Nowadays, undergraduate institutions — and students — expect a lot from faculty: a joy in fostering student success, an ability to explain complex research projects at an undergraduate level, a capacity to train the next generation of scientists on a modest budget and with shared equipment, and most of all, passion for both teaching and research.

It has long been hypothesized that the nervous system uses the direction of gravity to align the various sensory systems when interacting with the external world. In line with this hypothesis, systematic drift in hand-path orientation was recently observed during targeted arm motions performed with eyes closed in weightlessness or, on Earth, for longitudinal movements in a supine posture. No such drift was observed in upright posture on Earth. But the precise conditions under which participants exhibit, and the factors that influence the magnitude of the drift, are not yet known. The objective of our study was to investigate if the upright posture, by virtue of being at a biomechanical singularity induced by the force of gravity, represents a unique condition in which drift in hand-path orientation is prevented. Human participants (male and female) performed sequences of repeated point-to-point arm movements between two visual targets aligned with the longitudinal body axis, first with eyes open, then with...

Hippocampal sharp-wave ripples (SWRs) are critical events implicated in memory consolidation, planning, and the reactivation of recent experiences. Under freely moving conditions, a well-established dichotomy exists: hippocampal networks predominantly generate theta oscillations during periods of reward pursuit (preparatory behaviors) and exhibit pronounced SWR activity once the reward is achieved (consummatory behaviors). Here, it was examined how SWRs are modulated by reward delivery and small movements in head-fixed rats. Contrary to the canonical view established in freely moving settings, the results revealed that the dominant and more enduring effect was a sustained suppression of SWR activity immediately following water delivery. Moreover, even minor, localized movements (such as whisking or body adjustments) decreased SWR occurrence, demonstrating that hippocampal ripple generation is highly sensitive to motor engagement, irrespective of reward timing. Such movement-induced suppression of ripples p...

Accurate perception of the direction of gravity relies on the integration of multisensory information, particularly from the visual and vestibular systems, within the brain. Although a recent study of patients with cerebellar degeneration suggested a cerebellar role in visuo-vestibular interaction in the perception of gravitational direction, direct evidence remains limited. To address this gap, we conducted two experiments with 42 healthy participants to evaluate the impact of repetitive 1-Hz transcranial magnetic stimulation (rTMS) over the posterior cerebellar vermis on visual dependency, quantified by the subjective visual vertical bias induced by rotating optokinetic stimulation (OKS). Electric field simulations in high-resolution generic head models were used to ensure focal stimulation of the cerebellum at the group level. The results demonstrated that the rTMS applied to the vermis significantly attenuated the OKS-induced shift in visual vertical (SVV) bias. This effect was not observed when stimul...

Neuroimaging data reveal that a functional locus coeruleus-noradrenaline (LC-NA) system is critical in maintaining cognitive performance during aging. However, older adults show reduced LC integrity and altered functional connectivity, demonstrating both structural declines and dysfunction. The LC-NA system mediates mechanisms of attention processing and eye tracking studies have shown that older adults are slower and more distractible compared with young adults in visual search tasks. Prior studies have shown that mindfulness meditation modulates LC noradrenergic activity, increases gray matter volume in the brainstem, and improves attentional control. Thus, in a preregistered longitudinal study, we investigated whether thirty days of guided mindfulness meditation using a mobile application improved attentional control measured with eye movements. We hypothesized that older adults would show greater benefits from the mindfulness intervention compared with young adults. In two oculomotor search tasks, we i...

In everyday life, ambient sounds can disrupt our concentration, interfere with task performance, and contribute to mental fatigue. Even when not actively attended to, salient or changing sounds in the environment can involuntarily divert attention. Understanding how the brain responds to these real-world auditory distractions is essential for evaluating the cognitive consequences of environmental noise. In this study, we recorded electroencephalography (EEG) while participants performed different tasks during prolonged exposure to a complex urban soundscape. We identified naturally occurring, acoustically salient events and analyzed the corresponding event-related potentials (ERPs). Auditory spectral novelty reliably elicited a P3a response (250–350 ms), reflecting robust attentional capture by novel environmental sounds. In contrast, the Reorienting Negativity (RON) window (450–600 ms) showed no consistent modulation, possibly due to the continuous and largely behaviorally irrelevant nature of the soundsc...

Neural circuits that consolidate sensory cues are essential for neurological functioning. Neural circuits that perform sensory integration can vary greatly because the sensory processing regions of the brain employ various neural motifs. Here, we investigate a neural circuit that mediates the response to conflicting stimuli in C. elegans . We concurrently expose animals to an aversive dispersal pheromone, osas#9, and an attractive bacterial extract. While worms usually avoid osas#9 alone, they suppress this avoidance behavior in the presence of a bacterial extract. Loss-of-function mutants and cell-specific rescues reveal that signaling from the ADF and NSM neurons is essential for bacterial extract-induced osas#9 avoidance attenuation. The inhibitory serotonin receptor, MOD-1, which is widely expressed on interneurons and motor neurons, is required for this sensory integration, suggesting that serotonin acts in an inhibitory manner. By performing calcium imaging on the ADF neurons in synaptic signaling ( ...

Microglia, discovered in 1919 by Pío del Río-Hortega, turned 100 years old in 2019. For a long time, microglial research has been hindered by the misconception that these cells solely functioned as macrophages involved in the neuroinflammatory response. However, over the last few decades, there have been a flourish of unexpected discoveries of microglial functions, from synaptic remodeling and establishment of brain connectivity, to modulation of neurogenic niches, myelination, and blood-brain barrier maintenance.

We all have learned stereotypes that unconsciously influence how we see ourselves and others. Like perceptual illusions, some biases persist even once we are aware of them. Implicit bias impacts diverse scientific communities, ultimately limiting the potential of neuroscientists and inhibiting discovery.