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 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 soundscape. P...

The prepositus hypoglossi nucleus (PHN), involved in horizontal gaze control, contributes to this function via cooperation with the vestibulocerebellum (VC). Furthermore, some PHN neurons have been observed to project to cerebellar regions outside the VC. We previously reported a neuronal population in the ventral caudal PHN that projects to lobules III–V of the anterior vermis or to the cerebellar hemispheric crus. Because the properties of these neurons have not been clarified, this study aimed to determine their localization, projections, and electrophysiological and morphological characteristics in male rats. Tracing experiments revealed that these neurons were clustered within the ventral caudal PHN, approximately between the bregma −12.72 and −12.00 mm, and did not project to the uvula/nodulus (UN), which is part of the VC. Whole-cell recordings and morphological experiments revealed that these PHN neurons exhibited high input capacitance, low input resistance, low-frequency firing, prominent voltage...

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 such drift, 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...

Animal behavior is crucial for understanding both normal brain function and dysfunction. To facilitate behavior analysis of mice within their home environments, we developed DeepEthoProfile, an open-source software powered by a deep convolutional neural network for efficient behavior classification. DeepEthoProfile requires no spatial cues for either training or processing and is designed to perform reliably under real laboratory conditions, tolerating variations in lighting and cage bedding. For data collection, we introduce EthoProfiler, a mobile cage rack system capable of simultaneously recording up to 10 singly housed mice. We used 36 h of manually annotated video data sampled in 5 min clips from a 48 h video database of 10 mice. This published dataset provides a reference that can facilitate further research. DeepEthoProfile achieved an overall classification accuracy of over 83%, comparable with human-level accuracy. The model also performed on par with other state-of-the-art solutions on another pu...

Advances in in vivo Ca2+ imaging using miniature microscopes have enabled researchers to study single-neuron activity in freely moving animals. Tools such as Minian and CalmAn have been developed to convert Ca2+ visual signals to numerical data, collectively referred to as CalV2N. However, substantial challenges remain in analyzing the large datasets generated by CalV2N, particularly in integrating data streams, evaluating CalV2N output quality, and reliably and efficiently identifying Ca2+ transients. In this study, we introduce CalTrig, an open-source graphical user interface (GUI) tool designed to address these challenges at the post-CalV2N stage of data processing collected from C57BL/6J mice. CalTrig integrates multiple data streams, including Ca2+ imaging, neuronal footprints, Ca2+ traces, and behavioral tracking, and offers capabilities for evaluating the quality of CalV2N outputs. It enables synchronized visualization and efficient Ca2+ transient identification. We evaluated four machine learning m...

The endocannabinoid (eCB) signaling system is robustly expressed in the cerebellum from embryonic developmental stages to adulthood. It plays a key role in regulating cerebellar synaptic plasticity and excitability, suggesting that impaired eCB signaling could lead to deficits in cerebellar adjustments of ongoing behaviors and cerebellar learning. Indeed, human mutations in DAGLα are associated with neurodevelopmental disorders. In this study, we show that selective deletion of the eCB synthesizing enzyme diacylglycerol lipase alpha (Daglα) from mouse cerebellar Purkinje cells (PCs) alters motor and social behaviors, disrupts short-term synaptic plasticity in both excitatory and inhibitory synapses, and reduces PC activity during social exploration. Our results provide the first evidence for cerebellar-specific eCB regulation of social behaviors and implicate eCB regulation of synaptic plasticity and PC activity as the neural substrates contributing to these deficits.

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 Caenorhabditis 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 ...

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...

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 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 of GDE2 in mouse hippocampal function are not known. Here, we show that GDE2 is expressed in pre- and postsynaptic compartments along apical dendrites in hippocampal CA1 cells. Gde2 KO CA1 cells showed increased dendritic length and complexity and increased numbers ...

Previous research suggests that stress predisposes individuals to develop substance use disorders by disrupting the brain processing of rewards. Yet, how stressful experiences disrupt the brain processing of reward-related cues at the neuronal level is poorly understood. Intermittent social defeat (ISD) is a stress animal model that increases reward-seeking behavior, drug self-administration, and choice impulsivity up to several weeks after stress. We tested the hypothesis that ISD disrupts the neuronal encoding of reward cues in key areas of the brain that regulate reward-seeking. We examined in vivo neuronal dynamics in response to reward cues in the dorsal medial prefrontal cortex (dmPFC) and the ventral tegmental area (VTA) simultaneously, and longitudinally, in control and stressed Long–Evans male rats during a discriminative stimulus reward-seeking task. In the dmPFC, ISD decreased cue-evoked neuronal activity 1 and 15 d after stress, which indicates a long-term degradation of outcome anticipation-re...