Significance Statement Forgetting plays an essential role in memory function as both excessive and insufficient forgetting are related to profound disruptions of mental health. Our results provide preliminary evidence that the forgetting of sensitization in Aplysia is a regulated process that can be delayed by blocking arachidonic acid production. This work contributes to ongoing efforts to understand the neurobiology of forgetting.
]]>Significance Statement The Science Education for the Youth (SEFTY) program at UNLV successfully engaged 117 diverse high school students in neuroscience-based experiential learning, demonstrating the viability of in-person education during a pandemic. Significant improvements in science proficiency (20.3% increase) underscore the program's effectiveness in fostering academic excellence and diversity. This initiative potentially serves as a model for maintaining high-quality, inclusive science education in challenging times.
]]>Significance statement AMPA-type glutamate receptors are pivotal in synaptic transmission and plasticity, and their dysregulation is linked to neurological conditions and age-related cognitive decline. Despite their importance, the mechanisms regulating these receptors are not fully understood. In this study, we examined age-related changes in the AMPA-type glutamate receptor GLR-1 in Caenorhabditis elegans and assessed its impact on short-term memory decline. Our data show a significant reduction in both the abundance and local turnover of total and membrane-bound GLR-1 receptors as animals age. This decline closely correlates with decreased performance in aversive olfactory memory tasks in older animals. Importantly, inhibiting GLR-1 degradation effectively mitigates short-term memory decline in aged animals.
]]>Significance Statement Effective navigation depends on efficient utilization of various spatial cues within an environment. Understanding how neural representations derived from distinct spatial cues relate — whether they are cue-specific or cue-independent — is paramount. The current study employed desktop virtual reality, ultra-high-field fMRI, and a novel repetition suppression paradigm that contrasted landmarks and self-motion cues. While not replicating our previous finding of positional coding in the entorhinal cortex under the new experimental conditions, the current study reveals cue-specific allocentric neural representations of spatial locations in the human retrosplenial cortex for the first time. This finding enriches our understanding of how the brain processes diverse sources of spatial information for cognitive map formation.
]]>Significance Statement In the human memory circuit, the hippocampus is considered as a structure with relatively late activation, associated to the retrieval of elaborate memories. However, in most electrophysiological studies, it is characterized by the activity of a single contact, which may not represent the entire dynamics of this structure. Here, we combined intracerebral recordings with independent component analysis to separate the activity from two different neural sources generated in the hippocampus. We analyzed the responses of both sources during the recognition of old and new images. Our results reveal new dynamics associated to different neuronal sources within the hippocampus, with recognition memory occurring much faster than previously reported.
]]>Significance Statement The inferior colliculus (IC) integrates multiple inputs to analyze information about social vocalizations. In mice, we show that the most common type of social vocalization, the ultrasonic vocalization or USV, was poorly represented in IC compared to lower frequency vocalizations. For most neurons, responses to vocal signals occurred only when frequency response areas overlapped with vocalization spectra. These results highlight a paradox of USV processing in some rodent auditory systems: although USVs are the most abundant social vocalization, their representation and representation of corresponding frequencies is less than lower frequency social vocalizations. These results suggest that USVs with lower frequency elements (<50 kHz)—associated with increased emotional intensity—will engage a larger population of neurons in the mouse auditory system.
]]>Significance statement Obsessive compulsive disorder is a debilitating psychiatric disorder with inadequate treatment options. The gene SLC1A1 has been associated with OCD in humans, and studies in rodents have shown alterations in OCD-relevant behavior and neural activity in mice with increased Slc1a1 expression. We created a novel mouse model with reversible forebrain overexpression of Slc1a1 and found that these mice show increased behavioral response to amphetamine. Using an unbiased machine classifier we found differences in clusters of amphetamine-induced behaviors in Slc1a1-overexpressing mice. In addition, Slc1a1-overexpressing mice showed increased neuronal activation in D1-expressing cells in ventromedial striatum following amphetamine administration. These results provide information about the role of Slc1a1 in repetitive behaviors and may contribute to novel treatments going forward.
]]>Significance Statement USVs in rodents have been widely used as experimental models to study neural mechanisms and deficits in social, emotional, and motor functions in mammals. However, the involvement of the motor cortex has not yet been fully characterized. In this study, we investigated the neural activity around USVs across the rat motor cortex and its relationship with projections to the PAG, which plays a central role in producing USV. The results demonstrated strong involvement of the motor cortex in USVs at both neuronal and circuit levels. This study provides a basis for future studies examining the cortical control of USVs using genetic and physiological manipulations.
]]>Significance Statement It remains unclear whether the proposed functional role of alpha and beta oscillations in perceptual function is generalizable to higher-level cognitive processes. We constructed a novel rule-switching paradigm involving speech comprehension and word production. We found that alpha power is modulated by cognitive load and is linked to task performance, potentially by regulating inhibition in brain regions linked to lexical retrieval. Additionally, the spatiotemporal pattern of beta activity differed between two distinct task rules, in line with the proposed role of beta in encoding of distinct categories and recruitment of respective neural networks. We offer experimental findings that support the view of a domain-general role of oscillations across the hierarchy of cognitive functions, from low-level sensory operations to high-level processes.
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