Developing granule cells (GCs) of the adult dentate gyrus undergo a critical period of enhanced activity and synaptic plasticity before becoming mature. The impact of developing GCs on the activity of preexisting dentate circuits remains unknown. Here we combine optogenetics, acute slice electrophysiology, and in vivo chemogenetics to activate GCs at different stages of maturation to study the recruitment of local target networks. We show that immature (4-week-old) GCs can efficiently drive distal CA3 targets but poorly activate proximal interneurons responsible for feedback inhibition (FBI). As new GCs transition toward maturity, they reliably recruit GABAergic feedback loops that restrict spiking of neighbor GCs, a mechanism that would promote sparse coding. Such inhibitory loop impinges only weakly in new cohorts of young GCs. A computational model reveals that the delayed coupling of new GCs to FBI could be crucial to achieve a fine-grain representation of novel inputs in the dentate gyrus.
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http://dx.doi.org/10.1016/j.neuron.2014.11.023 | DOI Listing |
Neuro Oncol
December 2024
Center For Neuro-Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, USA.
Isocitrate dehydrogenase (IDH)-mutant gliomas are the most common malignant primary brain tumors in young adults. This condition imposes a substantial burden on patients and their caregivers, marked by neurocognitive deficits and high mortality rates due to tumor progression, coupled with significant morbidity from current treatment modalities. Although surgery, radiation therapy, and chemotherapy improve survival, these treatments can adversely affect cognitive function, quality of life, finances, employment status, and overall independence.
View Article and Find Full Text PDFJ Pineal Res
January 2025
Department of Integrated Biology and Physiology, University of Minnesota, Minneapolis, Minnesota, USA.
Light environment in the Arctic differs widely with the seasons. Studies of relationships between objectively measured circadian phase and amplitude of light exposure and melatonin in community-dwelling Arctic residents are lacking. This investigation combines cross-sectional (n = 24-62) and longitudinal (n = 13-27) data from week-long actigraphy (with light sensor), 24-h salivary melatonin profiles, and proxies of metabolic health.
View Article and Find Full Text PDFJ Family Med Prim Care
November 2024
Department of OBG, AIIMS, Bhubaneswar, Odisha, India.
The occurrence of spontaneous bladder rupture during labor or the postpartum period after an uncomplicated vaginal delivery is exceedingly uncommon. However, we encountered a case involving spontaneous bladder rupture, which resulted in the development of localized fluid collections in the abdomen after an uncomplicated vaginal delivery. In this instance, the absence of typical peritonitis symptoms, such as abdominal pain or tenderness, and the lack of typical urological symptoms, including haematuria, dysuria, and anuria, coupled with the absence of clinical manifestations of puerperal sepsis, the absence of microbial presence in the ascitic fluid, and the patient's symptomatic amelioration following antibiotic therapy, contributed to a delay in identifying the bladder rupture.
View Article and Find Full Text PDFEnviron Health (Wash)
December 2024
Department of Occupational Health and Environmental Health, School of Public Health, Capital Medical University, 100069 Beijing, China.
Exposure to metals may potentially impact cognitive health in the elderly; however, the evidence remains ambiguous. The specific role of serum folate in this relationship is also unclear. We aimed to evaluate the individual and joint impact of metals on cognition in the elderly from the United States and explore the potential mediating effect of serum folate.
View Article and Find Full Text PDFJ Magn Reson
December 2024
Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181, UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France. Electronic address:
The two-dimensional (2D) refocused INADEQUATE NMR experiment, which correlates double-quantum (DQ) and single-quantum (SQ) coherences, is widely used to probe the chemical connectivities in solids. Nevertheless, the multiplets along the F dimension reduce the resolution and sensitivity of this experiment. The Composite-Refocusing (CR) technique with two excitation pulses has been proposed to suppress these multiplets in 2D INADEQUATE spectra of liquids.
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