A truncated form of Xenopus E-cadherin (deltaE-cad) comprising the cytoplasmic and transmembrane domains was overexpressed generating a dominant negative mutation in the urodelan amphibian embryo Pleurodeles waltl. deltaE-cad mRNA and rhodamine-lysinated-dextran (RLDx) cell lineage tracer were microinjected into 32-cell stage blastomeres which contribute principally to the notochord and central nervous system. deltaE-cad expression causes defects in forebrain and hindbrain formation coupled with the development of supernumerary vesicles. Duplication of the notochord also occurs due to the retardation of medial cell intercalation with correlated duplications of spinal cord and somites. These results emphasize the role of cadherins in mediating cell-cell adhesion in early amphibian embryogenesis. They extend to Pleurodeles the observations made in Xenopus, illustrating that despite differences in morphogenetic processes, the molecular mechanisms are conserved in these two species.
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http://dx.doi.org/10.1002/(SICI)1097-0177(199811)213:3<248::AID-AJA2>3.0.CO;2-F | DOI Listing |
Adv Sci (Weinh)
January 2025
Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
Fragile X syndrome (FXS) is an inherited neurodevelopmental disorder characterized by a range of clinical manifestations with no effective treatment strategy to date. Here, transplantation of GABAergic precursor cells from the medial ganglionic eminence (MGE) is demonstrated to significantly improve cognitive performance in Fmr1 knockout (KO) mice. Within the hippocampus of Fmr1-KO mice, MGE-derived cells from wild-type donor mice survive, migrate, differentiate into functionally mature interneurons, and form inhibitory synaptic connections with host pyramidal neurons.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Neuroscience, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
Homeostatic sleep regulation is essential for optimizing the amount and timing of sleep for its revitalizing function, but the mechanism underlying sleep homeostasis remains poorly understood. Here, we show that optogenetic activation of locus coeruleus (LC) noradrenergic neurons immediately increased sleep propensity following a transient wakefulness, contrasting with many other arousal-promoting neurons whose activation induces sustained wakefulness. Fiber photometry showed that repeated optogenetic or sensory stimulation caused a rapid reduction of calcium activity in LC neurons and steep declines in noradrenaline/norepinephrine (NE) release in both the LC and medial prefrontal cortex (mPFC).
View Article and Find Full Text PDFCell Rep
January 2025
Centre for Systems Neuroscience, University of Leicester, Leicester, UK; Hospital Del Mar Medical Research Institute (IMIM), Barcelona, Spain; Institució Catalana de Recerca I Estudis Avançats (ICREA), Barcelona, Spain; Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address:
In subjects implanted with intracranial electrodes, we use two different stories involving the same person (or place) to evaluate whether and to what extent context modulates human single-neuron responses. Nearly all neurons (97% during encoding and 100% during recall) initially responding to a person/place do not modulate their response with context. Likewise, nearly none (<1%) of the initially non-responsive neurons show conjunctive coding, responding to particular persons/places in a particular context during the tasks.
View Article and Find Full Text PDFAlzheimers Dement
January 2025
Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Sanya, China.
Introduction: Alzheimer's disease (AD) is the most common neurodegenerative disease, characterized by damage to cortical circuits. However, the mechanisms underlying AD-associated changes in long-range circuits remain poorly understood.
Methods: In this study, we used viral tracing and fluorescence micro-optical sectioning tomography (fMOST) imaging to investigate whole-brain changes in the input circuit of the frontal cortex of 5×FAD mice.
Commun Biol
January 2025
Neuroscience & Mental Health, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
The prefrontal cortex (PFC) is vital for higher cognitive functions and displays neuronal heterogeneity, with neuronal activity varying significantly across individual neurons. Using calcium imaging in the medial PFC (mPFC) of mice, we investigate whether differences in degree centrality-a measure of connectivity strength within local circuits-could explain this neuronal diversity and its functional implications. In young adults, neurons with high degree centrality, inferred from resting-state activity, exhibit reliable and stable action-plan selectivity during memory-guided tasks, suggesting that connectivity strength is closely linked to functional heterogeneity.
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