Connexins are essential for the contribution of latent progenitors to healing after spinal cord injury.

October 27, 2026| Source: Proceedings of the National Academy of Sciences of the United States of America

Gap junctions are important regulators of the biology of neural stem cells. Both in vertebrates with regenerative abilities and neonatal rodents, ependymal cells communicate via connexin (Cx) 43 and Cx26. Gap junction coupling and Cx26 are down-regulated as the ependyma becomes quiescent in adulthood, but injury overrules this developmental down-regulation suggesting a role for Cx signaling in the reactivation of ependymal cells. However, direct evidence of the involvement of these Cxs in the reactivation of the ependymal stem cell niche is lacking. Here, we aim to explore the role of Cx26 and Cx43 in the response of ependymal cells to injury by means of specific genetic deletion. We find that Cx26 is critical for the proliferative response of ependymal cells to injury. The reduced response of ependymal cells by Cx26 deletion increased the extension of the lesion because of impaired healing resulting from a weak contribution of the ependymal stem cell niche. On the other hand, Cx43-via gap junction coupling and hemichannels-plays a key role in the communication of Ca 2+ signals between ependymal cells induced by activation of P2X7 receptors. Our data show that Cxs are relevant targets to manipulate the ependymal stem cell niche to achieve better healing after spinal cord injury.

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The honey bee stinger: An unusual pump with collapsible double pistons.

Most stinging animals deliver venom by contracting muscles around a venom reservoir, but honey bees employ a fundamentally different strategy. The stingers of worker bees have the unique ability to autotomize, separating from the body, to continue to sting independently. Despite more than a century of anatomical descriptions, the mechanics of venom pumping have remained unresolved due to the challenges of observing them in action. We recorded high-speed videos of active, autotomized stingers, co

Health & MedicineOctober 27, 2026

mechanoLight: A genetically encoded fluorescent biosensor for visualizing 5-HT2AR mechanotransduction in live cells.

G protein-coupled receptors (GPCRs) are pivotal sensors of the mechanical environment, yet how they sense and transduce physical stimuli into biochemical signals within live cells remains largely elusive. Here we introduce mechanoLight, a genetically encoded red fluorescent biosensor designed to report the mechanical activation of the 5-hydroxytryptamine 2A receptor (5-HT2AR). By incorporating a circularly permuted mApple (cp-mApple) into the third intracellular loop of 5-HT2AR with the optimize

Health & MedicineOctober 27, 2026

Neuromodulatory control of cortical function: Cell-type-specific regulation of neuronal information transfer.

Neuromodulatory systems such as dopamine and acetylcholine enable cortical circuits to rapidly shift between behavioral states, yet it remains unclear how receptor-specific signaling reshapes what single neurons compute. Here, we combined whole-cell recordings from excitatory and inhibitory neurons in layer 2/3 of mouse somatosensory cortex with information-theoretic analyses under frozen-noise stimulation. We quantified stimulus-to-spike information transfer and profiled each neuron across four

Health & MedicineOctober 27, 2026

Identification and characterization of neoplastic cells in keratin-positive giant cell-rich tumors.

Keratin-positive giant cell-rich tumor (KPGCT) is a newly described bone and soft tissue tumor. The tumor is characterized by scattered keratin-positive cells and the presence of HMGA2::NCOR2 fusions. It is not known if the HMGA2::NCOR2 fusion is located in the keratin-positive cells, and little is known about how KPGCT develops. KPGCT shares some histologic features with tenosynovial giant cell tumor (TGCT), a soft tissue tumor with CSF1 rearrangements. Single-nuclei RNA sequencing and Xenium s

Health & MedicineOctober 27, 2026

Mediator-associated proteins and the small RNA-guided Polycomb repressive complex enhance cryptic transcription for transposon exclusion.

Suppression of transposable elements (TEs) is critical for maintaining genome integrity. The evolutionary arms race between TEs and their eukaryotic host organisms has driven the development of small RNA-dependent mechanisms that specifically suppress TEs while leaving non-TE regions unperturbed. In the binucleated ciliate Tetrahymena , small RNAs (sRNAs) are generated from both TE and non-TE regions of the germline genome, whereas noncoding RNAs (ncRNAs) from the TE-free somatic genome target a