Genesis of a functional astrocyte syncytium in the developing mouse hippocampus.

Astrocytes are increasingly shown to operate as an isopotential syncytium in brain function. Protoplasmic astrocytes acquire this ability to functionally go beyond the single-cell level by evolving into a spongiform morphology, cytoplasmically connecting into a syncytium, and expressing a high density of K conductance. However, none of these cellular/functional features exist in neonatal newborn astrocytes, which imposes a basic question of when a functional syncytium evolves in the developing brain.

Clinicopathologic features of scrotal leiomyosarcoma: single institutional experience of ten cases.

Scrotal leiomyosarcoma arises from the subcutaneous smooth muscle layer and is an exceptionally rare disease process, with only six patients in the largest reported case series. This rarity creates uncertainties regarding diagnosis, surgical management, and clinical outcomes. Our purpose was to retrospectively describe our institutional experience with scrotal leiomyosarcoma from 2010 to 2022.

Ultrastructural view of astrocyte arborization, astrocyte-astrocyte and astrocyte-synapse contacts, intracellular vesicle-like structures, and mitochondrial network.

The complexity of astrocyte morphology and syncytial coupling through gap junctions are crucial for astrocyte function in the brain. However, the ultrastructural details of astrocyte arborization and interactions between neighboring astrocytes remain unknown. While a prevailing view is that synapses selectively contact peripheral astrocyte processes, the precise spatial-location selectivity of synapses abutting astrocytes is unresolved.

TREK-1 Null Impairs Neuronal Excitability, Synaptic Plasticity, and Cognitive Function.

TREK-1, a two-pore-domain K channel, is highly expressed in the central nervous system. Although aberrant expression of TREK-1 is implicated in cognitive impairment, the cellular and functional mechanism underlying this channelopathy is poorly understood. Here we examined TREK-1 contribution to neuronal morphology, excitability, synaptic plasticity, and cognitive function in mice deficient in TREK-1 expression.

Syncytial isopotentiality: A system-wide electrical feature of astrocytic networks in the brain.

Syncytial isopotentiality, resulting from a strong electrical coupling, emerges as a physiological mechanism that coordinates individual astrocytes to function as a highly efficient system in brain homeostasis. However, whether syncytial isopotentiality occurs selectively to certain brain regions or is universal to astrocytic networks remains unknown. Here, we have explored the correlation of syncytial isopotentiality with different astrocyte subtypes in various brain regions.

Dissipation of transmembrane potassium gradient is the main cause of cerebral ischemia-induced depolarization in astrocytes and neurons.

Membrane potential (V) depolarization occurs immediately following cerebral ischemia and is devastating for the astrocyte homeostasis and neuronal signaling. Previously, an excessive release of extracellular K and glutamate has been shown to underlie an ischemia-induced V depolarization. Ischemic insults should impair membrane ion channels and disrupt the physiological ion gradients.