Diffuse gliomas, particularly glioblastomas, are incurable brain tumours. They are characterized by networks of interconnected brain tumour cells that communicate via Ca2+ transients. However, the networks’ architecture and communication strategy and how these influence tumour biology remain unknown. Here we describe how glioblastoma cell networks include a small, plastic population of highly active glioblastoma cells that display rhythmic Ca2+ oscillations and are particularly connected to others. Their autonomous periodic Ca2+ transients preceded Ca2+ transients of other network-connected cells, activating the frequency-dependent MAPK and NF-κB pathways.

The sense of smell supports the identification and the safety of food, warns of danger/predators, and plays a key role in mating (Croy and Hummel, 2017; Kondo et al., 2020; Tzeng et al., 2021). Via connection to the limbic system, it supports behavioral adaption and emotions and can detect fear, tears, and happiness in the body odor of others (Croy and Hummel, 2017; Tzeng et al., 2021).

Trypanosoma brucei is the causative agent of human African trypanosomiasis. The parasite transmigrates from blood vessels across the choroid plexus epithelium to enter the central nervous system, a process that leads to the manifestation of second stage sleeping sickness. Using an in vitro model of the blood-cerebrospinal fluid barrier, we investigated the mechanism of the transmigration process.

The cuprizone model is a widely used model to study the pathogenesis of multiple sclerosis (MS). Due to the selective loss of mature oligodendrocytes and myelin, it is mainly being used to study demyelination and the mechanisms of remyelination, as well as the efficiency of compounds or therapeutics aiming at remyelination. Although early investigations using high dosages of cuprizone reported the occurrence of hydrocephalus, it has long been assumed that cuprizone feeding at lower dosages does not induce changes at the blood–brain barrier (BBB).

Under physiological conditions microglia, the immune sentinels of the brain, constantly monitor their microenvironment. In the case of danger, damage or cell/tissue dyshomeostasis, they react with changes in process motility, polarization, directed process movement, morphology and gene expression profile; release pro- and anti-inflammatory mediators; proliferate; and clean brain parenchyma by means of phagocytosis.

Intrinsic neuronal activity is a hallmark of the developing brain. In rodents, a handful of such activities were described in different cortical areas but the unifying macroscopic perspective is still lacking.

Peripheral inflammation is known to impact brain function, resulting in lethargy, loss of appetite and impaired cognitive abilities. However, the channels for information transfer from the periphery to the brain, the corresponding signaling molecules and the inflammation-induced interaction between microglia and neurons remain obscure.

The rodent olfactory bulb (OB) is continuously supplied with adult-born cells maturing into GABAergic neurons. Using in vivo ratiometric Ca2+ imaging to readout ongoing and sensory-driven activity, we asked whether mature adult-born cells (mABCs) in the glomerular layer of the bulb become functionally identical to resident GABAergic (Res_GABA) neurons.

Background

Throughout the lifespan, microglia, the primary innate immune cells of the brain, fulfill a plethora of homeostatic as well as active immune defense functions, and their aging-induced dysfunctionality is now considered as a key trigger of aging-related brain disorders. Recent evidence suggests that both organism’s sex and age critically impact the functional state of microglia but in vivo determinants of such state(s) remain unclear.

Therefore, we analyzed in vivo the sex-specific functional states of microglia in young adult, middle aged and old wild type mice by means of multicolor two-photon imaging, using the microglial Ca2 + signaling and directed process motility as main readouts. 

read more: https://www.frontiersin.org/articles/10.3389/fimmu.2020.00750/full