Astrocytes release prostaglandin E2 to modify respiratory network activity.

Previously (Forsberg et al., 2016), we revealed that prostaglandin E2 (PGE2), released during hypercapnic challenge, increases calcium oscillations in the chemosensitive parafacial respiratory group (pFRG/RTN). Here, we demonstrate that pFRG/RTN astrocytes are the PGE2 source.

Planar cell polarity gene expression correlates with tumor cell viability and prognostic outcome in neuroblastoma.

Background: The non-canonical Wnt/Planar cell polarity (PCP) signaling pathway is a major player in cell migration during embryonal development and has recently been implicated in tumorigenesis.

Methods: Transfections with cDNA plasmids or siRNA were used to increase and suppress Prickle1 and Vangl2 expression in neuroblastoma cells and in non-tumorigenic cells. Cell viability was measured by trypan blue exclusion and protein expression was determined with western blotting.

Adult neural precursor cells form connexin-dependent networks that improve their survival.

Establishment of cellular networks and calcium homeostasis are essential for embryonic stem cell proliferation and differentiation. We also hypothesized that adult neural progenitor cells form functional cellular networks relevant for their development. We isolated neuronal progenitor cells from the subventricular zone of 5-week-old mice to investigate the role of gap junctions, calcium homeostasis, and cellular networks in cell differentiation and survival.

Transgenic increase of Wnt7b in neural progenitor cells decreases expression of T-domain transcription factors and impairs neuronal differentiation.

Wnt/beta-catenin signaling plays an important role in neural development, instructing both progenitor cell division and differentiation. During early corticogenesis, Wnt7b is expressed in a restricted expression pattern in the ventricular zone progenitor cells. However, its influence on progenitor cell behavior has not been fully studied.

Premature expression of KCC2 in embryonic mice perturbs neural development by an ion transport-independent mechanism.

During neuronal maturation, the neuron-specific K-Cl co-transporter KCC2 lowers the intracellular chloride and thereby renders GABAergic transmission hyperpolarizing. Independently of its role as a co-transporter, KCC2 plays a crucial role in the maturation of dendritic spines, most probably via an interaction with the cytoskeleton-associated protein 4.1N.

Vang-like protein 2 and Rac1 interact to regulate adherens junctions.

The Wnt planar cell polarity (Wnt/PCP) pathway signals through small Rho-like GTPases to regulate the cytoskeleton. The core PCP proteins have been mapped to the Wnt/PCP pathway genetically, but the molecular mechanism of their action remains unknown. Here, we investigate the function of the mammalian PCP protein Vang-like protein 2 (Vangl2).

Slits are chemorepellents endogenous to hypothalamus and steer thalamocortical axons into ventral telencephalon.

Thalamocortical axons (TCAs) originate in dorsal thalamus, extend ventrally along the lateral thalamic surface, and as they approach hypothalamus make a lateral turn into ventral telencephalon. In vitro studies show that hypothalamus releases a chemorepellent for TCAs, and analyses of knockout mice indicate that Slit chemorepellents and their receptor Robo2 influence TCA pathfinding. We show that Slit chemorepellents are the hypothalamic chemorepellent and act through Robos to steer TCAs into ventral telencephalon.

Prenatal exposure to nicotine affects substance p and preprotachykinin-A mRNA levels in newborn rat.

Prenatal nicotine exposure influences neuronal development including effects on several neurotransmitter systems. It also attenuates the ventilatory response to hypoxia, known to require a functional substance P-ergic system. Previous studies have shown that nicotine increases the risk for sudden infant death syndrome (SIDS) by 4-fold, and that SIDS-victims have elevated brainstem levels of substance P.

Wnt7a overexpression delays beta-tubulin III expression in transgenic mouse embryos.

Wnt7a and HA-tagged Wnt7a have previously been shown to promote or delay neuronal differentiation respectively. In this study, we show that embryonic days 9.5 and 10.

Increased Wnt levels in the neural tube impair the function of adherens junctions during neurulation.

Wnt7a has been reported to signal via the canonical pathway, but also in non-canonical pathways acting on the cytoskeleton. Since Wnt7a is expressed after neurulation, we set to investigate the effects of Wnt7a on brain regionalization. We engineered transgenic mouse embryos that, under control of the nestin second intron, overexpressed Wnt7a in neural stem/progenitor cells.

EMX2 regulates sizes and positioning of the primary sensory and motor areas in neocortex by direct specification of cortical progenitors.

Genetic studies of neocortical area patterning are limited, because mice deficient for candidate regulatory genes die before areas emerge and have other complicating issues. To define roles for the homeodomain transcription factor EMX2, we engineered nestin-Emx2 transgenic mice that overexpress Emx2 in cortical progenitors coincident with expression of endogenous Emx2 and survive postnatally. Cortical size, lamination, thalamus, and thalamocortical pathfinding are normal in homozygous nestin-Emx2 mice.