Fast Neuronal Calcium Signals in Brain Slices Loaded With Fluo-4 AM Ester.

Staining brain slices with acetoxymethyl ester (AM) Ca dyes is a straightforward procedure to load multiple cells, and Fluo-4 is a commonly used high-affinity indicator due to its very large dynamic range. It has been shown that this dye preferentially stains glial cells, providing slow and large Ca transients, but it is questionable whether and at which temporal resolution it can also report Ca transients from neuronal cells. Here, by electrically stimulating mouse hippocampal slices, we resolved fast neuronal signals corresponding to 1%-3% maximal fluorescence changes.

Neuronal Imaging at 8-Bit Depth to Combine High Spatial and High Temporal Resolution With Acquisition Rates Up To 40 kHz.

A challenge in neuroimaging is acquiring frame sequences at high temporal resolution from the largest possible number of pixels. Measuring 1%-10% fluorescence changes normally requires 12-bit or higher bit depth, constraining the frame size allowing imaging in the kHz range. We resolved Ca or membrane potential signals from cell populations or single neurons in brain slices by acquiring fluorescence at 8-bit depth and by binning pixels offline, achieving unprecedented frame sizes at kHz rates.

Nitric oxide modelling and its bioavailability influenced by red blood cells.

Nitric oxide (NO) is an important vasodilator responsible for maintaining vascular tone in the human body. Its production in endothelial cells (ECs) is regulated by the rise of cytoplasmic Ca concentration and shear stress perceived by blood flow. The increase in cytoplasmic Ca concentration is mainly activated by adenosine triphosphate (ATP) released from red blood cells (RBCs) and ECs.

Physiological Features of the Neural Stem Cells Obtained from an Animal Model of Spinal Muscular Atrophy and Their Response to Antioxidant Curcumin.

The most prevalent rare genetic disease affecting young individuals is spinal muscular atrophy (SMA), which is caused by a loss-of-function mutation in the telomeric gene survival motor neuron () . The high heterogeneity of the SMA pathophysiology is determined by the number of copies of , a separate centromeric gene that can transcribe for the same protein, although it is expressed at a slower rate. SMA affects motor neurons.

Analysis of the effect of the scorpion toxin AaH-II on action potential generation in the axon initial segment.

The toxin AaH-II, from the scorpion Androctonus australis Hector venom, is a 64 amino acid peptide that targets voltage-gated Na channels (VGNCs) and slows their inactivation. While at macroscopic cellular level AaH-II prolongs the action potential (AP), a functional analysis of the effect of the toxin in the axon initial segment (AIS), where VGNCs are highly expressed, was never performed so far. Here, we report an original analysis of the effect of AaH-II on the AP generation in the AIS of neocortical layer-5 pyramidal neurons from mouse brain slices.