Detecting RNA base methylations in single cells by in situ hybridization.

Methylated bases in tRNA, rRNA and mRNA control a variety of cellular processes, including protein synthesis, antimicrobial resistance and gene expression. Currently, bulk methods that report the average methylation state of ~10-10 cells are used to detect these modifications, obscuring potentially important biological information. Here, we use in situ hybridization of Molecular Beacons for single-cell detection of three methylations (mA, mG and mU) that destabilize Watson-Crick base pairs.

Individual aggregates of amyloid beta induce temporary calcium influx through the cell membrane of neuronal cells.

Local delivery of amyloid beta oligomers from the tip of a nanopipette, controlled over the cell surface, has been used to deliver physiological picomolar oligomer concentrations to primary astrocytes or neurons. Calcium influx was observed when as few as 2000 oligomers were delivered to the cell surface. When the dosing of oligomers was stopped the intracellular calcium returned to basal levels or below.

A mechanistic model of tau amyloid aggregation based on direct observation of oligomers.

Protein aggregation plays a key role in neurodegenerative disease, giving rise to small oligomers that may become cytotoxic to cells. The fundamental microscopic reactions taking place during aggregation, and their rate constants, have been difficult to determine due to lack of suitable methods to identify and follow the low concentration of oligomers over time. Here we use single-molecule fluorescence to study the aggregation of the repeat domain of tau (K18), and two mutant forms linked with familial frontotemporal dementia, the deletion mutant ΔK280 and the point mutant P301L.

Inhibition of Ih reduces epileptiform activity in rodent hippocampal slices.

Hyperpolarization-activated cyclic nucleotide gated (HCN) ion channels regulate membrane potential, neurotransmitter release, and patterning of synchronized neuronal activity. Currently, there is an intense debate as to whether or not these ion channels play a pro- or anticonvulsant role in vivo. To gain an insight into this question, we have examined how inhibitors of the response mediated by HCN channels (referred to as I(h)) affect epileptiform activity induced in adult hippocampal slices.