Can a Synaptic Signal Arise from Noise?

Can a Synaptic Signal Arise from Noise?

The spontaneous fusion of vesicles at nerve terminals produces random miniature postsynaptic potentials (quantal responses) that are thought to have little functional significance. In this issue of Neuron, Sharma and Vijayaraghavan provide evidence that exogenous signals can accelerate and synchronize the occurrence of quanta strongly enough to activate postsynaptic neurons in what may be a new...

Mirror Symmetric Topographic Maps Can Arise from Activity-Dependent Synaptic Changes

Multiple adjacent, roughly mirror-image topographic maps are commonly observed in the sensory neocortex of many species. The cortical regions occupied by these maps are generally believed to be determined initially by genetically controlled chemical markers during development, with thalamocortical afferent activity subsequently exerting a progressively increasing influence over time. Here we us...

How life can arise from chemistry

Separating signal from noise

Suppose that a sequence of numbers xn (a ‘signal’) is transmitted through a noisy channel. The receiver observes a noisy version of the signal with additive random fluctuations, xn + ξn, where ξn is a sequence of independent standard Gaussian random variables. Suppose further that the signal is known to come from some fixed space X of possible signals. Is it possible to fully recover the transm...

Intrahepatic cholangiocarcinoma can arise from Notch-mediated conversion of hepatocytes.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary malignancy in the liver. ICC has been classified as a malignant tumor arising from cholangiocytes; however, the co-occurrence of ICC and viral hepatitis suggests that ICC originates in hepatocytes. In order to determine the cellular origin of ICC, we used a mouse model of ICC in which hepatocytes and cholangiocytes were lab...