This 2015 study found that a single brain neuron’s

“Spiking history is often a more informative predictor of spiking propensity than the signal or stimulus activating the neuron.

Characterizing the reliability with which neurons represent and transmit information is an important question in computational neuroscience.”

Three of the four brain neuron areas studied were of the limbic system: a rat thalamus, a monkey hippocampus, and a human subthalamus area.

http://www.pnas.org/content/112/23/7141.full.pdf “Measuring the signal-to-noise ratio of a neuron” (pdf file is linked because the html has errors)