I’ll be continually updating this page as I get more recordings.

Often neurophysiologists who work with freely behaving rats have to attend to the rat and can not always keep their eyes on their oscilloscopes. Instead, many neurophysiologists rely on sound to listen for brain activity. Neural signals are often amplified then sent to speakers for the experimenter to listen to. These sounds can be very informative for what is going on in the brain. Are my electrodes getting close to a layer of cells? How many cells are on a given electrode? What are these cells responding to? Are these cells rhythmically modulated? Answers to all these questions and more can be gleaned from listening to the brain. Below you can find examples of different brain sounds. Mainly they are of cellular activity of neurons. Each “pop” is a neuron firing an action potential; the electrical signal that allows neuron to communicate with each other and the rest of the body. There are also recordings of brain oscillations; that is the gross electrical activity which results from the processing done by thousands of neurons.

Anterior Cingulate Interneuron

Anterior Cingulate Ensemble Activity

Sleeping Rat

Here is a neuron from the Dorsal aspect of the CA1 (dCA1) region of the Hippocampus which only fired when the rat was actively moving around an environment, searching out for food

Various neurons in the Anterior Cingulate Cortex as a rat searches for food

Below you can hear an orchestra of dCA1 cells processing a days worth of information as a rat takes a nap

A few fast firing interneurons can be heard from dCA1 of the Hippocampus

A single bursty interneuron from dCA1 of the Hippocampus in a free foraging rat

A small ensemble of neurons processing information as a rat runs on a track

Here are the deep sounds of the Theta rhythm. This rhythmic oscillation occurs in mammals as they actively explore an environment. Rather than individual cells, these sounds are the net result of thousands of cells acting together