Periodic Spiking Response to High-Frequency Stimulation in Cortical Cultures

The brain is accomplished at tracking various intervals of time, whether over a day or less than a second. It has been demonstrated that cortical networks possess an intrinsic ability to track subsecond intervals of time through intracellular recordings (Goel and Buonomano, 2016). However, it is still little understood how the network encodes this precise timing information through spiking. The goal of this study is to examine whether periodic stimulation of a cortical network results in a temporal spiking response within the network. To accomplish this, organotypic cultures were recorded from and stimulated on a 512-Microelectrode Array (MEA). A circle of electrodes was stimulated at 100 Hz and the temporal response of the spiking neurons was assessed. Stimulation was found to evoke periodic bursting within the network. In dissociated cultures, bursting is often thought to interfere with a network's ability to learn. In organotypic cultures, however, which have a lower intrinsic burst rate, this periodic bursting may be evidence of the network encoding a temporal interval through spiking.