Abstract
In contrast to the long-standing notion that the role of individual neurons in population activity is vanishingly small, recent studies have shown that electrical activation of only a single cortical neuron can have measurable effects on global brain state, movement, and perception. Although highly important for understanding how neuronal activity in cortex is orchestrated, the cellular and network mechanisms underlying this phenomenon are unresolved. Here, we first briefly review the current state of knowledge regarding the phenomenon of single-cell induced network modulation and discuss possible underpinnings. Secondly, we show proof of principle for an experimental approach to elucidate the mechanisms of single-cell induced changes in cortical activity. The setup allows simultaneous recordings of the spiking activity of multiple neurons across all layers of the cortex using a multi-electrode array, while manipulating the activity of one individual neuron in close proximity to the array. We demonstrate that single cells can be recorded and stimulated reliably for hundreds of trials, conferring high statistical power even for expectedly small effects of single-neuron spiking on network activity. Preliminary results suggest that single-cell stimulation on average decreases the firing rate of local network units. We expect that characterization of the spatiotemporal spread of single-cell evoked activity across layers and columns will yield novel insights into intracortical processing.
Highlights
IntroductionIt remains essentially a mystery how neuronal networks process information [1]
Despite decades of research, it remains essentially a mystery how neuronal networks process information [1]
The basic setup consisted of a head-holder for the rat, one micromanipulator to position the glass pipette for juxtacellular recording and stimulation, another micromanipulator to position a multi-electrode array, and a whisker stimulator
Summary
It remains essentially a mystery how neuronal networks process information [1]. ] As single neurons are not very informative, to obtain accurate information about sensory or motor variables some sort of population averaging must be performed” [2]. Responses of individual neurons in sensory cortex in response to repeated presentations of physically identical stimuli displays high trial-by-trial variability [3], which can in principle severely hamper the decoding of information by downstream neurons. The vast majority of neurons in the whisker area of primary somatosensory cortex (“barrel cortex” [4]) provide relatively little information on both the identity of a stimulated whisker and the frequency at which it is stimulated [5]. Small ensembles of neurons in rat somatosensory cortex outperform individual neurons by a factor of seven in determining the identity of a single stimulated whisker [6]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have