Abstract
Animals are constantly exposed to the time-varying visual world. Because visual perception is modulated by immediately prior visual experience, visual cortical neurons may register recent visual history into a specific form of offline activity and link it to later visual input. To examine how preceding visual inputs interact with upcoming information at the single neuron level, we designed a simple stimulation protocol in which a brief, orientated flashing stimulus was subsequently coupled to visual stimuli with identical or different features. Using in vivo whole-cell patch-clamp recording and functional two-photon calcium imaging from the primary visual cortex (V1) of awake mice, we discovered that a flash of sinusoidal grating per se induces an early, transient activation as well as a long-delayed reactivation in V1 neurons. This late response, which started hundreds of milliseconds after the flash and persisted for approximately 2 s, was also observed in human V1 electroencephalogram. When another drifting grating stimulus arrived during the late response, the V1 neurons exhibited a sublinear, but apparently increased response, especially to the same grating orientation. In behavioral tests of mice and humans, the flashing stimulation enhanced the detection power of the identically orientated visual stimulation only when the second stimulation was presented during the time window of the late response. Therefore, V1 late responses likely provide a neural basis for admixing temporally separated stimuli and extracting identical features in time-varying visual environments.
Highlights
The primary visual cortex (V1) has been used as an experimental model to study cortical responses to sensory input
Using in vivo whole-cell patch-clamp recording and functional two-photon calcium imaging from the primary visual cortex (V1) of awake mice, we discovered that a flash of sinusoidal grating per se induces an early, transient activation as well as a long-delayed reactivation in V1 neurons
Animals are constantly exposed to a visual world that varies over time
Summary
The primary visual cortex (V1) has been used as an experimental model to study cortical responses to sensory input. V1 receives direct synaptic inputs from the lateral geniculate nucleus (LGN) of the thalamus and provides the output of its computation to higher-order cortical areas [1,2]. This route, commonly known as the feed forward pathway, contributes to the hierarchical neural processing of specific visual features, such as orientation, direction, color, and motion. Recent evidence has demonstrated that V1 activity persists over time [3,4,5,6,7] and even propagates throughout the V1 network [8,9]. Reverberatory neuronal activity within neocortical circuitry has been proposed as a potential mechanism for short-term storage of information [15,16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
