Origins of choice-related activity in mouse somatosensory cortex

• Published in: Nature neuroscience Vol. 19; no. 1; pp. 127 - 134
• Main Authors: Yang, Hongdian, Kwon, Sung E, Severson, Kyle S, O'Connor, Daniel H
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.01.2016; Nature Publishing Group
• Subjects: 14; 14/69; 631/378/2620/2618; 631/378/2620/2622; 631/378/2620/2623; 631/378/3917; 631/378/3920; 64/110; 64/60; Animal Genetics and Genomics; Animals; Behavior, Animal - physiology; Behavioral Sciences; Biological Techniques; Biomedicine; Brain research; Choice Behavior - physiology; Decision-making; Electrophysiological Phenomena; Female; Male; Mechanoreceptors - physiology; Mice; Mice, Inbred C57BL; Neural circuitry; Neurobiology; Neurons; Neurons - physiology; Neurosciences; Observations; Optogenetics; Patch-Clamp Techniques; Perception; Psychological aspects; Psychomotor Performance - physiology; Signal Detection, Psychological - physiology; Somatosensory Cortex - physiology; Somatosensory system; Touch Perception - physiology; Ventral Thalamic Nuclei - physiology; Vibrissae
• ISSN: 1097-6256; 1546-1726
• DOI: 10.1038/nn.4183

Sensory cortex spiking is well known to predict trial-to-trial variability in perceptual choice, but the origins of this choice-related activity are not fully understood. In the mouse somatosensory system, electrophysiology, imaging and optogenetic experiments reveal a progression of choice-related activity as touch signals flow from primary afferents to cortex. During perceptual decisions about faint or ambiguous sensory stimuli, even identical stimuli can produce different choices. Spike trains from sensory cortex neurons can predict trial-to-trial variability in choice. Choice-related spiking is widely studied as a way to link cortical activity to perception, but its origins remain unclear. Using imaging and electrophysiology, we found that mouse primary somatosensory cortex neurons showed robust choice-related activity during a tactile detection task. Spike trains from primary mechanoreceptive neurons did not predict choices about identical stimuli. Spike trains from thalamic relay neurons showed highly transient, weak choice-related activity. Intracellular recordings in cortex revealed a prolonged choice-related depolarization in most neurons that was not accounted for by feed-forward thalamic input. Top-down axons projecting from secondary to primary somatosensory cortex signaled choice. An intracellular measure of stimulus sensitivity determined which neurons converted choice-related depolarization into spiking. Our results reveal how choice-related spiking emerges across neural circuits and within single neurons.