Biology subjects

Sokoletsky, M.

Publications and source records attributed to Sokoletsky, M..

4 recordsLinked to original sources

bioRxiv2025

Inherent coupling of perceptual judgments to actions in the mouse cortex

Neural activity during perceptual tasks is distributed across many cortical regions, but it remains unclear where perceptual judgments are made and whether they are encoded independently of the resulting actions. To address these questions, we designed a vibrotactile detection task in which mice flexibly switched between standard and reversed contingency blocks, requiring them to lick when a stimulus was present or absent, depending on the block. A cortex-wide optogenetic screen revealed that the premotor cortex is important for perceptual judgments rather than the ability to lick. However, coding of perceptual judgments in the premotor cortex and other cortical regions was coupled to actions rather than being independent of them. Finally, we identified a subset of premotor cortex cells whose activity encoded the current block identity. Based on these findings, we propose a model in which vibrotactile perceptual judgments are inherently, but flexibly, coupled to actions via cortical activity.

neuroscience↗

bioRxiv2022

Isolated correlates of somatosensory perception in the mouse posterior cortex

To uncover the neural correlates of stimulus perception, experimenters commonly use tasks in which subjects are repeatedly presented with a weak stimulus and instructed to report, via movement, if they perceived the stimulus. The difference in neural activity between reported stimulus (hit) and unreported stimulus (miss) trials is then seen as potentially perception-related. However, recent studies found that activity related to the report spreads throughout the brain, calling into question to what extent such tasks conflate perception-related activity with report-related activity. To isolate perception-related activity, we developed a paradigm in which the same mice were trained on both a regular go/no-go whisker stimulus detection task and a reversed contingencies version, in which they reported the absence of a whisker stimulus. By comparing no-report trials across the two tasks, we located perception-related activity within a posterior network of cortical regions contralateral to the stimulus. In addition, we found this activity was on average an order of magnitude lower than report-related activity and began after the low-level stimulus response. In summary, our study revealed the mouse cortical areas associated with the perception of a sensory stimulus independently of a perceptual report.

neuroscience↗

bioRxiv2019

Multiple timescales account for adaptive responses across sensory cortices

Sensory systems encounter remarkably diverse stimuli in the external environment. Natural stimuli exhibit timescales and amplitudes of variation that span a wide range. Mechanisms of adaptation, ubiquitous feature of sensory systems, allow for the accommodation of this range of scales. Are there common rules of adaptation across different sensory modalities? We measured the membrane potential responses of individual neurons in the visual, somatosensory and auditory cortices to discrete, punctate stimuli delivered at a wide range of fixed and nonfixed frequencies. We find that the adaptive profile of the response is largely preserved across these three areas, exhibiting attenuation and responses to the cessation of stimulation which are signatures of response to changes in stimulus statistics. We demonstrate that these adaptive responses can emerge from a simple model based on the integration of fixed filters operating over multiple time scales.

neuroscience↗

bioRxiv2019

Stereotactic system for accurately targeting deep brain structures in awake head-fixed mice

Deep brain nuclei, such as the amygdala, nucleus basalis, and locus coeruleus, play a crucial role in cognition and behavior. Nonetheless, acutely recording electrical activity from these structures in head-fixed awake rodents has been very challenging due to the fact that head-fixed preparations are not designed for stereotactic accuracy. We overcome this issue by designing the DeepTarget, a system for stereotactic head-fixation and recording, which allows for accurately directing recording electrodes or other probes into any desired location in the brain. We then validated it by performing intracellular recordings from optogenetically-tagged amygdalar neurons followed by histological reconstruction, which revealed that it is accurate and precise to within [~]100 m. Moreover, in another group of mice we were able to target both the mammillothalamic tract and subthalamic nucleus. This approach can be adapted to any type of extracellular electrode, fiber optic or other probe in cases where high accuracy is needed in awake, head-fixed rodents. Highlights> The Deep Target, new system for accurately targeting deep nuclei in head-fixed animals for electrophysiology and optogenetics. > Accurate and precise to within 100 m following a one-time alignment. > Validation: Opto-tagged Vm recordings in the amygdala of awake mice. > Validation: Targeting multiple deep brain structures in the same mouse.

neuroscience↗