Rhythmic air-puff into nasal cavity modulates activity across multiple brain areas: A non-invasive brain stimulation method to reduce ventilator-induced memory impairment.

Mechanical ventilation (MV) can result in long-term brain impairments that are resistant to treatment. The mechanisms underlying MV-induced brain function impairment remain unclear. Since nasal airflow modulates brain activity, here we evaluated whether reinstating airflow during MV could influence the memory performance of rats after recovery.

State-Dependent Changes in Perception and Coding in the Mouse Somatosensory Cortex.

An animal's behavioral state is reflected in the dynamics of cortical population activity and its capacity to process sensory information. To better understand the relationship between behavioral states and information processing, mice are trained to detect varying amplitudes of whisker-deflection under two-photon calcium imaging. Layer 2/3 neurons in the vibrissal primary somatosensory cortex are imaged across different behavioral states, defined based on detection performance (low to high-state) and pupil diameter.

Superior colliculus modulates cortical coding of somatosensory information.

The cortex modulates activity in superior colliculus via a direct projection. What is largely unknown is whether (and if so how) the superior colliculus modulates activity in the cortex. Here, we investigate this issue and show that optogenetic activation of superior colliculus changes the input-output relationship of neurons in somatosensory cortex, enhancing responses to low amplitude whisker deflections.

Differences in perceptual masking between humans and rats.

Introduction: The perception of a target stimulus can be impaired by a subsequent mask stimulus, even if they do not overlap temporally or spatially. This "backward masking" is commonly used to modulate a subject's awareness of a target and to characterize the temporal dynamics of vision. Masking is most apparent with brief, low-contrast targets, making detection difficult even in the absence of a mask.

Diverse tuning underlies sparse activity in layer 2/3 vibrissal cortex of awake mice.

Key Points: Sparse population activity is a common feature observed across cortical areas, yet the implications for sensory coding are not clear. We recorded single neuron activity in the vibrissal somatosensory cortex of awake head-fixed mice using the cell-attached technique. Unlike the anaesthetised condition, in awake mice a high-velocity, piezo-controlled whisker deflection excited only a small fraction of neurons.

Temporal cueing enhances neuronal and behavioral discrimination performance in rat whisker system.

Since sensory systems operate with a finite quantity of processing resources, an animal would benefit from prioritizing processing of sensory stimuli within a time window that is expected to provide key information. This behavioral manifestation of such prioritization is known as attention. Here, we investigate attention with temporal cueing and its neuronal correlates in the rat primary vibrissal somatosensory (vS1) cortex.

Human-like perceptual masking is difficult to observe in rats performing an orientation discrimination task.

Visual masking occurs when the perception of a brief target stimulus is affected by a preceding or succeeding mask. The uncoupling of the target and its perception allows an opportunity to investigate the neuronal mechanisms involved in sensory representation and visual perception. To determine whether rats are a suitable model for subsequent studies of the neuronal basis of visual masking, we first demonstrated that decoding of neuronal responses recorded in the primary visual cortex (V1) of anaesthetized rats predicted that orientation discrimination performance should decline when masking stimuli are presented immediately before or after oriented target stimuli.

Integration of visual and whisker signals in rat superior colliculus.

Multisensory integration is a process by which signals from different sensory modalities are combined to facilitate detection and localization of external events. One substrate for multisensory integration is the midbrain superior colliculus (SC) which plays an important role in orienting behavior. In rodent SC, visual and somatosensory (whisker) representations are in approximate registration, but whether and how these signals interact is unclear.

Information processing across behavioral states: Modes of operation and population dynamics in rodent sensory cortex.

Animals live in a complex and changing environment with various degrees of behavioral demands. In rodents, the behavioral states can change from sleep and quiet wakefulness to active exploration of the environment which is often manifested by whisking and locomotion. Efficient information processing is more important in some of these behavioral states such as during episodes of sensory decision-making, and specific cortical areas are expected to receive priority of processing depending on the behavioral context.

High-velocity stimulation evokes "dense" population response in layer 2/3 vibrissal cortex.

Supragranular layers of sensory cortex are known to exhibit sparse firing. In rodent vibrissal cortex, a small fraction of neurons in layer 2 and 3 (L2/3) respond to whisker stimulation. In this study, we combined whole cell recording and two-photon imaging in anesthetized mice and quantified the synaptic response and spiking profile of L2/3 neurons.

Sensory Prioritization in Rats: Behavioral Performance and Neuronal Correlates.

Unlabelled: Operating with some finite quantity of processing resources, an animal would benefit from prioritizing the sensory modality expected to provide key information in a particular context. The present study investigated whether rats dedicate attentional resources to the sensory modality in which a near-threshold event is more likely to occur. We manipulated attention by controlling the likelihood with which a stimulus was presented from one of two modalities.