Related Experiment Video
Updated: Mar 24, 2026
10:05
A Large Lateral Craniotomy Procedure for Mesoscale Wide-field Optical Imaging of Brain Activity
Published on: May 7, 2017
13.0K
Top-Down-Mediated Facilitation in the Visual Cortex Is Gated by Subcortical Neuromodulation
Diego E Pafundo1, Mark A Nicholas1, Ruilin Zhang1
1Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
Summary
Behavioral state influences sensory cortex responses. This study shows basal forebrain activation enhances visual cortex (V1) responses locally, without affecting higher-order visual areas, revealing distinct subcortical modulation.
Area of Science:
- Neuroscience
- Sensory processing
- Cortical circuits
Background:
- Behavioral state significantly modulates neural responses in sensory cortices.
- The basal forebrain is known to enhance neuronal responses in the primary visual cortex (V1) during active states.
- Reciprocal connections between cortical areas raise questions about how sensory gain is regulated to prevent overexcitation.
Purpose of the Study:
- To investigate how increases in sensory response gain are constrained within hierarchically organized cortical regions.
- To determine if basal forebrain-mediated gain modulation in V1 affects higher-order visual areas.
Main Methods:
- In vivo two-photon guided cell-attached recordings were used in mice.
- Spatially restricted optogenetic photo-inhibition of higher-order visual cortex was employed.
- Differential response properties between LM and V1 were analyzed.
Main Results:
- Feedback projections from the lateral medial area (LM) to V1 facilitated visual responses in layer 2/3 excitatory neurons by approximately 20%.
- Basal forebrain activation reduced this LM-V1 facilitation by half.
- These effects were attributed to differential response properties between LM and V1.
Conclusions:
- Basal forebrain-mediated increases in response gain are localized to V1 and do not propagate to LM.
- Subcortical modulation of the visual cortex is region-specific.
- This study elucidates the localized nature of sensory gain modulation within the visual hierarchy.
Related Concept Videos
01:24Vision
61.4K
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
61.4K
01:14Motor and Sensory Areas of the Cortex
8.9K
The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex....
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex....
8.9K