The role of feedback projections in feature tuning and neuronal excitability in the early primate visual system

The role of feedback projections in feature tuning and neuronal excitability in the early primate visual system

A general assumption in visual neuroscience is that basic receptive field properties such as orientation and direction selectivity are constructed within intrinsic neuronal circuits and feedforward projections. In addition, it is assumed that general neuronal excitability and responsiveness in early...

Full description

Saved in:
Bibliographic Details
Published in:Brain Structure and Function Vol. 226; no. 9; pp. 2881 - 2895
Main Authors: Correia, A. R. A., Amorim, A. K. J., Soares, J. G. M., Lima, B., Fiorani, M., Gattass, R.
Format: Journal Article
Language:English
Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2021
Springer Nature B.V
Subjects:
Animals
Biomedical and Life Sciences
Biomedicine
Cell Biology
Excitability
Feedback
gamma-Aminobutyric Acid
Information processing
Injection
Nervous system
Neural coding
Neurology
Neurons
Neurosciences
Orientation behavior
Photic Stimulation
Primates
Pulvinar
Receptive field
Review
Unit activity
Visual field
Visual Pathways
Visual system
γ-Aminobutyric acid
Feature tuning
GABA inactivation
Area V2
Feedback projections
Primate visual system
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A general assumption in visual neuroscience is that basic receptive field properties such as orientation and direction selectivity are constructed within intrinsic neuronal circuits and feedforward projections. In addition, it is assumed that general neuronal excitability and responsiveness in early visual areas is to a great extent independent of feedback input originating in areas higher in the stream. Here, we review the contribution of feedback projections from MT, V4 and pulvinar to the receptive field properties of V2 neurons in the anesthetized and paralyzed monkey. Importantly, our results contradict both of these assumptions. We separately inactivated each of these three brain regions using GABA pressure injections, while simultaneously recording V2 single unit activity before and hours after inactivation. Recordings and GABA injections were carried out in topographically corresponding regions of the visual field. We outline the changes in V2 activity, responsiveness and receptive field properties for early, mid and late post-injection phases. Immediately after injection, V2 activity is globally suppressed. Subsequently, there is an increase in stimulus-driven relative to spontaneous neuronal activity, which improves the signal-to-noise coding for the oriented moving bars. Notably, V2 tuning properties change substantially relative to its pre-injection selectivity profile. The resulting increase or decrease in selectivity could not be readily predicted based on the selectivity profile of the inactivated site. Finally, V2 activity rebounds before returning to it pre-injection profile Our results show that feedback projections profoundly impact neuronal circuits in early visual areas, and may have been heretofore largely underestimated in their physiological role. Graphic abstract
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-3
content type line 23
ObjectType-Review-1
ISSN:1863-2653
1863-2661
0340-2061
DOI:10.1007/s00429-021-02311-x