#primary visual cortex

Vision Loss

Traumatic brain injuries (TBI) are unfortunately quite common in humans. Mild cases may only affect your brain temporarily, but other more serious cases can cause long-term complications. TBI can often lead to long-lasting visual impairments like an inability to define shapes, a misalignment of the images that our brain processes from our eyes or a loss of spatial awareness. But why TBI causes these symptoms wasn’t clear until now. Researchers studied mice who had suffered a brain injury (damaged area shown in pink in these brain slices) and discovered that while the primary visual cortex, the region of the brain that processes visual cues, remained intact; there was a significant loss of neurons that were able to relay that information from the eye to the brain. Moreover, this ‘single blow’ appeared to cause permanent damage, but this knowledge is helpful to develop future therapy options including neuron transplantation.

Written by Sophie Arthur

Image from work by Jan C. Frankowski and Andrzej T. Foik, and colleagues

Department of Anatomy & Neurobiology, University of California, Irvine, CA, USA

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Communications Biology, November 2021

Surprise Discovery Reveals Second Visual System in Cerebral Cortex: Mouse Study

"This undermines the whole concept of the visual system in mammalian cortex as a perfect hierarchy with V1 as the gatekeeper and raises a multitude of questions, including how these two parallel visual systems evolved and how they cooperate to produce a unified visual experience."

The Discoveries in Neuroscience about Spatial perception of the visually impaired

There are some findings of the function of the primary visual cortex of blind people.

From the discoveries in neuroscience informed us of the following facts.

The blind people’s visual cortex wasn’t lying dormant, it had been recruited by other senses (Kennedy and Juricevic, 2006).

Another fact is that Visio-auditory interactions occur in the primary visual cortex of blind people.…

The Blind Woman Who Saw Rain

A few moments from Skunk Bear's new video about Milena Channing -- a woman blinded by a stroke -- who begins to see moving objects:

New Respect for Primary Visual Cortex

A previously underappreciated brain region performs complex sequence learning.

In the context of learning and memory, the primary visual cortex is the Rodney Dangerfield of cortical areas: It gets no respect. Also known as “V1,” this brain region is the very first place where information from the retina arrives in the cerebral cortex.

New theory explains how critical periods are triggered during development of the nervous system

Experiments performed in the 1960s showed that rearing young animals with one eye closed dramatically altered brain development such that the parts of the visual cortex that would normally process information from the closed eye instead process information from the open eye. These effects can be induced only within a specific period of time—a 'critical' period during which the developing nervous system is particularly sensitive to its environment.

Subsequent work has shown that the onset of the critical period in the primary visual cortex requires the maturation of circuits containing neurons that synthesize and release an inhibitory neurotransmitter called gamma-aminobutyric acid (GABA). Now, Taro Toyoizumi and colleagues from the RIKEN Brain Science Institute have presented a theory that explains how this inhibition triggers the critical period.