Neuroscience

How the brain interprets motion while in motion

Imagine you're sitting on a train. You look out the window and see another train on an adjacent track that appears to be moving. But, has your train stopped while the other train is moving, or are you moving while the other ...

Ophthalmology

Cell fusion 'awakens' regenerative potential of human retina

Fusing human retinal cells with adult stem cells could be a potential therapeutic strategy to treat retinal damage and visual impairment, according to the findings of a new study published in the journal eBioMedicine. The ...

Ophthalmology

'Bunkers' that save eyesight? Researchers take a close look

Chronically stressing the retina can weaken it and damage our ability to see. But retinal cells have a remarkable ability to wall off damage, a team of neuroscientists led by UConn Health reports in the 1 March issue of PNAS. ...

Ophthalmology

Improved retinal transplant technique ready for clinical trials

Researchers led by Michiko Mandai at the RIKEN Center for Biosystems Dynamics Research (BDR) in Japan have used a genetic modification to improve human-derived retina transplants grown in the lab. After transplant into damaged ...

Neuroscience

Study reveals journey of immune cells in developing zebrafish

Microglia, the immune cells of the brain, form the first line of defense against neurodegenerative diseases and traumatic brain injuries. They maintain brain homeostasis, the stable condition necessary for survival, by acting ...

Health

'Exercise in a pill' could offer solution for at-risk people

Researchers from The Australian National University (ANU) have identified unique molecular signals in the body that could hold the key to developing a supplement capable of administering the health benefits of exercise to ...

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Retina

The vertebrate retina is a light sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centers of the brain through the fibers of the optic nerve.

In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system (CNS).. It is the only part of the CNS that can be imaged non-invasively in the living organism.

The retina is a complex, layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light and provide black-and-white vision, while cones support daytime vision and the perception of colour. A third, much rarer type of photoreceptor, the photosensitive ganglion cell, is important for reflexive responses to bright daylight.

Neural signals from the rods and cones undergo complex processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Several important features of visual perception can be traced to the retinal encoding and processing of light.

This text uses material from Wikipedia, licensed under CC BY-SA