Author(s): Peter Hitchcock, PH.D., 2009 License: Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution–Non-commercial–Share Alike 3.0 License: http://creativecommons.org/licenses/by-nc-sa/3.0/
We have reviewed this material in accordance with U.S. Copyright Law and have tried to maximize your ability to use, share, and adapt it. The citation key on the following slide provides information about how you may share and adapt this material. Copyright holders of content included in this material should contact [email protected] with any questions, corrections, or clarification regarding the use of content. For more information about how to cite these materials visit http://open.umich.edu/education/about/terms-of-use. Any medical information in this material is intended to inform and educate and is not a tool for self-diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. Please speak to your physician if you have questions about your medical condition. Viewer discretion is advised: Some medical content is graphic and may not be suitable for all viewers.
Citation Key for more information see: http://open.umich.edu/wiki/CitationPolicy
Use + Share + Adapt
Make Your Own Assessment
Creative Commons – Attribution License
Creative Commons – Attribution Share Alike License
Creative Commons – Attribution Noncommercial License
Creative Commons – Attribution Noncommercial Share Alike License
GNU – Free Documentation License
Creative Commons – Zero Waiver
Public Domain – Ineligible: Works that are ineligible for copyright protection in the U.S. (USC 17 § 102(b)) *laws in your jurisdiction may differ
Public Domain – Expired: Works that are no longer protected due to an expired copyright term.
Public Domain – Government: Works that are produced by the U.S. Government. (USC 17 § 105)
Public Domain – Self Dedicated: Works that a copyright holder has dedicated to the public domain.
Fair Use: Use of works that is determined to be Fair consistent with the U.S. Copyright Act. (USC 17 § 107) *laws in your jurisdiction may differ Our determination DOES NOT mean that all uses of this 3rd-party content are Fair Uses and we DO NOT guarantee that your use of the content is Fair. To use this content you should do your own independent analysis to determine whether or not your use will be Fair.
{ Content the copyright holder, author, or law permits you to use, share and adapt. }
{ Content Open.Michigan believes can be used, shared, and adapted because it is ineligible for copyright. }
{ Content Open.Michigan has used under a Fair Use determination. }
Retina and Visual System
M1 – CNS Sequence Peter Hitchcock, Ph.D.
Winter, 2009
The topic of today’s lecture is the central visual pathways. I. anatomy of the eye II. laminar and cellular anatomy of the retina III. regional specializations of the retina IV. central visual pathways V. visual association cortex VI. subcortical projections of ganglion cell axons
circadian rhythms pupilary light reflex
VI. visual information processing
Schematic diagram of the eye.
Hanes. Fundamental Neuroscience. Churchill Livingstone, 2002. 2nd ed.
retinal pigmented epithelium photoreceptor layer
ONL; photoreceptor nuclei
INL; horizontal, bipolar ‘ and amacrine cell nuclei
ganglion cell layer
optic fiber layer
outer plexiform layer
inner plexiform layer
inner limiting membrane
outer limiting membrane
The human retina has 10 layers
light information
Source Undetermined
c - cones r-rods b-bipolar cells h-horizontal cells a-amacrine cells g-ganglion cells
The retina consists of a direct pathway, photoreceptors - bipolar cells - ganglion cells. Information in the direct pathway is modified by horizontal and amacrine cells.
Gray’s Anatomy
Photoreceptors and processes of the RPE interdigitate, but form no specialized junctions. Functions of RPE: phagocytose photoreceptors transport and store Vit. A recycle photopigments absorb stray light regulate fluid levels in the sub-retinal space Retinal detachment occurs when fluid accumulates in the space between the retina and RPE and separates the retina from the RPE. This space was part of the third ventricle in the embryonic brain.
Image of photoreceptors
removed
Müller cells are a specialized type of radial glia Müller cells help maintain ionic balances within the extracellular spaces in the retina. They also form the inner and outer limiting membranes
Images of Muller cells
removed
The two classes of photoreceptors divide visible light into two domains: intensity and wavelength
Rods – dim light, monochromatic
Cones – bright light, 3 wavelength sensitive subgroups
There are several inherited diseases that result in death of photoreceptors, e.g, retinitis pigmentosa, age-related macular degeneration.
R. Young, wikipedia
Absorption spectra for rod and The 3 classes of cone photoreceptors
Hanes. Fundamental Neuroscience. Churchill Livingstone, 2002. 2nd ed.
Fundus photograph of living, human retina illustrating the vasculature, fovea and optic nerve head (disc)
macula (lutea)
fovea
Regional specializations in the retina.
Source Undetermined
sclera
RPE photoreceptors
ONL INL IPL GCL
The fovea is an pit (excavation) in the retina, wherein the inner layers are dis- placed laterally.
RPE, retinal pigmented epithelium; ONL, outer nuclear layer; INL, inner nuclear layer IPL, inner plexiform layer; GCL, ganglion cell layer
Source Undetermined
The fovea contains cone photoreceptors only (no rods) at an extremely high density.
% photorecptors?
cones - 5% rods - 95% Hanes. Fundamental Neuroscience. Churchill Livingstone, 2002. 2nd ed.
Density distribution of photoreceptors in the retina along a line passing through the fovea and optic disc.
Source Undetermined
optic nerve head
Source Undetermined
optic nerve head
lamina cribrosa
blood vessels
optic fiber layer
retina
Source Undetermined
Find your blind spot! Using the diagram below, fixate on the star, close your left eye and hold the figure about 1.5 feet from your face. When the filled circle disappears, its image is on your blind spot.
Frisko, wikimedia commons
Connections from the retina into the hypothalamus diencephalon and midbrain (only 4 will be described)
Image of visual system
connections removed
optic nerve
optic chiasm
optic tract
optic radiations
(Meyer’s loop)
primary visual cortex (area 17; striate cortex)
midbrain (superior colliculus & pre-tectum)
hypthalamus
lateral geniculate nuc.
Source Undetermined
Meyer’s loop N T T N
Cross section through optic chiasm
L
L
L
-lower retina (superior visual fields) -loop (Meyer’s)
-lingual gyrus
T T N
cuneate gyrus
lingual gyrus
N
Source Undetermined
parieto-occipetal fissure
calcarine sulcus
inferior lip
superior lip
CC
Most of primary visual cortex, area 17, lies on the medial wall of the occipital lobe
(cuneate gyrus)
(lingual gyrus)
Source Undetermined
vertical meridian
fovea
periphery fovea
lower vertical meridian
upper vertical meridian
Source Undetermined
Gray’s Anatomy
area 17 flattened and viewed from the surface, illustrating the complete pattern of ocular dominance columns
L=left eye R=right eye
Source Undetermined
These two regions are sometimes referred as the ventral stream (what is it?) and a dorsal stream (where is it?).
Source Undetermined
Cortical lesions in ventral or dorsal stream produce unique perceptual deficits
Source Undetermined
Source Undetermined
Source Undetermined
Additional Source Information for more information see: http://open.umich.edu/wiki/CitationPolicy
Slide 5: Hanes. Fundamental Neuroscience. Churchill Livingstone, 2002. 2nd ed. Slide 6: Source Undetermined Slide 7: Gray’s Anatomy Slide 10: R. Young, Wikipedia, http://en.wikipedia.org/wiki/File:Rod_cone_cells.jpg, PD-SELF Slide 11: Hanes. Fundamental Neuroscience. Churchill Livingstone, 2002. 2nd ed. Slide 12: Source Undetermined Slide 13: Source Undetermined Slide 14: Hanes. Fundamental Neuroscience. Churchill Livingstone, 2002. 2nd ed. Slide 15: Source Undetermined Slide 16: Source Undetermined Slide 17: Source Undetermined Slide 18: Frisko, Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Blind_spot_test.svg, PD-SELF Slide 20: Source Undetermined Slide 21: Source Undetermined Slide 22: Source Undetermined Slide 23: Gray’s Anatomy; Source Undetermined Slide 24: Source Undetermined Slide 25: Source Undetermined Slide 26: Source Undetermined Slide 27: Source Undetermined Slide 28: Source Undetermined