| Center-surround, orientation, and directional properties of turtle retinal horizontal cells. | |
| | |
MedLine Citation:
|
PMID: 3395632 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The spatial transfer functions (STF) of L-type horizontal cells (HC) in turtle retina were measured using drifting sine wave grafting stimuli. Two classes of STF were identified: low-pass and band-pass. A low-pass STF corresponds to a linespread function (LSF) having an excitatory center that attenuates monotonically with distance; a band-pass STF corresponds to a LSF with an excitatory center and an inhibitory surround. Two models of the surround inhibitory mechanism, based on retinal outer plexiform layer (OPL) anatomy, are tested experimentally: surround mediated lateral inhibition and surround modulated self-inhibition. In both types, sign inverting pathways are based on GABA feedback synapses, and sign conserving pathways are based on excitatory synapses and gap junctions. Temperature variation was used to modify synaptic properties and study their effect on STF. The low frequency limb of band-pass STF was most sensitive to temperature changes; its slope increased with decreasing temperature. Synaptic properties were also manipulated pharmacologically. Cutoff frequency of low-pass STF decreased from 0.5 to 0.4 cpmm during exogenous GABA. Picrotoxin (PTX) increases upper cutoff frequency and decreases low frequency limb slope in band-pass STF. Band-pass STF of a ganglion cell (GC) has higher upper and lower cutoff frequencies than a HC in the same retinal region, which corresponds to strong spatial convergence from HC to GC. Orientation sensitivity and directional selectivity were found in some HC. Differences between major and minor response axes in orientation sensitive HC were small, ca. 2 dB; orientation differences in directionally selective HC were also small (ca. 1-2 dB) but directional asymmetry was large (ca. 10-12 dB). |
| | |
Authors:
|
A R Adolph |
Publication Detail:
|
Type: In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: Biological cybernetics Volume: 58 ISSN: 0340-1200 ISO Abbreviation: Biol Cybern Publication Date: 1988 |
Date Detail:
|
Created Date: 1988-09-08 Completed Date: 1988-09-08 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 7502533 Medline TA: Biol Cybern Country: GERMANY, WEST |
Other Details:
|
Languages: eng Pagination: 373-85 Citation Subset: IM |
Affiliation:
|
Eye Research Institute, Boston, MA 02114. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Electric Conductivity Models, Neurological* Picrotoxin / pharmacology Retina / physiology* Retinal Ganglion Cells / drug effects, physiology* Synapses / physiology Turtles gamma-Aminobutyric Acid / pharmacology |
| Grant Support | |
ID/Acronym/Agency:
|
EY-03383/EY/NEI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
124-87-8/Picrotoxin; 56-12-2/gamma-Aminobutyric Acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Recognition of general patterns using neural networks.
Next Document: Diffusion approximation and first-passage-time problem for a model neuron. III. A birth-and-death pr...