Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 61 - 62 of 62

Full-Text Articles in Medicine and Health Sciences

Removal Of Extracellular Chloride Suppresses Transmitter Release From Photoreceptor Terminals In The Mudpuppy Retina., Wallace B. Thoreson, R . F. Miller May 1996

Removal Of Extracellular Chloride Suppresses Transmitter Release From Photoreceptor Terminals In The Mudpuppy Retina., Wallace B. Thoreson, R . F. Miller

Journal Articles: Ophthalmology

Removal of extracellular Cl- has been shown to suppress light-evoked voltage responses of ON bipolar and horizontal cells, but not photoreceptors or OFF bipolar cells, in the amphibian retina. A substantial amount of experimental evidence has demonstrated that the photoreceptor transmitter, L-glutamate, activates cation, not Cl-, channels in these cells. The mechanism for Cl-free effects was therefore reexamined in a superfused retinal slice preparation from the mudpuppy (Necturus maculosus) using whole-cell voltage and current clamp techniques. In a Cl-free medium, light-evoked currents were maintained in rod and cone photoreceptors but suppressed in horizontal, ON bipolar, and OFF bipolar cells. Changes …


Actions Of (1s,3r)-1-Aminocyclopentane-1,3-Dicarboxylic Acid (1s,3r-Acpd) In Retinal On Bipolar Cells Indicate That It Is An Agonist At L-Ap4 Receptors., Wallace B. Thoreson, R. F. Miller Jun 1994

Actions Of (1s,3r)-1-Aminocyclopentane-1,3-Dicarboxylic Acid (1s,3r-Acpd) In Retinal On Bipolar Cells Indicate That It Is An Agonist At L-Ap4 Receptors., Wallace B. Thoreson, R. F. Miller

Journal Articles: Ophthalmology

Metabotropic glutamate receptors (mGluRs) include receptors sensitive to L-2-amino-4-phosphonobutyrate (L-AP4) and 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD). To determine whether 1S,3R-ACPD is an agonist at retinal L-AP4 receptors, whole cell voltage clamp recordings were obtained from mudpuppy ON bipolar cells in a superfused retinal slice and L-AP4 and 1S,3R-ACPD were bath applied. Both compounds evoked similar outward currents which reversed near 0 mV and were accompanied by an increased input resistance. Responses to both agonists washed out in parallel suggesting they act through the same second messenger pathway(s). Inhibitors of cGMP-PDE activity suppressed responses to both L-AP4 and 1SR,3RS-ACPD, suggesting that both compounds …