GABA is a major inhibitory neurotransmitter in the mammalian retina and it acts at many different sites via a variety of postsynaptic receptors. These include GABAA receptors and bicuculline-resistant GABAC receptors. The release of acetylcholine (ACh) is inhibited by GABA and strongly potentiated by GABA antagonists.
View Article and Find Full Text PDFJ Neurophysiol
February 1997
In this report we describe extracellular recordings made from ON and ON-OFF directionally selective (DS) ganglion cells in the rabbit retina during perfusion with agonists and antagonists to acetylcholine (ACh), glutamate, and gamma-aminobutyric acid (GABA). Nicotinic ACh agonists strongly excited DS ganglion cell in a dose-dependent manner. Dose-response curves showed a wide range of potencies, with (+/-)-exo-2-(6-chloro-3pyridinyl)-7-azabicyclo[2.
View Article and Find Full Text PDFWhen intense adapting lights are turned off, the pupil of the turtle, Pseudemys scripta elegans, enlarges. The recovery functions for pupillary dilation have different time constants that are defined by red- and green-sensitive cones and rods as they are affected by prior light adaptation and time in the dark. Pupillary area related to dilation responds over at least a three- to four-fold range.
View Article and Find Full Text PDFJ Neurophysiol
February 1995
1. In this report we describe extracellular recordings made from directionally selective (DS) ganglion cells in the rabbit retina during perfusion with 2-amino-4-phosphonobutyric acid (APB) to block ON channels through the retina. 2.
View Article and Find Full Text PDFRetinal ganglion cells in the turtle, Pseudemys scripta elegans, were examined by intracellular recording with a protocol of stationary and moving lights. Responses were apportioned among OFF, ON, and ON-OFF categories, and directional selectivity. Cells were injected with Neurobiotin, then later conjugated with avidin-horseradish peroxidase in standard procedure.
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