@article {4228, title = {Electrical synaptic input to ganglion cells underlies differences in the output and absolute sensitivity of parallel retinal circuits.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {31}, year = {2011}, month = {2011 Aug 24}, pages = {12218-28}, abstract = {

Parallel circuits throughout the CNS exhibit distinct sensitivities and responses to sensory stimuli. Ambiguities in the source and properties of signals elicited by physiological stimuli, however, frequently obscure the mechanisms underlying these distinctions. We found that differences in the degree to which activity in two classes of Off retinal ganglion cell (RGC) encode information about light stimuli near detection threshold were not due to obvious differences in the cells{\textquoteright} intrinsic properties or the chemical synaptic input the cells received; indeed, differences in the cells{\textquoteright} light responses were largely insensitive to block of fast ionotropic glutamate receptors. Instead, the distinct responses of the two types of RGCs likely reflect differences in light-evoked electrical synaptic input. These results highlight a surprising strategy by which the retina differentially processes and routes visual information and provide new insight into the circuits that underlie responses to stimuli near detection threshold.

}, keywords = {Animals, Cell Communication, Electrical Synapses, Inbred C57BL, Ionotropic Glutamate, Mice, Neural Pathways, Ocular, Organ Culture Techniques, Photic Stimulation, Receptors, Retina, Retinal Ganglion Cells, Sensitivity and Specificity, Sensory Thresholds, Synaptic Transmission, Vision, Visual Pathways}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.3241-11.2011}, author = {Murphy, Gabe J and Rieke, Fred} } @article {1976, title = {Signals and noise in an inhibitory interneuron diverge to control activity in nearby retinal ganglion cells.}, journal = {Nature Neuroscience}, volume = {11}, year = {2008}, month = {2008 Mar}, pages = {318-26}, abstract = {

Information about sensory stimuli is represented by spatiotemporal patterns of neural activity. The complexity of the central nervous system, however, frequently obscures the origin and properties of signals and noise that underlie these activity patterns. We minimized this constraint by examining mechanisms governing correlated activity in mouse retinal ganglion cells (RGCs) under conditions in which light-evoked responses traverse a specific circuit, the rod bipolar pathway. Signals and noise in this circuit produced correlated synaptic input to neighboring On and Off RGCs. Temporal modulation of light intensity did not alter the degree to which noise in the input to nearby RGCs was correlated, and action potential generation in individual RGCs was largely insensitive to differences in network noise generated by dynamic and static light stimuli. Together, these features enable noise in shared circuitry to diminish simultaneous action potential generation in neighboring On and Off RGCs under a variety of conditions.

}, keywords = {Action Potentials, Amacrine Cells, Animals, Artifacts, Inbred C57BL, Interneurons, Light, Lighting, Mice, Neural Inhibition, Neural Pathways, Ocular, Organ Culture Techniques, Photic Stimulation, Reaction Time, Retinal Bipolar Cells, Retinal Ganglion Cells, Retinal Rod Photoreceptor Cells, Synaptic Transmission, Vision}, issn = {1097-6256}, doi = {10.1038/nn2045}, author = {Murphy, Gabe J and Rieke, Fred} } @article {1980, title = {Network variability limits stimulus-evoked spike timing precision in retinal ganglion cells.}, journal = {Neuron}, volume = {52}, year = {2006}, month = {2006 Nov 9}, pages = {511-24}, abstract = {

Visual, auditory, somatosensory, and olfactory stimuli generate temporally precise patterns of action potentials (spikes). It is unclear, however, how the precision of spike generation relates to the pattern and variability of synaptic input elicited by physiological stimuli. We determined how synaptic conductances evoked by light stimuli that activate the rod bipolar pathway control spike generation in three identified types of mouse retinal ganglion cells (RGCs). The relative amplitude, timing, and impact of excitatory and inhibitory input differed dramatically between On and Off RGCs. Spikes evoked by repeated somatic injection of identical light-evoked synaptic conductances were more temporally precise than those evoked by light. However, the precision of spikes evoked by conductances that varied from trial to trial was similar to that of light-evoked spikes. Thus, the rod bipolar pathway modulates different RGCs via unique combinations of synaptic input, and RGC temporal variability reflects variability in the input this circuit provides.

}, keywords = {Action Potentials, Animals, Dose-Response Relationship, Electric Stimulation, Inbred C57BL, Mice, Models, Neurological, Patch-Clamp Techniques, Photic Stimulation, Radiation, Retinal Ganglion Cells, Synapses, Synaptic Transmission, Visual Pathways}, issn = {0896-6273}, doi = {10.1016/j.neuron.2006.09.014}, author = {Murphy, Gabe J and Rieke, Fred} }