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Mammalian retinal degenerations initiated by gene defects in rods, cones or the retinal pigmented epithelium (RPE) often trigger loss of the sensory retina, effectively leaving the neural retina deafferented. The neural retina responds to this challenge by remodeling, first by subtle changes in neuronal structure and later by large-scale reorganization.(More)
Classifying all of the ganglion cells in the mammalian retina has long been a goal of anatomists, physiologists, and cell biologists. The rabbit retinal ganglion cell layer was phenotyped using intrinsic small molecule signals (aspartate, glutamate, glycine, glutamine, GABA, and taurine) and glutamate receptor-gated 1-amino-4-guanidobutane excitation(More)
Presynaptic gamma-aminobutyrate-immunoreactive (GABA+) profiles were mapped in the cyprinid retina with overlay microscopy: a fusion of electron and optical imaging affording high-contrast ultrastructural and immunocytochemical visualization. GABA+ synapses, deriving primarily from amacrine cells (ACs), compose 92% of conventional synapses and 98% of the(More)
  • R E Marc
  • 1999
Patterns of neuronal excitation in complex populations can be mapped anatomically by activating ionotropic glutamate receptors in the presence of 1-amino-4-guanidobutane (AGB), a channel-permeant guanidinium analogue. Intracellular AGB signals were trapped with conventional glutaraldehyde fixation and were detected by probing registered serial thin sections(More)
Pattern recognition of amino acid signals partitions the cells of the goldfish retina into nine statistically unique biochemical theme classes and permits a first-order chemical mapping of virtually all cellular space. Photoreceptors, bipolar cells, and ganglion cells display a set of unique, nominally glutamatergic type E1, E1+E2, and E4 signatures,(More)
  • R E Marc
  • 1999
Patterns of excitation in populations of retinal bipolar, amacrine, and ganglion cells were mapped by activating alpha-amino-3-hydroxyl-5-methylisoxazole-4-propionic acid (AMPA) and kainate (KA) receptors with KA in the presence of the channel-permeant guanidinium analogue 1-amino-4-guanidobutane (AGB). Registered serial thin sections were probed with(More)
Many photoreceptor degenerations initially affect rods, secondarily leading to cone death. It has long been assumed that the surviving neural retina is largely resistant to this sensory deafferentation. New evidence from fast retinal degenerations reveals that subtle plasticities in neuronal form and connectivity emerge early in disease. By screening mature(More)
Pattern recognition of amino acid signals partitions virtually all of the macaque retina into 16 separable biochemical theme classes, some further divisible by additional criteria. The photoreceptor-->bipolar cell-->ganglion cell pathway is composed of six separable theme classes, each possessing a characteristic glutamate signature. Neuronal aspartate and(More)
Retinal degenerations, regardless of the initiating event or gene defect, often result in a loss of photoreceptors. This formal deafferentation of the neural retina eliminates the intrinsic glutamatergic drive of the sensory retina and, perhaps more importantly, removes coordinated Ca++-coupled signaling to the neural retina. As in other central nervous(More)
Postembedding silver-intensified immunogold procedures reveal high levels of glutamate immunoreactivity in "vertical" elements of the goldfish retina: (1) Red-sensitive and green-sensitive cones display strong glutamate immunoreactivity, especially in their synaptic terminals, but blue-sensitive cones are poorly immunoreactive. (2) All type Mb (on-center)(More)