Sensory information is represented in the brain by the joint activity of large groups of neurons. Recent studies have shown that, although the number of possible activity patterns and underlying interactions is exponentially large, pairwise-based models give a surprisingly accurate description of neural population activity patterns. We explored the architecture of maximum entropy models of the ...

During the early postnatal period in the hamster, the retinal ganglion cell layer grows, establishes its central connections, and undergoes substantial cell loss. In this study, we describe the development of the retinal ganglion cell layer with particular attention to the creation of local specializations in cell density. Changes in the number and spatial distribution of cells identified by a ...

The sensitivity to spatial contrast patterns of single retinal ganglion cell axons and neurons in the A-layers of the dorsal lateral geniculate nucleus (LGNd) was measured in 4 1/2- and 6 1/2-week-old kittens and adult cats. Drifting sinusoidal grating stimuli were presented at 6-12 spatial frequencies to obtain spatial contrast sensitivity functions (SCSFs). The SCSFs were normalized for the p...

The goal of this work was to describe the interaction of sensitivity regulation and temporal dynamics through the primate retina. A linear systems model was used to describe the temporal amplitude sensitivity at different retinal illuminances. Predictions for the primate H1 horizontal cell were taken as the starting point. The H1 model incorporated an early time-dependent stage of sensitivity r...

It has been hypothesized that synaptic pruning precedes retinal ganglion cell degeneration in glaucoma, causing early dysfunction to retinal ganglion cells. To begin to assess this, we studied the excitatory synaptic inputs to individual ganglion cells in normal mouse retinas and in retinas with ganglion cell degeneration from glaucoma (DBA/2J), or following an optic nerve crush. Excitatory syn...

Glaucoma, a neurodegenerative disease, has varied pathogenesis scenario, including elevated intraocular pressure (IOP), and hypoxic conditions in the retina. Consequently, degenerating optic axons at nerve head are observed clinically when extensive damage already occurred. Following IOP, changes retinal ganglion cells lead to apoptosis immediately followed by degeneration of their axons. Degra...

The function of the retina is to transform the pattern of the visual world impinging on the photoreceptors into patterns of neural activity at the ganglion cells. These patterns are then further processed by higher centers for perception. The retinal transformations appear to take place in a series of stages: the initial neural pattern at the photoreceptors is transformed by interactions at the...