It has long been recognized that noradrenaline, the most abundant catecholamine within the visual cortex, plays important roles in modulating the sensitivity of cortical neurons to visual stimuli. However, whether or not these noradrenaline effects are confined to a discrete synaptic specialization or mediated by diffuse modulation of a group of synapses has remained an issue open for debate. T...

We injected tracer into wide regions of visual cortex in the cat to produce retrograde and orthograde labeling in the thalamus, chiefly in the lateral geniculate nucleus and lateral posterior-pulvinar complex (LP-Pulvinar). We used the electron microscope to measure the sizes of orthogradely labeled terminals in thalamus and used these measurements to help determine whether the terminals were "...

We have produced a monoclonal antibody which stains the Müller cells in the region of the photoreceptors, nerve terminals surrounding the horizontal cells, and nerve terminals in the inner plexiform layer in carp, goldfish, and white perch retinas. Electron microscopy showed that the staining in the outer and inner retina was confined to Müller cells and presynaptic terminals, respectively. In ...

The organization of neuronal wiring into layers and columns is a common feature of both vertebrate and invertebrate brains. In the Drosophila visual system, each R7 photoreceptor axon projects within a single column to a specific layer of the optic lobe. We refer to the restriction of terminals to single columns as tiling. In a genetic screen based on an R7-dependent behavior, we identified the...

Substance P-like immunoreactivity (SPLI) was immunohistochemically analyzed in the retinae and optic tecta of Rana pipiens embryos and tadpoles between stages 25 of Shumway (S25) and XXV of Taylor and Kollros (TKXXV). A population of retinal ganglion cell (RGC) somata display SPLI. The number of labeled cell bodies increases in proportion and staining intensity between S25 and TKX and progressi...