In vivo imaging of calcium accumulation in fly interneurons as elicited by visual motion stimulation.

AUTOR(ES)

Borst, A

RESUMO

The computation of motion plays a central role in visual orientation. The fly has been successfully used as a model system for analyzing the mechanisms underlying motion detection. Thereby, much attention has been paid to a neuronal circuit of individually identifiable neurons in the third visual ganglion that extracts different types of retinal motion patterns and converts these patterns into specific components of visual orientation behavior. The extended dendritic trees of these large cells are the sites of convergence of numerous spatially distributed local motion-sensitive elements. As is revealed by in vivo microfluorometric imaging, these cells accumulate calcium during activation by visual motion stimulation. The spatiotemporal pattern of calcium distribution shows the following characteristics: (i) calcium accumulation is first spatially restricted to those dendritic branches that are depolarized by the retinotopic input, (ii) during ongoing motion stimulation calcium may also accumulate throughout the cell and, in particular, in regions that do not receive direct synaptic input. These experiments successfully monitor the intracellular distribution of activity-dependent ions in visual interneurons of living animals stimulated by their natural synaptic input.

Documentos Relacionados

• Substance P-mediated slow excitatory postsynaptic potential elicited in dorsal horn neurons in vivo by noxious stimulation.
• Calcium imaging demonstrates colocalization of calcium influx and extrusion in fly photoreceptors
• Lactate rise detected by 1H NMR in human visual cortex during physiologic stimulation.
• Calcium release in skinned muscle fibres of the toad by transverse tubule depolarization or by direct stimulation.
• Dynamic magnetic resonance imaging of human brain activity during primary sensory stimulation.