Integration Center (integration + center)

Distribution by Scientific Domains


Selected Abstracts


Three-dimensional distribution of no sources in a primary mechanosensory integration center in the locust and its implications for volume signaling

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 15 2010
Daniel Münch
Abstract Nitric oxide (NO) is an evolutionarily conserved mediator of neural plasticity. Because NO is highly diffusible, signals from multiple sources might combine in space and time to affect the same target. Whether such cooperative effects occur will depend on the effective signaling range and on the distances of NO sources to one another and to their targets. These anatomical parameters have been quantified in only few systems. We analyzed the 3D architecture of NO synthase (NOS) expression in a sensory neuropil, the ventral association center (VAC) of the locust. High-resolution confocal microscopy revealed NOS immunoreactive fiber boutons in submicrometer proximity to both the axon terminals of sensory neurons and their postsynaptic target, interneuron A4I1. Pharmacological manipulation of NO signaling affected the response of A4I1 to individual wind-puff stimuli and the response decrement during repetitive stimulation. Mapping NOS immunoreactivity in defined volumes around dendrites of A4I1 revealed NOS-positive fiber boutons within 5 ,m of nearly every surface point. The mean distances between neighboring NOS-boutons and between any point within the VAC and its nearest NOS-bouton were likewise about 5 ,m. For an NO signal to convey the identity of its source, the effective signaling range would therefore have to be less than 5 ,m, and shorter still when multiple boutons release NO simultaneously. The architecture is therefore well suited to support the cooperative generation of volume signals by interaction between the signals from multiple active boutons. J. Comp. Neurol. 518:2903,2916, 2010. © 2010 Wiley-Liss, Inc. [source]


Three-dimensional distribution of NO sources in a primary mechanosensory integration center in the locust and its implications for volume signaling

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 15 2010
Daniel Münch
Abstract Nitric oxide (NO) is an evolutionarily conserved mediator of neural plasticity. Because NO is highly diffusible, signals from multiple sources might combine in space and time to affect the same target. Whether such cooperative effects occur will depend on the effective signaling range and on the distances of NO sources to one another and to their targets. These anatomical parameters have been quantified in only few systems. We analyzed the 3D architecture of NO synthase (NOS) expression in a sensory neuropil, the ventral association center (VAC) of the locust. High-resolution confocal microscopy revealed NOS immunoreactive fiber boutons in submicrometer proximity to both the axon terminals of sensory neurons and their postsynaptic target, interneuron A4I1. Pharmacological manipulation of NO signaling affected the response of A4I1 to individual wind-puff stimuli and the response decrement during repetitive stimulation. Mapping NOS immunoreactivity in defined volumes around dendrites of A4I1 revealed NOS-positive fiber boutons within 5 ,m of nearly every surface point. The mean distances between neighboring NOS-boutons and between any point within the VAC and its nearest NOS-bouton were likewise about 5 ,m. For an NO signal to convey the identity of its source, the effective signaling range would therefore have to be less than 5 ,m, and shorter still when multiple boutons release NO simultaneously. The architecture is therefore well suited to support the cooperative generation of volume signals by interaction between the signals from multiple active boutons. J. Comp. Neurol. 518:2903,2916, 2010. © 2010 Wiley-Liss, Inc. [source]


Spatial representation of odorant structure in the moth antennal lobe: A study of structure,response relationships at low doses

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2003
Jocelijn Meijerink
Abstract How odorant structure and concentration are spatially represented within the primary olfactory integration center, the antennal lobe (AL) or olfactory bulb (OB) in invertebrates and vertebrates, respectively, is currently a topic of high interest. Here, we show the spatial representation of odorant structure in the antennal lobe of the moth Spodoptera littoralis by imaging calcium activity evoked by straight chain aliphatic alcohols and aldehydes at low doses. Activity patterns of a given odor were most similar to compounds with the same functional group, differing in chain length by only one carbon atom. A chain length dependency was present as the most activated glomerulus in the lobe shifted from a medial to a lateral position with increasing chain length of the molecule. Statistical analysis revealed that in both classes of chemicals the chain length of the molecule was represented in a similar way. No topographically fixed domains were observed for any of the classes. However, activity patterns evoked by lower chain length molecules were spatially more distinct than patterns evoked by higher chain length molecules. The number of activated glomeruli for both classes of chemicals increased with increasing chain length to reach a maximum at eight or nine C atoms followed by a decrease as the chain length further increased. J. Comp. Neurol. 467:11,21, 2003. © 2003 Wiley-Liss, Inc. [source]


Visual experience and age affect synaptic organization in the mushroom bodies of the desert ant Cataglyphis fortis

DEVELOPMENTAL NEUROBIOLOGY, Issue 6 2010
Sara Mae Stieb
Abstract Desert ants of the genus Cataglyphis undergo an age-related polyethism from interior workers involved in brood care and food processing to short-lived outdoor foragers with remarkable visual navigation capabilities. The quick transition from dark to light suggests that visual centers in the ant's brain express a high degree of plasticity. To investigate structural synaptic plasticity in the mushroom bodies (MBs),sensory integration centers supposed to be involved in learning and memory,we immunolabeled and quantified pre- and postsynaptic profiles of synaptic complexes (microglomeruli, MG) in the visual (collar) and olfactory (lip) input regions of the MB calyx. The results show that a volume increase of the MB calyx during behavioral transition is associated with a decrease in MG numbers in the collar and, less pronounced, in the lip. Analysis of tubulin-positive profiles indicates that presynaptic pruning of projection neurons and dendritic expansion in intrinsic Kenyon cells are involved. Light-exposure of dark-reared ants of different age classes revealed similar effects. The results indicate that this structural synaptic plasticity in the MB calyx is primarily driven by visual experience rather than by an internal program. This is supported by the fact that dark-reared ants age-matched to foragers had MG numbers comparable to those of interior workers. Ants aged artificially for up to 1 year expressed a similar plasticity. These results suggest that the high degree of neuronal plasticity in visual input regions of the MB calyx may be an important factor related to behavior transitions associated with division of labor. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 408,423, 2010 [source]