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Titolo:
Increased spontaneous unit activity and appearance of spontaneous negativepotentials in the goldfish tectum during refinement of the optic projection
Autore:
Kolls, BJ; Meyer, RL;
Indirizzi:
Univ Calif Irvine, Dept Dev & Cell Biol, Irvine, CA 92697 USA Univ Calif Irvine Irvine CA USA 92697 v & Cell Biol, Irvine, CA 92697 USA
Titolo Testata:
JOURNAL OF NEUROSCIENCE
fascicolo: 1, volume: 20, anno: 2000,
pagine: 338 - 350
SICI:
0270-6474(20000101)20:1<338:ISUAAA>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
RETINAL GANGLION-CELLS; REGENERATING VISUOTOPIC MAPS; CROSS-CORRELATION; RETINOTECTAL TRANSMISSION; NERVE REGENERATION; MAMMALIAN RETINA; NEURAL ACTIVITY; SENSITIVITY; RECOVERY; NMDA;
Keywords:
goldfish; retinotectal system; tectum; spontaneous activity; regeneration; visual system; postsynaptic activity;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
45
Recensione:
Indirizzi per estratti:
Indirizzo: Meyer, RL Univ Calif Irvine, Dept Dev & Cell Biol, Biol Sci 2 Bldg, Irvine, CA 92697USA Univ Calif Irvine Biol Sci 2 Bldg Irvine CA USA 92697 A 92697USA
Citazione:
B.J. Kolls e R.L. Meyer, "Increased spontaneous unit activity and appearance of spontaneous negativepotentials in the goldfish tectum during refinement of the optic projection", J NEUROSC, 20(1), 2000, pp. 338-350

Abstract

Spontaneous (not retinally driven) postsynaptic activity was examined during activity-dependent refinement of optic fibers in the goldfish tectum. Unit recordings in vivo and in vitro demonstrated that spontaneous tectal activity increased to 150% of normal during refinement at 1-2 months after optic nerve crush and subsequently returned to baseline over the next month. This increase was not mimicked by long-term denervation indicating an effectspecifically influenced by regenerating fibers. Loss of optic input was also found to induce spontaneous negative potentials (SNPs) rapidly in the tectum. SNPs were negative, monophasic potentials of 70-120 msec duration and20.15 to 21.5 mV amplitude. SNPs occurred with no apparent periodicity at a frequency of similar to 0.3-0.6 Hz. Multiple electrode recordings and depth analysis showed that SNPs were localized events occurring in columnar domains of tectum a few hundred micrometers wide. Cross-correlation analysis revealed that SNPs were strongly correlated with local unit bursting, suggesting SNPs are generated by the summed synaptic and spike currents of coactive cells in small regions of the tectum. SNPs were suppressed by a low concentration of APV indicating they were regulated by NMDA receptors. During regeneration, the number and size of SNPs reached a peak during refinement and subsequently decreased, eventually disappearing. This temporal association with refinement suggests that these patterns of postsynaptic activity may have functional relevance. It is hypothesized that SNPs or the underlying activity that produces them increases the excitability of target cells, allowing the weak, less-convergent input from regenerating axons to drive target groups of cells in the tectum during refinement.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/01/20 alle ore 15:52:07