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Titolo:
Synaptically driven calcium transients via nicotinic receptors on somatic spines
Autore:
Shoop, RD; Chang, KT; Ellisman, MH; Berg, DK;
Indirizzi:
Univ Calif San Diego, Dept Biol 0357, La Jolla, CA 92093 USA Univ Calif San Diego La Jolla CA USA 92093 l 0357, La Jolla, CA 92093 USA Univ Calif San Diego, Dept Neurosci, La Jolla, CA 92093 USA Univ Calif SanDiego La Jolla CA USA 92093 urosci, La Jolla, CA 92093 USA Univ Calif San Diego, Natl Ctr Microscopy & Imaging Res, La Jolla, CA 92093 USA Univ Calif San Diego La Jolla CA USA 92093 ng Res, La Jolla, CA 92093 USA
Titolo Testata:
JOURNAL OF NEUROSCIENCE
fascicolo: 3, volume: 21, anno: 2001,
pagine: 771 - 781
SICI:
0270-6474(20010201)21:3<771:SDCTVN>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHICK CILIARY GANGLION; NEURONAL ACETYLCHOLINE-RECEPTORS; LONG-TERM POTENTIATION; DENDRITIC SPINES; ALPHA-BUNGAROTOXIN; CELL-DEATH; IN-VIVO; TRANSMISSION; SUBUNITS; RESPONSES;
Keywords:
nicotinic; spines; calcium; acetylcholine receptors; ciliary ganglion; alpha 7;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Berg, DK Univ Calif San Diego, Dept Biol 0357, 9500 Gilman Dr, La Jolla, CA 92093 USA Univ Calif San Diego 9500 Gilman Dr La Jolla CA USA 92093 093 USA
Citazione:
R.D. Shoop et al., "Synaptically driven calcium transients via nicotinic receptors on somatic spines", J NEUROSC, 21(3), 2001, pp. 771-781

Abstract

Dendritic spines commonly receive glutamatergic innervation at postsynaptic densities and compartmentalize calcium influx arising from synaptic signaling. Recently, it was shown that a class of nicotinic acetylcholine receptors containing alpha7 subunits is concentrated on somatic spines emanating from chick ciliary ganglion neurons. The receptors have a high relative calcium permeability and contribute importantly to synaptic currents, althoughthey appear to be excluded from postsynaptic densities. Here we show that low-frequency synaptic stimulation of the alpha7-containing receptors induces calcium transients confined to the spines. High-frequency stimulation induces a transient calcium elevation in the spines and a more sustained cell-wide elevation. The high-frequency transient elevation again depends on alpha7-containing receptors, whereas the sustained elevation can be triggeredby other nicotinic receptors and depends on calcium release from internal stores and probably influx through voltage-gated L-type calcium channels aswell. Retrograde axonal stimulation of the neurons at high frequency mimics synaptic stimulation in producing sustained cell-wide calcium increases that depend on L-type channels and release from internal stores, but it doesnot produce calcium transients in the spines. Thus frequent action potentials are sufficient to generate the cell-wide increases, but alpha7-containing receptors are needed for spine-specific effects. Patch-clamp recording indicates that alpha7-containing receptors preferentially desensitize at high-frequency stimulation, accounting for the inability of the stimulation tosustain high calcium levels in the spines. The spatial and temporal differences in the patterns of calcium elevation could enable the neurons to monitor their own firing histories for regulatory purposes.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 10/07/20 alle ore 11:59:55