Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
MAPPING THE LOCATION OF FUNCTIONAL NICOTINIC AND GAMMA-AMINOBUTYRIC ACID(A) RECEPTORS ON HIPPOCAMPAL-NEURONS
Autore:
ALKONDON M; PEREIRA EFR; ALBUQUERQUE EX;
Indirizzi:
UNIV MARYLAND,SCH MED,DEPT PHARMACOL & EXPT THERAPEUT BALTIMORE MD 21201 UNIV MARYLAND,SCH MED,DEPT PHARMACOL & EXPT THERAPEUT BALTIMORE MD 21201 FED UNIV RIO DE JANEIRO,INST BIOPHYS CARLOS CHAGAS FILHO,LAB MOL PHARM 2 BR-21944 RIO JANEIRO BRAZIL
Titolo Testata:
The Journal of pharmacology and experimental therapeutics
fascicolo: 3, volume: 279, anno: 1996,
pagine: 1491 - 1506
SICI:
0022-3565(1996)279:3<1491:MTLOFN>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHOLINE-ACETYLTRANSFERASE IMMUNOCYTOCHEMISTRY; ALPHA-BUNGAROTOXIN BINDING; CENTRAL-NERVOUS-SYSTEM; ACETYLCHOLINE-RECEPTORS; RAT HIPPOCAMPAL; INITIAL CHARACTERIZATION; DENDRITIC RELEASE; SUBSTANTIA-NIGRA; GRANULE CELLS; CURRENTS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
59
Recensione:
Indirizzi per estratti:
Citazione:
M. Alkondon et al., "MAPPING THE LOCATION OF FUNCTIONAL NICOTINIC AND GAMMA-AMINOBUTYRIC ACID(A) RECEPTORS ON HIPPOCAMPAL-NEURONS", The Journal of pharmacology and experimental therapeutics, 279(3), 1996, pp. 1491-1506

Abstract

To assess the density and distribution of functional nicotinic acetylcholine receptors (nAChRs) and gamma-aminobutyric acid (GABA) receptors on hippocampal neurons, we have combined infrared videomicroscopy with a nanorobotic micromanipulator system and studied the receptor-mediated currents by using the whole-cell patch-clamp technique. Acetylcholine or GABA was applied by pressure ejection onto a small segment of either cell soma or dendrite, and the resulting current was measured in cultured hippocampal neurons by using a whole-cell pipette positioned at the cell soma. Type IA nicotinic currents, sensitive to blockade by methyllycaconitine (1 nM) and alpha-bungarotoxin and associated with alpha 7-subunit-containing nAChRs, type II currents, sensitive to blockade by dihydro-beta-erythroidine (100 nM) subserved by alpha 4 beta2 nAChRs, and GABA-mediated currents were evoked when the agonists were applied to either cell soma or the dendrites. Analysis of the current amplitude with respect to the membrane area covered by the applied agonist provided an estimation of the receptor density along the somato-dendritic axis of the hippocampal neurons. Such analysis revealed: 1) a nonuniform distribution for the receptor types studied; 2) a higher density of nAChR and GABA receptors at the dendrites than at the soma; and 3) an increasing density for both nAChR subtypes with distance from the center of the cell soma, but increasing and then decreasing density for the GABA receptor. Exposure of cultured hippocampal neuronsto colchicine (100 nM for 3 days) produced a dramatic reduction in the dendritic branching, and this morphological feature was associated with a significant decrease in the receptor density, such an effect being more prominent for nAChRs than for GABA receptors. Given the high Ca++ permeability of nAChRs, the dendritic localization of nAChRs suggest that they are involved in modulating the synaptic efficacy at the level of the dendrites.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 11:35:24