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Titolo:
Voltage-activated Ca2+ channels and ionotropic GABA receptors localized ataxon terminals of mammalian retinal bipolar cells
Autore:
Pan, ZH;
Indirizzi:
Wayne State Univ, Sch Med, Dept Anat & Cell Biol, Detroit, MI 48201 USA Wayne State Univ Detroit MI USA 48201 & Cell Biol, Detroit, MI 48201 USA
Titolo Testata:
VISUAL NEUROSCIENCE
fascicolo: 2, volume: 18, anno: 2001,
pagine: 279 - 288
SICI:
0952-5238(200103/04)18:2<279:VCCAIG>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
CALCIUM CHANNELS; RAT RETINA; DIFFERENTIAL EXPRESSION; SLICE PREPARATION; TIGER SALAMANDER; GOLDFISH RETINA; CURRENTS; ROD; MOUSE; NEURONS;
Keywords:
rat retina; isolated axon terminal of rod bipolar cell; T-type calcium channel; GABA(A) receptor.; GABA(C) receptor;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
43
Recensione:
Indirizzi per estratti:
Indirizzo: Pan, ZH Wayne State Univ, Sch Med, Dept Anat & Cell Biol, 540 E Canfield Ave, Detroit, MI 48201 USA Wayne State Univ 540 E Canfield Ave Detroit MI USA 48201 48201 USA
Citazione:
Z.H. Pan, "Voltage-activated Ca2+ channels and ionotropic GABA receptors localized ataxon terminals of mammalian retinal bipolar cells", VIS NEUROSC, 18(2), 2001, pp. 279-288

Abstract

A preparation of isolated presynaptic terminals of rat retinal rod bipolarcells was developed. Patch-clamp recordings were performed on the isolatedterminal to determine the type(s) of voltage-activated Ca2+ channels and the contribution of GABA(A) and GABA(C) receptor-mediated currents localizedin the terminal region. Both low-voltage-activated (LVA) and high-voltage-activated (HVA) Ca2+ currents, with properties similar to those found in intact cell recordings, were observed in the isolated terminal recordings. Consistent with previous studies, the HVA Ca2+ currents are L-type since the currents were blocked by low micromolar concentrations of nimodipine and potentiated by BayK 8644. Also, both GABA(A) and GABA(C) receptor-mediated currents were observed in the isolated terminal. The current density of GABA,receptors in the terminal was more than three times higher than that in the soma. In contrast, the current density of GABAA currents between the terminal and the soma was not significantly different. Assessed by 100 muM GABA, the contributions of GABA(A) and GABA(C) receptors to the total GABA-mediated currents at the terminal were comparable. This study directly demonstrates the localization of LVA Ca2+ channels at the axon terminal of mammalian rod bipolar cells, suggesting that LVA Ca2+ channels may play a role in bipolar cell transmitter release. Results of this study also support the notion that both types of ionotropic GABA receptors regulate synaptic transmission in mammalian rod bipolar cells. In addition, this study reports for the first time the feasibility of direct patch-clamp recordings of isolated axon terminals of mammalian retinal bipolar cells. The isolated presynaptic terminal preparation of mammalian retinal bipolar cells could be a valuablesystem for the study of transmitter release in the: central nervous system(CNS).

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 18/01/20 alle ore 21:34:01