Facilitation at single release sites of a sympathetic neuroeffector junction in the mouse.
AUTOR(ES)
Blakeley, A G
RESUMO
Electrophysiological techniques were used to observe the release of transmitter from one or a few release sites of the sympathetic neuroeffector junction of the mouse vas deferens. Release produces transient accelerations of the depolarizing phase of the excitatory junction potential, known as 'discrete events'. Discrete events associate into families at a constant latency and peak time, but vary in amplitude between a few preferred values. As facilitation develops there is a decrease in the frequency of small members of families and an increase in the frequency of large members, a change in apparent 'quantal content'. A similar change in amplitude distribution occurs when the [Ca]o is raised. The alpha-adrenoceptor antagonist yohimbine increases quantal content when facilitation has developed, but has no significant effect on unfacilitated discrete event amplitude unless the [Ca]o is below 2.0 mM. The alpha-adrenoceptor agonist clonidine reduces facilitated and unfacilitated quantal content under all conditions examined.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1199323Documentos Relacionados
- Electrical activity at the sympathetic neuroeffector junction in the guinea-pig vas deferens.
- Time course of transmitter action at the sympathetic neuroeffector junction in rodent vascular and non-vascular smooth muscle.
- A comparison of cell proliferation at different sites within the large bowel of the mouse.
- Factors influencing an increase in spontaneous transmitter release by hypoxia at the mouse neuromuscular junction.
- Neostigmine increases the size of subunits composing the quantum of transmitter release at mouse neuromuscular junction.