Access the full text.
Sign up today, get DeepDyve free for 14 days.
References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.
Annual Reviews www.annualreviews.org/aronline NEUROTRANSMITTER RELEASE mouth of the channel and the calcium sensor for vesicle fusion is 4 0 nm, diffusion models predict that [Caz+]at the sensor would rise within microseconds to levels approaching 100 pM or higher. Similar concentrations can also be achieved at somewhat greater distances if calcium channels form clusters rm that allow summation of the calcium contributions f o individual channels. Because microdomains of high Caz+are so tiny, conventional calcium imaging techniques are unable to detect them. However, Llinhs et a1 (1992) were able to visualize microdomains directly in the squid giant synapse by injecting into the presynaptic terminal a calciumdependent photoprotein. n-aequorin-J, which has reduced sensitivity to Ca*+.During presynaptic action potentials, punctate flashes of light were observed, localized to regions that probably correspond to presynaptic active zones. Because n-aequorin-J produces light only at high concentrations of Caz+,the light flashes correspond to regions where action potentials elevated [CaZ+],to levels estimated by Llinhs et a1 (1992) to exceed 100 pM. CALCIUM DEPENDENCE OF EXOCYTOSIS IN SYNAPTIC TERMINALS Several lines of evidence indicate that the calcium concentration necessary to drive exocytosis in synaptic terminals corresponds to the high levels expected near the inner mouth of open
Annual Review of Neuroscience – Annual Reviews
Published: Mar 1, 1996
Read and print from thousands of top scholarly journals.
Already have an account? Log in
Bookmark this article. You can see your Bookmarks on your DeepDyve Library.
To save an article, log in first, or sign up for a DeepDyve account if you don’t already have one.
Copy and paste the desired citation format or use the link below to download a file formatted for EndNote
Access the full text.
Sign up today, get DeepDyve free for 14 days.
All DeepDyve websites use cookies to improve your online experience. They were placed on your computer when you launched this website. You can change your cookie settings through your browser.