Plasticity in exocytosis revealed through the effects of repetitive stimuli affect the content of nanometer vesicles and the fraction of transmitter released

• Electrochemical techniques with disk and nano-tip electrodes, together with calcium imaging, were used to examine the effect of short-interval repetitive stimuli on both exocytosis and vesicular content in a model cell line. We show that the number of events decreases markedly with repeated stimuli suggesting a depletion of exocytosis machinery. However, repetitive stimuli induce a more stable fusion pore, leading to an increased amount of neurotransmitter release. In contrast, the total neurotransmitter content inside the vesicles decreases after repetitive stimuli, resulting in a higher average release fraction from each event. We suggest a possible mechanism regarding a link between activity-induced plasticity and fraction of release.

Subject headings

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

Keyword

amperometry

vesicle impact electrochemical cytometry

exocytosis

repetitive stimuli

plasticity

protein-kinase-c

activity-dependent potentiation

catecholamine

release

quantal size

fusion pore

chromaffin

cells

pheochromocytoma

activation

dynamin

Science & Technology - Other Topics

Publication and Content Type

ref (subject category)

art (subject category)