TY  - JOUR
AU  - Graves, Austin
AU  - Iqbal, Haris
AU  - Pierson, Jessica
PY  - 2003/12/17
TI  -  Decreased calcium concentration increases magnitude and time course of facilitation but decreases time course of depression following long-term high frequency stimuli
JF  - Pioneering Neuroscience; Vol 5 (2004)
KW  - 
N2  - Calcium is a ubiquitous second messenger in neurotransmitter release pathways, but the specific mechanisms of its regulation of synaptic plasticity are still a topic of debate. Our study further clarifies the effects of low calcium concentration on the magnitude and time course of initial synaptic facilitation and subsequent depression resulting from long-term high frequency stimulation at the crayfish neuromuscular junction. Our results contradict previous studies that suggest increased levels of pre-synaptic calcium concentration result in increased magnitude and time course of facilitation. These contradictory results may implicate additional roles for calcium, not only as a second messenger, but also as a buffer ion used to shield the surface charge of cells, thus maintaining a high neuronal threshold. Our results agree with the vesicle depletion hypothesis, that lower levels of calcium leads to a decreased time course of depression.
UR  - https://ojs.grinnell.edu/index.php/pnsj/article/view/143