TY  - JOUR
AU  - Moca, Eric
AU  - Scott-Nevros, Zoe
AU  - Dancewicz Helmers, John
PY  - 2020
TI  -  Serotonin increases EPSP amplitude by the activation of IP3-gated calcium channels and ryanodine receptors in Procambarus clarkii
JF  - Pioneering Neuroscience; Vol 14 (2014)
KW  - 
N2  -  Serotonin (5-HT) is a neurohormone found to increase the excitatory presynaptic potential (EPSP) amplitudes recorded at the neuromuscular junction of crayfish. Serotonin is believed to cause this EPSP increase by indirectly activating the inositol triphosphate (IP3)-gated calcium channel on the endoplasmic reticulum (ER) in a neuron by producing IP3. Serotonin is also known to indirectly activate ryanodine receptors through a complex, not yet understood secondary messenger system as well. Our hypotheses were that serotonin would increase overall EPSP amplitude, that the two inhibitors separately would significantly lower EPSP amplitudes, and that both inhibitors added at once would produce an additive effect that seemingly negates the effect of serotonin on EPSP amplitudes. From our experiments, we found that serotonin affects both IP3-gated calcium channel and the ryanodine receptors, by eliciting internal calcium release through both pathways. Through electrophysiology, we saw that the addition of serotonin does, indeed, increase the EPSP at the neuromuscular junction of a crayfish deep extensor muscle cell. We also found that by blocking the aforementioned receptors, the effects of serotonin would be negated, resulting in an EPSP even lower than the EPSP observed in our first control, a basic crayfish saline solution. Addition of 100 μM 2-Aminoethoxydiphenyl borate, 2-APB, blocked the IP3 receptors and decreased the observed EPSP; addition of 10 μM Dantrolene blocked the ryanodine receptors and also decreased the observed EPSP. In conjunction, the two chemicals resulted in a miniscule EPSP. 
UR  - https://ojs.grinnell.edu/index.php/pnsj/article/view/493