Question 10

(Essay)

Figure Q3-6 is from an experiment that helped show that neurotransmitter release is triggered by presynaptic Ca2+. In panel A, the presynaptic membrane potential was clamped at -25mV. Figure Q3-6 is from an experiment that helped show that neurotransmitter release is triggered by presynaptic Ca<sup>2+</sup>. In panel A, the presynaptic membrane potential was clamped at -25mV.   Figure Q3-6 A. How did they know Ca<sup>2+</sup> entered the presynaptic neuron? B. What happened in the postsynaptic neuron? C. In panel B, the presynaptic membrane potential was clamped at -50mV. Why was there no net current during the presynaptic depolarization? D. Why was there a current after the presynaptic potential was clamped back to -70mV? E. What happened to the delay in postsynaptic current with the +50mV presynaptic depolarization? Figure Q3-6
A. How did they know Ca2+ entered the presynaptic neuron?
B. What happened in the postsynaptic neuron?
C. In panel B, the presynaptic membrane potential was clamped at -50mV. Why was there no net current during the presynaptic depolarization?
D. Why was there a current after the presynaptic potential was clamped back to -70mV?
E. What happened to the delay in postsynaptic current with the +50mV presynaptic depolarization?

Answer

There was a large presynaptic, inward Ca...

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