What would be the effect of increased (or decreased) concentration of extracellular Ca2+ on the function of the presynaptic cell? How would you assess this effect experimentally?

3. (3pts) Chelators are compounds that bind tightly to specific ions and prevent them from eliciting a biochemical effect. The drug BAPTA is a chelator of Ca2+ ions. How would injection of BAPTA into a presynaptic neuron affect postsynaptic cells? a. Nothing would happen because postsynaptic potentials are due to Na+, K+ and Cl- ion mediated currents. b. The postsynaptic membrane potentials would be more polar when presynaptic cells are stimulated. c. There would be a reduction in postsynaptic currents upon stimulation of the presynaptic cell. d. Evoked postsynaptic potentials would be normal, but there would be a decrease in the frequency of spontaneous postsynaptic potentials. e. There would not be action potentials fired in presynaptic cells. Page 1 of 6

What are the roles of membrane fluidity in neuron function with regards to metabotropic mechanism(s) that alter membrane potential.

For this question you may use either a neuron or a skeletal muscle fiber (but not both) to answer. In words and/or figures, describe how the binding of a neurontransmitter to its receptor eventually leads to a mechanical event (neurotransmitter release or skeletal muscle contraction). In other words, describe the steps involved in either muscle contraction or nerve conduction. Remember: You may either 1) type your answer here, 2) type in a separate file and upload the file here with or without additional images or 3) write your answer on a separate sheet of paper, scan or screenshot an image of your response and upload the file here.