Question

In: Anatomy and Physiology

Draw graphs showing the effects on action potentials in a postsynaptic cell of effective doses for...

Draw graphs showing the effects on action potentials in a postsynaptic cell of effective doses for each of the listed toxins. Assume that the cell is normally brought to threshold by the stimuli applied to its inputs, so that any abnormality is due to the toxin.
1. curare (prevents receptor from binding neurotransmitter)
2. botulinum toxin (prevents neurotransmitter release)

Solutions

Expert Solution

Curare is classified as a neuromuscular blocking agent. It is an example of a non depolarizing muscle relaxant that blocks the nicotinic acetylcholine receptor(nAchR) , one of the two types of acetylcholine (ACh) receptors at the neuro muscular junction.Curare affects the stimulus ( excitatory post synaptic potential, EPSP) which normally leads to the initiation of the muscle action potential.An animal that is poisoned with curare will asphyxiate because the process of neuro muscular transmission at respiratory muscles will be blocked.

In simple words, Curare allows the action potential to form but cannot pass between nerve to muscle.Curare binds to acetylcholine binding sites on post synaptic cell membrane which prevents acetylcholine from acting.Below is the image of a graphical representation of a normal action potential.

Below is the image for graphical representation of action potential affected by curare.The graphical representation indicates the lower rate of action potential taking place due to the curare toxin that prevents acetylcholine from acting.

2. Botulinum neurotoxin A is the most toxic protein known.They enter nerve terminals and decrease the number of acetylcholine containing vesicles released into the synaptic cleft,without affecting acetylcholine synthesis or action potential conduction in the motor nerve. It acts by binding presynaptically to high affinity recognition sites on nerve terminals and decreasing the release of acetylcholine , causing a neuro muscular blocking affect.It entirely blocks transmitter release from motor nerve conduction and causes an end plate potential.Below graph determines the end plate potential after affected by botulinum toxin.

End plate potentials in mV. A& C are weakend end potentials in a muscle to elicit an action potential.The end plate potential C is is caused by botulinum toxin that decreases end plate releases of acetylcholine, too weak to elicit a muscle action potential.

Hope the answer was helpful.

Thanks....................


Related Solutions

1) Which of the following is/are true for both graded potentials and action potentials? a. Effective...
1) Which of the following is/are true for both graded potentials and action potentials? a. Effective for communicating over long distances b. Initiated by transmembrane channel proteins c. Exhibit relative and absolute refractory periods d. both a) and b) are correct, and c) is incorrect e. a), b) and c) are all correct 2) Which of the following statements about Ion channel activity during the action potential is/are correct? a. At the peak of an action potential, Na+ channel activation...
Describe and illustrate the action potentials in a contractile ventricular myocardial cell and a cardiac nodal...
Describe and illustrate the action potentials in a contractile ventricular myocardial cell and a cardiac nodal cell. Show how the ANS can affect the nodal cell action potential. Physiology
Answer in at least one paragraph for each question. 1. Draw graphs showing a) a thermocline...
Answer in at least one paragraph for each question. 1. Draw graphs showing a) a thermocline representing tropical areas, b) a halocline representing an area with high precipitation, and c) a pycnocline representing any area you want. Don’t forget to specify which drawing is which and label the axes. 2. How is heat transferred from the tropics to the poles? Explain. 3. What is the Coriolis effect, why does it occur, and how does it influence atmospheric circulation?
Draw graphs showing a perfectly competitive firm and industry in the long-run equilibrium. a. How do...
Draw graphs showing a perfectly competitive firm and industry in the long-run equilibrium. a. How do you know that the industry is in long-run equilibrium? Long-run when quantity demanded=quantity supplied, no entry and not exit as firms are breaking even. (Which holds true when the P=ATC) b. Suppose that there is an increase in demand for this product. Show and explain the short-run adjustment process for both the firm and the industry. Market demand curve shifts to the right. Equilibrium...
25. Draw a graph showing the short- and long-run effects of an increase in the money...
25. Draw a graph showing the short- and long-run effects of an increase in the money supply.
Drag the labels onto the flowchart to indicate the sequence of events that occurs in the presynaptic cell (orange background) and the postsynaptic cell (blue background) after an action potential reaches a chemical synapse.
Drag the labels onto the flowchart to indicate the sequence of events that occurs in the presynaptic cell (orange background) and the postsynaptic cell (blue background) after an action potential reaches a chemical synapse.
Draw two figures, one figure showing the arrangement of the various cell types found in xylem...
Draw two figures, one figure showing the arrangement of the various cell types found in xylem tissue of angiosperms. Show how they are stacked and packed with soft and strong support cells. In the xylem figure include: 4 vessel element cells (label perforations and pits), 3 parenchyma, 5 sclerenchyma fiber cells. In the second figure show of the various cell types found in phloem tissue. In the phloem tissue figure include: 4 sieve tube cells, 4 companion cells, 3 parenchyma...
Write out the overall cell reaction occurring in the following voltaic cells. Draw a diagram (with two beakers) showing appropriate metals and solution contents.
a) Write out the overall cell reaction occurring in the following voltaic cells. Draw a diagram (with two beakers) showing appropriate metals and solution contents. Write the appropriate half reactions. Label the anode and the cathode and show the direction of electron flow. Cd(s) | Cd2+(aq) || Ag+(aq) | Ag(s)           An electrochemical cell is composed of a silver electrode in a 0.025 M Ag+ solution and a cadmium electrode into a 0.15 M Cd2+ solution....
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT