During excitatory synaptic transmission, the electrical signal carried along the axon of a presynaptic neuron causes the release of neurotransmitters into the synapse and its sub- sequent reception by receptors on the postsynaptic neurons. The activation of receptors on the postsynaptic neurons then triggers the generation of the new action potential in that neuron. Both chemical and electrical neuronal signals are mediated by the movement of ions across the neuronal membrane. Which of the following correctly describes the movement of ions across neuronal membranes as an action potential is conducted down the neuron?

You have a neural system with three neurons; two presynaptic (PS1 and PS2) and one postsynaptic (Post). Over a fixed period of time, PS1 and PS2 generate the pattern of action potentials. Both deliver the same pattern. PS1 delivers EPSP to Post and PS2 delivers IPSP to Post. Also present in the system is a chemical that inhibits the binding of PS2's neurotransmitter to Post's receptors. Will Post be likely to produce an action potential in response to this situation?

Which of the following statements are true with regards to the differences between a neuromuscular junction, and a standard central nervous system (CNS) synapse? Select all that apply. O The neuromuscular junction is a synapse between a neuron (alpha motor neuron) and a muscle fibre. CNS synapses connect two neurons. The graded potential generated by a neuromuscular junction has a much larger voltage than that of a CNS synapse. The structure of the neuromuscular junction ensures that an action potential in the alpha motor neuron always results in an action potential in the post-synaptic muscle fibre. CNS synapses do not guarantee this. The neuromuscular junction always uses Acetylcholine as a neurotransmitter, whereas CNS synapses may use a variety of neurotransmitters depending on their location and function

Dopamine is a neurotransmitter produced by the nervous system that is involved in the pleasure/reward system in the brain. The release of dopamine in response to a stimulus produces feelings of happiness and satisfaction. Cocaine is a type of drug that affects the brain response to dopamine. Usually after dopamine is released into the synaptic cleft, it is quickly re-absorbed into the neuron using dopamine transporters. However, cocaine blocks these transporters which causes dopamine to remain in the synaptic cleft for a long period of time. How would this impact the neuron's ability to communicate? Neurons will produce smaller action potentials because more dopamine is binding to receptors on the neuron, preventing the neuron from reaching the threshold potential Neurons will be under-stimulated because dopamine will bind to receptors and prevent ions from moving into the neuron, preventing electrical signaling Neurons will produce larger action potentials because more dopamine is…