Question

Please fill in the blank.

1. When an action potential moves to a nerve cell’s terminals, ------ ions enter from the extracellular environment through gated channels to promote vesicle movement.

2. ------ are chemicals responsible for the movement of a single across a synapse between two adjacent nerve cells.  

3. Regarding heterotrimeric G protein, the ------- subunit binds to and stimulates adenylyl cyclase (AC).

4. In heterotrimeric G proteins, the ------- and ------- subunits(s) stimulate phospholipase C.

5. The a-subunit of a heterotrimeric G protein is inactive when bound to the molecule called ------.

6. The sheath made of ------ acts like an electrical insulator surrounding the axon of a neuron.

Please answer the following question:

For treatment of ADHD (attention deficit hyperactivity disorder) antidepressants are often prescribed. These drugs often act by increasing the removal rate of neurotransmitters from the synaptic cleft. What effect(s) would this have on the postsynaptic neurons? How might this affect the patient;s behavior? ( Assume an excitatory neurotransmitter is being considered.)

Answer 1

When an action potential moves to a nerve cell’s terminals, --Ca²⁺- ions enter from the extracellular environment through gated channels to promote vesicle movement. Mostly positive (e.g Na⁺, K⁺, Ca²⁺) or negative ions (e.g Cl^- ) will travel through channels that span the membranes.

Neurotransmitters are chemicals responsible for the movement of a single across a synapse between two adjacent nerve cells. When released they bind to the receptors present on the adjacent axon and transmit the signal by activating the signaling pathway.

Regarding heterotrimeric G protein, the G_salpha subunit (G_αs, G_sα) subunit binds to and stimulates adenylyl cyclase (AC).

In heterotrimeric G proteins, the Galpha and Gq subunits(s) stimulate phospholipase C.

The a-subunit of a heterotrimeric G protein is inactive when bound to the molecule called GDP (guanosine diphosphate) They are rendered active when alternately binds to Guanosine triphosphate (GTP).

The sheath made of myelin (a layer of fatty tissue) acts like an electrical insulator surrounding the axon of a neuron.

Antidepressant drugs inhibit the reuptake of neurotransmitters into the presynaptic neuron. The persistent concentration of these neurotransmitters in the synaptic cleft results in increased postsynaptic receptor stimulation and hence in increased postsynaptic neurotransmission.

They can reduce the hyperactive and impulsive behavior of the patient.