Answer:
This question lacks options, the options are:
a. Presynaptic; Ca2+ ions
b. Postsynaptic; Ca2+ ions.
c. postsynaptic; neurotransmitters
d. presynaptic; neurotransmitters
e. dendritic; neurotransmitters
The correct answer is d. Tetrahydrocannabinol, the active ingredient in marijuana, binds to receptors located in the <u>presynaptic</u> terminals of certain brain neurons. It lowers the likelihood that these neurons will release <u>neurotransmitters</u>
.
Explanation:
Tetrahydrocannabinol is the most abundant cannabinoid in most cannabis varieties and has the most potent psychoactive effect. Conventional neurotransmitters are water-soluble substances stored in small vesicles at the thin ends of the axon (presynaptic terminals). When a neuron generates an impulse by sending an electrical signal along the axon to the presynaptic terminals, the neurotransmitters are released from the vesicles, diffuse through a narrow intercellular space (synaptic cleft) and interact with the receptors on the surface of the recipient neuron (postsynaptic neuron). Cannabinoids cause a decrease in the release of neurotransmitters from the presynaptic terminal through the inhibition of Ca++ channels. This signaling is mediated by the βγ subunit of the G protein. The βγ subunit of the G protein inhibits the Ca channels of type N and P / Q, which are the majority in presynaptic neurons.
