Final answer:
The correct answer is c) GABA plays a role in mood regulation. GABA is the main inhibitory neurotransmitter in the CNS and contributes to mood regulation by hyperpolarizing neurons. After dopamine binds to its receptor, an increase in cAMP is expected, and insulin binds to its receptor before phosphorylation of tyrosine residues.
Step-by-step explanation:
The correct answer to the student's question regarding neurotransmitters and emotions is c) GABA plays a role in mood regulation. The gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central nervous system (CNS), playing a crucial role in mood regulation as well as reducing neural excitability throughout the nervous system. GABA's inhibitory action is due to its ability to cause hyperpolarization of the postsynaptic neurons.
Concerning the related information on neurotransmitters, upon the binding of dopamine to its G-protein-linked receptor, one would expect an increase in the concentration of cyclic adenosine monophosphate (cAMP). This second messenger molecule is essential in the signaling pathways and helps in transmitting the effects of dopamine after it binds to its receptor.
Before the phosphorylation of tyrosine residues in the hormone insulin signaling, the insulin binds to a receptor that has intrinsic tyrosine kinase activity. This initial binding is a critical step that will eventually lead to the phosphorylation of specific tyrosine residues on the intracellular part of the receptor.