QUESTION 5 When a GABAA ionotropic receptor is stimulated by GABA in a developin
ID: 193324 • Letter: Q
Question
QUESTION 5 When a GABAA ionotropic receptor is stimulated by GABA in a developing neuron, which ions flow through its channel, and what effect docs this have on tiho postsynaptic cell? CI, which hyperpolarizes the postsynaptic cell CI, which depolarizes the postsynaptic cell Nat, which depolarizes the postsynaptic cell K*, which hyperpolarizes the postsynaptic cell QUESTION6 Which neuronal mechanism increases the production of catecholamine neurotransmitters? Co-activation of metabotropic and AMPA glutamate Dimerization of tyrosine kinase receptors Activation of the ras cascade Phosphorylation of tyrosine hydroxylase QUESTION 7 Which statement describes a possible outcome for a neurotransmitter after release into the synaptic cleft? Activation of G-protein-coupled receptor on postsynaptic cell Modulation by an enzyme, increasing its efficiency Uptake into postsynaptic cell via endocytosis Reuptake into postsynaptic terminal via transporter proteinsExplanation / Answer
5) Exoplasmic domain of ligand gated receptor possess a neurotramsmitter binding site. Binding of neurotransmitter cause an imediate conformational change that open the channel portion of the protein allwing ion to cross the membrane and causing the membrane potental to change within 0.1-2 milli sec. Binding of neurotransmitter to activating receptor open the ion channel for Na+ or K+ and cause depolarization of postsynaptic membrane but here ligand GABA bind to inhibitory receptor open a Cl- channel leading to hyperpolarization of postsynaptic plasma membrane. So, the answer is A
6) ans is D. tyrosine hydroxylase is a phosphoprotein and major enzyme in synthesis of catecholamine. cAMP dependent phosphorylation of tyrosine hydroxylase accelerate catecholamine biosynthesis.
7) ans is D) reuptake into postsynaptic terminal via a transporter protein.