This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
[{'content': 'Increasing the concentration of norepinephrine in adrenergic synapses leads to \nSelect and explain. \nA. Activation of tyrosine hydroxylase, B. Activation of dopa decarboxylase, C. Increased release of norepinephrine, D. Activation of presynaptic Gi (C) coupled receptors', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Classification:- Adrenergic receptors are classified into two types a and b. The a receptors were demonstrated to be present prejunctionally as well. To differentiate these release inhibitory prejunctional a receptors, a subdivision into a1 and a2 was suggested. b receptors were fuher subdivided into b1, b2, beta 3subtypes. Alpha2 receptor is located prejunctionally and inhibits the release of neurotransmitter. Ref:- kd tripathi; pg num:-126,127', 'role': 'assistant'}]