Enables alpha2-adrenergic receptor activity. Involved in several processes, including glucose homeostasis; negative regulation of secretion by cell; and negative regulation of uterine smooth muscle contraction. Located in several cellular components, including axon terminus; neuronal cell body; and plasma membrane. Is active in GABA-ergic synapse and glutamatergic synapse. Is integral component of postsynaptic density membrane and integral component of presynaptic active zone membrane. Used to study anxiety disorder and mental depression. Biomarker of hypertension and type 2 diabetes mellitus. Human ortholog(s) of this gene implicated in attention deficit hyperactivity disorder and type 2 diabetes mellitus. Orthologous to human ADRA2A (adrenoceptor alpha 2A). [provided by Alliance of Genome Resources, Apr 2022]