Alpha-2A adrenergic receptor

The alpha-2A adrenergic receptor (α_2A adrenoceptor), also known as ADRA2A, is an α₂ adrenergic receptor, and also denotes the human genome encoding it.

Receptor

α₂ adrenergic receptors include 3 highly homologous subtypes: α_2A, α_2B, and α_2C. These receptors have a critical role in regulating neurotransmitter release from sympathetic nerves and from adrenergic neurons in the central nervous system. Studies in mice revealed that both the α_2A and α_2C subtypes were required for normal presynaptic control of transmitter release from sympathetic nerves in the heart and from central noradrenergic neurons; the α_2A subtype inhibited transmitter release at high stimulation frequencies, whereas the α_2C subtype modulated neurotransmission at lower levels of nerve activity.

Gene

This gene encodes α_2A subtype and it contains no introns in either its coding or untranslated sequences.

Role in central nervous system

Although the pre-synaptic functions of α_2A receptors have been a major focus (see above), the majority of α₂ receptors in the brain are actually localized post-synaptically to noradrenergic terminals, and therefore aid in the function of norepinephrine. Many post-synaptic α_2A receptors have important effects on brain function; for example, α_2A receptors are localized on prefrontal cortical neurons where they regulate higher cognitive function.

Ligands

Agonists

• Clonidine
• Lofexidine
• Dexmedetomidine
• Guanfacine

Antagonists

• Asenapine
• BRL-44408
• Clozapine
• Lurasidone
• Mianserin
• Mirtazapine
• Paliperidone
• Risperidone
• Yohimbine

See also

• Adrenergic receptor