[ 73 ] Antagonization of the α 2 -adrenergic receptors which function largely as pre-synaptic autoreceptors and heteroreceptors enhances adrenergic and serotonergic neurotransmission , notably central 5-HT 1A receptor -mediated transmission. [ 2 ] [ 70 ] [ 74 ] [ 75 ] [ 76 ] Because of this, mirtazapine has