Endogenous trace amines (TAs) of unknown biological function are
structurally related to classic monoaminergic neurotransmitters and found at
low concentrations in the mammalian brain. Their recently discovered group of
G protein-coupled receptors, trace amine-associated receptors (TAARs), may
represent putative targets not only for trace and other amines but also for a
variety of monoaminergic compounds, including amphetamines and monoamine
metabolites. The trace amine-associated receptor 1 (TAAR1), which is in part
associated with the monoaminergic neuronal circuitry controlling various
functions, including movement, is the best characterized of the class,
although little is known about its regulation and function. Here we review the
pharmacology and biochemical properties of the TAAR1 and its physiological
functions as revealed in studies involving knockout mice lacking this
receptor. Potential therapeutic applications of future selective TAAR1
agonists and antagonists are also discussed. Although understanding of biology
and functions mediated by other TAARs is still in its infancy, it is expected
that further characterization of the functional roles and biochemical
properties of TAARs and identification of endogenous and exogenous ligands
will eventually promote these receptors as an attractive class of targets to
correct monoaminergic processes that could be dysfunctional in a host of
disorders of brain and periphery