Braking dopamine systems: a new GABA master structure for mesolimbic and nigrostriatal functions.
A new mesopontine structure exerting a strong influence on dopamine systems has recently been defined: the tail of the ventral tegmental area/rostromedial tegmental nucleus (tVTA/RMTg). This review presents a neuroanatomical, physiological, and behavioral overview of some of the recent and ongoing research on this brain region and its relationship with dopamine systems. The tVTA/RMTg sends dense GABA projections to VTA and substantia nigra neurons. The inhibitory influence of tVTA/RMTg on dopamine neurons is supported by both neuroanatomical and electrophysiology data. The latter studies also reveal the tVTA/RMTg as a substrate for morphine and cannabinoid action on dopamine cells. In primates, the tVTA/RMTg has been implicated in reward prediction error signals, through a basal ganglia-lateral habenula-tVTA/RMTg-dopamine-basal ganglia circuit. In rodents, the tVTA/RMTg has been shown to play a critical role in aversive behaviors, particularly those involving behavioral inhibition, such as freezing and avoidance. These findings highlight the functional importance of the tVTA/RMTg as a major GABA brake for dopamine systems.
Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67084 Strasbourg, France. mbarrot@inci-cnrs.unistra.fr
Michel
M
Barrot
Susan R
SR
Sesack
François
F
Georges
Marco
M
Pistis
Simon
S
Hong
Thomas C
TC
Jhou
D000818:Animals; D003342:Corpus Striatum / Q000502:physiology*; D004298:Dopamine / Q000502:physiology*; D006801:Humans; D009415:Nerve Net / Q000502:physiology*; D013378:Substantia Nigra / Q000502:physiology*; D017557:Ventral Tegmental Area / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D005680:gamma-Aminobutyric Acid; D004298:Dopamine