Table 5.

Anatomical findings for the DA system in early sensory areas.

Structure	Species	Significance	Reference
V1	Rhesus monkey and rat	Lowest density of dopaminergic innervation across cortical mantle	Brown et al., 1979; Descarries et al., 1987; Lidow et al., 1991
V1	Cynomolgus monkey	TH immunoreactive fibers restricted to layer 1	Berger et al., 1988
V1	Rat	Dopaminergic innervation in infragranular layers and weaker in layer 1	Phillipson et al., 1987
A1	Gerbil	D1 receptors in infragranular layers	Schicknick et al., 2008
A1	Cynomolgus and squirrel monkey	TH immunoreactive fibers in layers 1 and 6	Lewis et al., 1987
S1	Cynomolgus and squirrel monkey	TH immunoreactive fibers in supra- and infragranular layers	Lewis et al., 1987
LGN	Rat	Dopaminergic innervation of all LGN subdivisions	Papadopoulos and Parnavelas, 1990
LGN and MGN	Human	Moderate levels of D2 receptor mRNA	Hurd et al., 2001
Inferior colliculus	Rat and mouse	Innervation by TH immunoreactive fibers	Tong et al., 2005; Nevue et al., 2015
Inferior colliculus	Rat	D2 receptors present at moderate levels	Weiner et al., 1991
Superior colliculus	Rat	D2 receptors present at low levels	Weiner et al., 1991