Table I.

Anatomic substrates of DA functions in gastropod and mammalian nervous systems.

Function	Gastropod nervous system	Mammalian nervous system
Sensation	Cephalic sensory organs (Wyeth and Croll, 2011, Faller et al., 2017; Brown et al., 2018)	Olfactory bulb (Kosaka et al., 1985; Kosaka and Kosaka, 2008; Kiyokage et al., 2010)
Activation	Cerebral-buccal command-like interneurons (Rosen et al., 1991; Narusuye and Nagahama, 2002)	Nigrostriatal projections Howe and Dombeck, 2016; see also Jin and Costa, 2010)
Selection	Aplysia buccal interneurons (B20 & B65) (Teyke et al., 1993; Kabotyanski et al, 1998; Jing and Weiss, 2001)	Nigrostriatal projections (Graybiel, 1995; Mink, 1996; Redgrave et al., 1999; Howard et al., 2017)
Valuation	Aplysia B20; Lymnaea PRN (Jing et al., 2007; Crossley et al., 2018)	VTA projections to ventral striatum (Kroemer et al., 2016)
Association	Pharyngeal DA afferents (Martínez-Rubio et al., 2009; Bédécarrats et al., 2013)	VTA-striatal projections (Graybiel, 2005, 2008)
Coincidence Detection	Pharyngeal DA afferents (Brembs et al., 2002; Reyes et al., 2005; Martínez-Rubio et al., 2009)	VTA-striatal and cortical projections (Levine et al., 1996; Williams and Goldman-Rakic, 1998; Schultz, 2010)

^1.Selected references shown for each function.