DA neurons in the diencephalon

In adult rats, perikarya of TIDA neurons, originally described as comprising the A12 cell group (Dahlstrom and Fuxe, 1964), are distributed throughout the rostrocaudal extent of the ARC and adjacent periventricular nucleus of the mediobasal hypothalamus. Two populations of TH-containing neurons have been identified based on their neurochemical 

TH-IR neurons in the VL-ARC are larger in size than those in the DM-ARC (Everitt et al. 1986), with dendrites oriented in the mediolateral plane (Chan-Palay et al., 1984 van den Pol et al., 1984) and axons that terminate in the lateral portion of the median eminence (Meister and Hokfelt, 1988). These neurons lack DDC (Everitt et al., 1986 Meister et al., 1988) and do not express DA transporter mRNA as do DA-containing TH-IR neurons in the DM-ARC (Meister and Elde, 1993). Since these DOPAergic neurons do not synthesize or release DA under normal conditions their role in the regulation of prolactin secretion is unknown. In contrast to the DM-ARC, the rostrocaudal distribution 

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