TY - JOUR T1 - Histochemical Characterization of the Dorsal Raphe-Periaqueductal Grey Dopamine Transporter Neurons Projecting to the Extended Amygdala JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0121-22.2022 VL - 9 IS - 3 SP - ENEURO.0121-22.2022 AU - Qin Zhao AU - Tetsufumi Ito AU - Chika Soko AU - Yoshie Hori AU - Takafumi Furuyama AU - Hiroyuki Hioki AU - Kohtarou Konno AU - Miwako Yamasaki AU - Masahiko Watanabe AU - Satoshi Ohtsuka AU - Munenori Ono AU - Nobuo Kato AU - Ryo Yamamoto Y1 - 2022/05/01 UR - http://www.eneuro.org/content/9/3/ENEURO.0121-22.2022.abstract N2 - The dorsal raphe (DR) nucleus contains many tyrosine hydroxylase (TH)-positive neurons which are regarded as dopaminergic (DA) neurons. These DA neurons in the DR and periaqueductal gray (PAG) region (DADR-PAG neurons) are a subgroup of the A10 cluster, which is known to be heterogeneous. This DA population projects to the central nucleus of the amygdala (CeA) and the bed nucleus of the stria terminalis (BNST) and has been reported to modulate various affective behaviors. To characterize, the histochemical features of DADR-PAG neurons projecting to the CeA and BNST in mice, the current study combined retrograde labeling with Fluoro-Gold (FG) and histological techniques, focusing on TH, dopamine transporter (DAT), vasoactive intestinal peptide (VIP), and vesicular glutamate transporter 2 (VGlut2). To identify putative DA neurons, DAT-Cre::Ai14 mice were used. It was observed that DATDR-PAG neurons consisted of the following two subpopulations: TH+/VIP– and TH–/VIP+ neurons. The DAT+/TH–/VIP+ subpopulation would be non-DA noncanonical DAT neurons. Anterograde labeling of DATDR-PAG neurons with AAV in DAT-Cre mice revealed that the fibers exclusively innervated the lateral part of the CeA and the oval nucleus of the BNST. Retrograde labeling with FG injections into the CeA or BNST revealed that the two subpopulations similarly innervated these regions. Furthermore, using VGlut2-Cre::Ai14 mice, it was turned out that the TH–/VIP+ subpopulations innervating both CeA and BNST were VGlut2-positive neurons. These two subpopulations of DATDR-PAG neurons, TH+/VIP– and TH–/VIP+, might differentially interfere with the extended amygdala, thereby modulating affective behaviors. ER -