Gasbarri A, Verney C, Innocenzi R, Campana E, Pacitti C
Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, Italy.
Brain Res. 1994 Dec 30;668(1-2):71-9. doi: 10.1016/0006-8993(94)90512-6.
A major mesolimbic projection towards the hippocampal formation (HF) has been extensively described, but no clear evidence of its dopaminergic content has been demonstrated. In order to evaluate the percentage of dopaminergic (DA) cells of ventral tegmental area (VTA-A10) and adjacent substantia nigra (SN-A9) projecting to the HF, the retrograde neuronal tracer technique was combined with the tyrosine hydroxylase (TH) immunocytochemistry. Fluoro-gold (FG) was injected in several areas (subiculum, CA1, CA3, dentate gyrus) of either septal and temporal HF. Sections containing retrogradely FG labeled neurons were either mounted directly as controls or incubated with TH antiserum and revealed with rhodamine. The quantitative evaluation of retrogradely labeled and TH-IR stained cells showed that both VTA and SN projections towards the HF are partially (15-18%) dopaminergic. Ten percent of the DA neurons of the VTA projected to contralateral HF, whereas none did in the SN. In conclusion, the temporal HF (mainly subiculum and adjacent CA1) appears to receive the main DA afferents from both VTA cells and medial half of SN, pars compacta, whereas the septal HF (particularly CA1) receives its DA input from neurons located in the ventral half and in the upper and lower borders of the VTA.
向海马结构（HF）的一条主要的中脑边缘投射通路已被广泛描述，但尚未证实其多巴胺能成分的明确证据。为了评估投射到HF的腹侧被盖区（VTA-A10）和相邻黑质（SN-A9）中多巴胺能（DA）细胞的百分比，将逆行神经元示踪技术与酪氨酸羟化酶（TH）免疫细胞化学相结合。将荧光金（FG）注射到隔区和颞叶HF的几个区域（下托、CA1、CA3、齿状回）。含有逆行FG标记神经元的切片要么直接作为对照进行固定，要么与TH抗血清孵育并用罗丹明显色。对逆行标记和TH免疫反应染色细胞的定量评估表明，VTA和SN向HF的投射部分（15%-18%）是多巴胺能的。VTA中10%的DA神经元投射到对侧HF，而SN中没有。总之，颞叶HF（主要是下托和相邻的CA1）似乎接受来自VTA细胞和致密部SN内侧半部分的主要DA传入纤维，而隔区HF（特别是CA1）接受来自位于VTA腹侧半部分以及上、下边界神经元的DA输入。
