Wang J, Palkovits M, Usdin T B, Dobolyi A
Laboratory of Genetics, National Institute of Mental Health, Building 35, Room 1B215, 35 Convent Drive, Bethesda, MD 20892-3728, USA.
Neuroscience. 2006;138(4):1245-63. doi: 10.1016/j.neuroscience.2005.12.022. Epub 2006 Feb 3.
Neurons containing tuberoinfundibular peptide of 39 residues (TIP39) constitute a rostro-caudally elongated group of cells in the posterior thalamus. These neurons are located in the rostral part of the subparafascicular nucleus and in the subparafascicular area, caudally. Projections of the caudally located TIP39 neurons have been previously identified by their disappearance following lesions. We have now mapped the projections of the rat rostral subparafascicular neurons using injections of the anterograde tracer biotinylated dextran amine and the retrograde tracer cholera toxin B subunit, and confirmed the projections from more caudal areas previously inferred from lesion studies. Neurons from both the rostral subparafascicular nucleus and the subparafascicular area project to the medial prefrontal, insular, ecto- and perirhinal cortex, nucleus of the diagonal band, septum, central and basomedial amygdaloid nuclei, fundus striati, basal forebrain, midline and intralaminar thalamic nuclei, hypothalamus, subthalamus and the periaqueductal gray. The subparafascicular area projects more densely to the amygdala and the hypothalamus. In contrast, only the rostral part of the subparafascicular nucleus projects significantly to the superficial layers of prefrontal, insular, ectorhinal and somatosensory cortical areas. Double labeling showed that anterogradely labeled fibers from the rostral part of the subparafascicular nucleus contain TIP39 in many forebrain areas, but do not in hypothalamic areas. Injections of the retrograde tracer cholera toxin B subunit into the lateral septum and the fundus striati confirmed that they were indeed target regions of both the rostral subparafascicular nucleus and the subparafascicular area. In contrast, TIP39 neurons did not project to the anterior hypothalamic nucleus. Our data provide an anatomical basis for the potential involvement of rostral subparafascicular neurons in limbic and autonomic regulation, with TIP39 cells being major subparafascicular output neurons projecting to forebrain regions.
含有39个氨基酸残基的结节漏斗肽（TIP39）的神经元，在后丘脑形成了一个从嘴侧到尾侧延伸的细胞群。这些神经元位于束旁核嘴侧部分以及尾侧的束旁区域。先前通过损伤后其消失情况，已确定了尾侧TIP39神经元的投射。我们现在使用顺行示踪剂生物素化葡聚糖胺注射和逆行示踪剂霍乱毒素B亚基，绘制了大鼠束旁核嘴侧神经元的投射图，并证实了先前从损伤研究推断出的来自更尾侧区域的投射。来自束旁核嘴侧部分和束旁区域的神经元投射到内侧前额叶、岛叶、外侧和梨状周皮质、斜角带核、隔区、中央杏仁核和基底内侧杏仁核、纹状体底、基底前脑、中线和丘脑板内核、下丘脑、底丘脑以及导水管周围灰质。束旁区域向杏仁核和下丘脑的投射更为密集。相比之下，只有束旁核嘴侧部分向额叶、岛叶、嗅外皮质和体感皮质区域的浅层有显著投射。双重标记显示，来自束旁核嘴侧部分的顺行标记纤维在许多前脑区域含有TIP39，但在下丘脑区域则没有。将逆行示踪剂霍乱毒素B亚基注射到外侧隔区和纹状体底，证实它们确实是束旁核嘴侧部分和束旁区域的靶区。相比之下，TIP39神经元不投射到下丘脑前核。我们的数据为束旁核嘴侧神经元在边缘系统和自主神经调节中的潜在参与提供了解剖学基础，其中TIP39细胞是投射到前脑区域的主要束旁输出神经元。
