Yañez J, Anadón R
Department of Cell and Molecular Biology, University of La Coruña, Spain.
J Comp Neurol. 1996 Sep 2;372(4):529-43. doi: 10.1002/(SICI)1096-9861(19960902)372:4<529::AID-CNE3>3.0.CO;2-6.
The habenula is a conserved structure in the brain of vertebrates. With the aim of further understanding of the evolution of the habenular system in vertebrates, we studied the afferent and efferent connections of the habenula of the rainbow trout. Experiments included application of the carbocyanine dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) into the habenula, telencephalon, pineal organ, posterior tubercle, and interpeduncular nucleus (IPN). The results obtained reveal a consistent pattern of habenular connections. Most afferents originate from three nuclei, one extending from the preoptic region to the rostral thalamus (the entopeduncular nucleus), the second located in the region of the hypothalamus-posterior tubercle and consisting of large bipolar cells (tuberculohabenular nucleus), and the third in the preoptic region (preoptic nucleus). A few large neurons of the locus coeruleus appeared to be labeled in some cases. The trout habenula also receives pineal and parapineal projections. Small labeled glial cells were observed in the thalamus around the fasciculus retroflexus and, sometimes, around the IPN. The most conspicuous efferents coursed in the fasciculus retroflexus to the IPN, the isthmal raphe, and the central gray. The existence of olfactohabenular or habenulotelencephalic projections is discussed.
缰核是脊椎动物脑中一个保守的结构。为了进一步了解脊椎动物缰核系统的进化，我们研究了虹鳟鱼缰核的传入和传出连接。实验包括将碳氰染料1,1'-二辛基-3,3,3',3'-四甲基吲哚碳菁高氯酸盐（DiI）应用于缰核、端脑、松果体、后结节和脚间核（IPN）。所获得的结果揭示了缰核连接的一致模式。大多数传入纤维起源于三个核团，一个从视前区延伸至丘脑前部（内侧缰核），第二个位于下丘脑 - 后结节区域，由大的双极细胞组成（结节缰核），第三个在视前区（视前核）。在某些情况下，蓝斑的一些大神经元似乎被标记。虹鳟鱼的缰核也接受松果体和旁松果体的投射。在丘脑的返曲束周围以及有时在脚间核周围观察到小的标记胶质细胞。最明显的传出纤维经返曲束通向脚间核、峡中缝核和中央灰质。文中讨论了嗅缰或缰核 - 端脑投射的存在情况。
