Johnston S A, Maler L, Tinner B
Department of Anatomy, Faculty of Medicine, University of Ottawa, Ontario, Canada.
J Chem Neuroanat. 1990 Nov-Dec;3(6):429-65.
The immunohistochemical distribution of serotonin (5-HT) cells, fiber tracts and terminal fields was mapped in the brain of the gymnotiform electric fish. Two major types of 5-HT cells were found: the small paraventricular organ (PVO) cells of the diencephalon, and the large raphe cells of the brain stem. Six diencephalic nuclei were identified: the nucleus preopticus periventricularis, anterior division, nucleus posterioris periventricularis, nucleus recessus lateralis medial subdivisions 1, 2 and 3, and nucleus recessus posterioris. In the brainstem, raphe centralis, between the arms of the medial longitudinal fasciculus (MLF), the raphe medialis, lateral to MLF, and the diffuse raphe posterioris, were described. Five 5-HT fiber tracts were identified. The tract rising from PVOs projected rostrally through the medial forebrain bundle (MFB). The central tegmental bundle arising from the raphe centralis-medialis complex projected rostrally and also joined the MFB. The lateral tegmental tract, the ventrolateral and the subtrigeminal tracts arose from brain stem raphe groups and innervated the brainstem nuclei. The densest 5-HT innervation occurred in the hypothalamus in the neuropil of the PVOs and in the brainstem in the interpeduncular nucleus, cranial nerve nuclei V motor, V tractus spinalis, VII, X sensory and lateral inferior olive. Electrosensory nuclei including the electrosensory lateral line lobe, the nucleus praeminentialis, dorsal torus semicircularis, optic tectum, nucleus electrosensorius and prepacemaker nucleus received light to medium 5-HT innervation. Serotonergic terminal fields appeared to be conserved across phyla with additional innervation evident in specialized sensory regions such as the electrosensory nuclei of gymnotiform and mormyriform fish.
绘制了裸背电鳗目电鱼大脑中血清素（5-羟色胺，5-HT）细胞、纤维束和终末场的免疫组织化学分布图。发现了两种主要类型的5-HT细胞：间脑的小室旁器官（PVO）细胞和脑干的大缝际核细胞。确定了六个间脑核：室周视前核、前部分、室周后核、外侧隐窝核内侧亚区1、2和3，以及后隐窝核。在脑干中，描述了位于内侧纵束（MLF）臂之间的中央缝际核、位于MLF外侧的内侧缝际核和弥散的后缝际核。确定了五条5-HT纤维束。从PVO发出的纤维束向前通过内侧前脑束（MFB）投射。由中央缝际核-内侧缝际核复合体发出的中央被盖束向前投射并也加入MFB。外侧被盖束、腹外侧束和三叉神经下束起源于脑干缝际核群并支配脑干核。最密集的5-HT神经支配出现在下丘脑的PVO神经毡以及脑干的脚间核、动眼神经核V、脊髓束V、面神经核VII、感觉神经核X和下橄榄外侧核。包括电感觉侧线叶、前顶核、背侧半规管、视顶盖、电感觉核和起搏器前核在内的电感觉核接受轻度至中度的5-HT神经支配。血清素能终末场似乎在各门类中是保守的，在特殊感觉区域如裸背电鳗目和长颌鱼目鱼类的电感觉核中明显有额外的神经支配。
