Zupanc Gunther K H, Corrêa Sônia A L
School of Engineering and Science, International University Bremen, Bremen, Germany.
Brain Behav Evol. 2005;65(1):14-25. doi: 10.1159/000081107. Epub 2004 Sep 30.
The central posterior nucleus of teleost fish is a cluster of neurons in the dorsal thalamus that plays an important role in controlling social behaviors. In the weakly electric gymnotiform fish, Apteronotus leptorhynchus, this nucleus forms a larger complex together with the prepacemaker nucleus, hence called central posterior/prepacemaker nucleus (CP/PPn). This complex is crucially involved in neural control of transient modulations of the electric organ discharge, which occur both spontaneously and in the context of social interactions. This control function is intimately linked to its pattern of connectivity with other brain regions. By employing an in vitro neuronal tract-tracing technique, we have, in the present study, identified a novel reciprocal connection between the CP/PPn and a cell group situated in the region between the ventral thalamus and the inferior lobe. Despite the previous interpretation by other authors of this cell group as the glomerular nucleus, the lack of a projection of this nucleus to the hypothalamus, as also demonstrated in the present investigation, makes such a homology unlikely. We, therefore, interpret this nucleus as a brain structure of unknown homology in other teleosts and suggest 'nucleus G' to identify it.
硬骨鱼的中央后核是背侧丘脑的一群神经元，在控制社会行为中起重要作用。在弱电裸背电鳗科鱼类线翎电鳗中，该核与起搏器前核共同形成一个更大的复合体，因此称为中央后核/起搏器前核（CP/PPn）。这个复合体至关重要地参与了对电器官放电瞬态调制的神经控制，这种调制既可以自发发生，也可以在社会互动的背景下发生。这种控制功能与其与其他脑区的连接模式密切相关。在本研究中，我们通过采用体外神经元示踪技术，确定了CP/PPn与位于腹侧丘脑和下叶之间区域的一个细胞群之间存在一种新的相互连接。尽管其他作者先前将这个细胞群解释为肾小球核，但本研究也证明该核缺乏向下丘脑的投射，这使得这种同源性不太可能。因此，我们将这个核解释为其他硬骨鱼中同源性未知的脑结构，并建议用“G核”来识别它。
