Aminergic nuclei in the hypothalamus of the roach Leuciscus rutilus.

In the hypothalamus of the roach (Leuciscus rutilus) green and yellow fluorescent cells were found in the nucleus recessus lateralis (NRL) and the nucleus recessus posterioris (NRP) and green fluorescent cells in the nucleus recessus preopticus (NRPO). The green fluorescence indicates the presence of noradrenaline or dopamine and the yellow one the presence of 5-hydroxytryptamine. The cells of the NRL and NRP contained electron dense granules averaging 70 nm in diameter. The NRL is divided into two parts. These and the NRP are connected by large fluorescent tracts. The NRL and NRP send axons towards the nucleus lateralis tuberis (NLT) and the NRPO sends axons towards the nucleus preopticus (NPO). It could not be established whether the aminergic nuclei described are the origin of the fluorescent fibers in the hypophysis of the roach.