open access

https://hdl.handle.net/2115/43965

A Golgi-Electron Microscopic Study of Anterior Preoptic Neurons in the Bullfrog and the Toad

英語

1984

Zoological Society of Japan

Zoological Science

1

89-99

The structures of certain neurons in the anterior part of the preoptic nucleus (APON), which is a presumed center for anuran mating behavior, were studied using Golgi-electron microscopic and scanning electron microscopic techniques. The examined locus contains cerebrospinal fluid (CSF)-contacting neurons and blood capillary (BC)-contacting neurons. Gold-toned CSF-contacting neurons were examined by scanning electron microscopy after removal of surrounding tissues with hydrochloric acid and collagenase. The somata of these neurons bear debris of nerve terminals on their surfaces, while their processes protrude into the preoptic recess. It is probable that these neurons receive neuronal inputs on their somata and detect ventricular hormonal inputs on their intraventricular end bulbs. Further, when unstained semithin sections of gold-toned neurons were examined by scanning transmission electron microscopy, it was found that the BC-contacting neurons sent their dendrites laterad toward the white matter. There, many axon terminals form synapses on the dendritic spines of these neurons. The BC-contacting neurons probably detect changes in titers of blood-born hormones, and receive neuronal inputs through dendritic synapses. Thus, the present study shows that a portion of the APON neurons have the proper anatomical features for integrating both neural and hormonal signals concerned with the initiation of sex behavior.

学術雑誌論文

Version of Record

0289-0003