Spinal motoneurons of the goldfish, carassius auratus

The spinal cord of goldfish (Carassius auratus) was examined in normal and experimental animals by light and electron microscopy. Comparisons of Golgi material and electron micrographs have shown the large ventral horn motoneurons to have dendrites with few spines. The axon may arise from a ventral dendrite. Synapses on the motoneuron may be chemical or combined electrotinic and chemical or electrotonic between dendrites. Transection of the cord produced degeneration of small boutons, but large boutons remained intact. Small boutons were found on dorsal root axons and large boutons on interneurons in Golgi preparations. Boutons en passant may arise from myelinated fibers.