On the agonistic display of the Siamese fighting fish: II. The distribution, number and morphology of opercular display motoneurons
Brain, Behavior and Evolution, 45 (6):
314--326 (June 1995)Abstract
Examined the distribution, number, and morphology of opercular dilator motoneurons in the trigeminal motor nucleus of Siamese fighting fish to define the neural substrate for agonistic display. The trigeminal motor nucleus consists of 3 subnuclei: rostral, caudomedial (CM), and caudolateral (CL). Neuron numbers among these 3 subnuclei are relatively constant between males and females. Innervation of the opercular dilator muscle originates predominantly from the CL subnucleus. Labeling of the CL subnucleus is usually intense, whereas CM neurons are weakly labeled. Data suggest that neurons in the CM subnucleus provide either sparse and widespread innervation, or innervate only a small, circumscribed area of the opercular dilator muscle complex, whereas CL neurons probably provide extensive and dense innervations. The dendritic morphology of trigeminal motoneurons is independent of their targets and of the subnuclei in which they are located.