Neuromuscular organization of the Ctenophore Pleurobrachia bachei

Comb jellies or ctenophores might evolve independently their neurons and synapses. However, the field lags due to the lack of microanatomical data about the neuro ‐muscular systems in this group of animals. Here, using immunohistochemistry and scanning electron microscopy, we describe the organization of both muscular and nervous systems in the sea gooseberry,Pleurobrachia bachei, from North Pacific. The diffuse neural system ofPleurobrachia consists of two subsystems: the subepithelial neural network and the mesogleal net with about 5,000 –7,000 neurons combined. In terms of cell type specification and diversity, ctenophores significantly exceed what we currently know about other prebilaterian groups, and even some basal bilaterians. The revealed unprecedented complexity of neuromuscular organization and receptors in this basal met azoan lineage supports complex ctenophore feeding, swimming, escape and prey capture behaviors. AbstractCtenophores are descendants of one of the earliest branching metazoan lineage with enigmatic nervous systems. The lack of convenient neurogenic molecules and neurotransmitters suggests an extensive parallel evolution and independent origins of neurons and synapses. However, the field lags due to the lack of microanatomical data about the neuro ‐muscular systems in this group of animals. Here, using immunohistochemistry and scanning electron microscopy, we describe the organization of both muscular and nervous systems in the sea gooseberry,...

Source: The Journal of Comparative Neurology - November 17, 2018 Category: Neurology Authors: Tigran P. Norekian, Leonid L. Moroz Tags: RESEARCH ARTICLE Source Type: research