Development and circuitry of the tunicate larval Motor Ganglion, a putative hindbrain/spinal cord homolog

• Published in: Journal of experimental zoology. Part B, Molecular and developmental evolution Vol. 342; no. 3; pp. 200 - 211
• Main Authors: Piekarz, Katarzyna M., Stolfi, Alberto
• Format: Journal Article
• Language: English
• Published: United States 01-05-2024
• Subjects: Animals; Central Pattern Generator; chordates; Ciona; connectome; Ganglia, Invertebrate - physiology; Larva - physiology; Motor Ganglion; Motor Neurons - physiology; Rhombencephalon - physiology; Spinal Cord - physiology; tunicates; Urochordata - physiology; Central Pattern Generator; chordates; Motor Ganglion; connectome; Ciona; tunicates
• ISSN: 1552-5007; 1552-5015; 1552-5015
• DOI: 10.1002/jez.b.23221

The Motor Ganglion (MG) is a small collection of neurons that control the swimming movements of the tunicate tadpole larva. Situated at the base of the tail, molecular and functional comparisons suggest that may be a homolog of the spinal cord and/or hindbrain (“rhombospinal” region) of vertebrates. Here we review the most current knowledge of the development, connectivity, functions, and unique identities of the neurons that comprise the MG, drawn mostly from studies in Ciona spp. The simple cell lineages, minimal cellular composition, and comprehensively mapped “connectome” of the Ciona MG all make this an excellent model for studying the development and physiology of motor control in aquatic larvae.
Diagrams summarizing the cell lineages, sensory inputs, and morphology of Motor Ganglion neurons in the Ciona larva.
Research Highlights
We review the latest research on the development, circuitry, and function of the Motor Ganglion of tunicate larvae, focused primarily on the most well‐studied species in the Ciona genus.