Neuronal segmentation in cephalopod arms.

The prehensile arms of the cephalopod are among these animals' most remarkable features, but little is known about the neural circuitry governing arm and sucker movements. Here, we investigated the cellular and molecular organization of the arm nervous system, focusing on the massive axial nerve cords (ANCs) in the octopus arms which collectively harbor four times as many neurons as the central brain. We found that the ANC is segmented.

Neuronal segmentation in cephalopod arms.

The prehensile arms of the cephalopod are among these animals most remarkable features, but the neural circuitry governing arm and sucker movements remains largely unknown. We studied the neuronal organization of the adult axial nerve cord (ANC) of with molecular and cellular methods. The ANCs, which lie in the center of every arm, are the largest neuronal structures in the octopus, containing four times as many neurons as found in the central brain.

Hox Function Is Required for the Development and Maintenance of the Drosophila Feeding Motor Unit.

Feeding is an evolutionarily conserved and integral behavior that depends on the rhythmic activity of feeding muscles stimulated by specific motoneurons. However, critical molecular determinants underlying the development of the neuromuscular feeding unit are largely unknown. Here, we identify the Hox transcription factor Deformed (Dfd) as essential for feeding unit formation, from initial specification to the establishment of active synapses, by controlling stage-specific sets of target genes.