Epibranchial placodes-derived neurons innervate internal organs to transmit information such as heart rate, blood pressure, and visceral distension from the periphery to the central nervous system (Baker and Bronner-Fraser, 2001). From rostral to caudal the epibranchial placodes comprise the geniculate, petrosal, and nodose placodes, each associated in sequence with the first, second and third branchial clefts. Each placode contributes sensory neurons to cranial nerves VII (facial nerve), IX (glossopharyngeal nerve), and X (vagal nerve), respectively

Focal thickenings of the embryonic ectoderm that form immediately dorsal and caudal of the clefts between the pharyngeal arches and that produce the neuroblasts that migrate and condense to form the distal cranial ganglia. [Graham_A, The_development_and_evolution_of_the_pharyngeal_arches._J_Anat_(2001)_199:_133-141][VHOG]

in XAO this develops_from dorsolateral placode, but in NBK53175, this is a separate group

uberon

ventrolateral placode

These (the epibranchial placodes) are focal thickenings of the embryonic ectoderm that form immediately dorsal and caudal of the clefts between the pharyngeal arches in all vertebrates, and they produce the neuroblasts which migrate and condense to form the distal cranial ganglia: the geniculate, petrosal and nodose ganglia. (...) The one substantial difference between the vertebrate pharyngeal arches and those of the protochordates is the presence of the epibranchial placodes but the evolution of these structures was undoubtedly driven by the endoderm.[well established][VHOG]

UBERON:0003078

• dorsolateral placode

• epibranchial ganglion