Central pattern generator for vocalization: is there a vertebrate morphotype?

- Vocal communication is widespread among fishes, the largest group of vertebrates.
- Vocal fish and tetrapods share an evolutionarily conserved hindbrain CPG region.
- Vocal CPG of fish has compartments coding for distinct temporal properties.
- Vocal CPG of fish displays temporal precision on a millisecond timescale.
- Vocal CPG shares evolutionary developmental origins with pectoral movement system.

Animals that generate acoustic signals for social communication are faced with two essential tasks: generate a temporally precise signal and inform the auditory system about the occurrence of one's own sonic signal. Recent studies of sound producing fishes delineate a hindbrain network comprised of anatomically distinct compartments coding equally distinct neurophysiological properties that allow an organism to meet these behavioral demands. A set of neural characters comprising a vocal-sonic central pattern generator (CPG) morphotype is proposed for fishes and tetrapods that shares evolutionary developmental origins with pectoral appendage motor systems.