Area X; Area X (specialized region of the avian striatum); Av; CM; DLM; DMP; Field L; Field L (avian primary auditory cortex); HVC; HVC (abbreviation used as a proper noun); LLv; LMAN; MLd; MMAN; Medial magnocellular nucleus of the anterior nidopallium; NCM; NIf; Ov; RA; UVA; VP; VTA; caudal mesopallium; caudomedial nidopallium; hypoglossal nucleus, tracheosyringeal nerve (12th cranial nerve nucleus); lateral magnocellular nucleus of the anterior nidopallium; nXIIts; nucleus avalanche; nucleus dorsolateralis anterior, pars medialis; nucleus dorsomedialis posterior thalami; nucleus interface of the nidopallium; nucleus mesencephalicus lateralis, pars dorsalis; nucleus ovoidalis; nucleus uvaeformis; robust nucleus of the arcopallium; ventral nucleus of the lateral lemniscus; ventral pallidum; ventral tegmental area