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Organization of the zebra finch song control system: Functional organization of outputs from nucleus robustus archistriatalis
Author(s) -
Vicario David S.
Publication year - 1991
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903090405
Subject(s) - hypoglossal nucleus , midbrain , biology , nucleus , anatomy , neuroscience , functional organization , central nervous system
The organization of projections from nucleus robustus archistriatalis (RA) was mapped by a combination of anatomical tracer techniques. After injections of retrograde tracers in the syringeal part of the hypoglossal motor nucleus (nXIIts), labelled cells were seen in ipsilateral RA, in agreement with previous work. However, a shallow band in the dorsal and dorsocaudal part of RA did not contain labelled cells. Cells in this “cap” area were labelled following tracer injections in the dorsomedial nucleus of midbrain ICo (DM), the other known target of RA projections. The topography of outputs to nXIIts was further examined by making small injections of retrograde tracer into physiologically identified control zones for individual syringeal muscles in nXIIts. The distribution of labelled cells in RA revealed bands of cells that cross RA in approximately horizontal layers and project to different parts of nXIIts. This topography was confirmed with the anterograde tracer PHA‐L. Thus RA contains two functional subdivisions, one related to midbrain centers for vocalization and the other directly controlling syringeal motorneurons. The latter area can be further divided into zones that preferentially engage particular syringeal muscles.