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Connections of the anterior commissure in the pigeon ( Columba livia )
Author(s) -
Zeier Hans J.,
Karten Harvey J.
Publication year - 1973
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.901500207
Subject(s) - anterior commissure , anatomy , posterior commissure , commissure , biology , medial forebrain bundle , cerebrum , neuroscience , nucleus , central nervous system , striatum , dopamine
Abstract1 The projections of the anterior commissure of the pigeon ( Columba livia ) were studied experimentally using the Fink‐Heimer methods. The anterior commissure was sectioned immediately to one side of the midline, and animals sacrificed from 2 to 17 days post‐operatively. 2 The anterior commissure divides into two major fascicles on crossing the midline: a relatively diffuse anterior medial branch (or pars bulbaris), and a more compact laterally directed posterior branch (the pars temporalis). 3 The pars bulbaris passes rostrally medial to the lateral forebrain bundle (FPL), terminating, in course, in an area ventrolateral to the nucleus accumbens, the lobus parolfactorius, the dorsal portions of the olfactory tubercle, and in restricted regions on the medial edge of PA, neostriatum, and hyperstriatum ventrale. At the rostral end of the telencephalon the pars bulbaris converges with the pars temporalis in the region of the hyperstriatum intercalatus superior (HIS). 4 The pars temporalis of the anterior commissure terminates in the anterior one‐third of the contralateral archistriatum. Numerous fibers leave the archistriatum and follow two separate trajectories: a dorsolaterally projecting pathway terminating in the temporo‐parieto‐occipital corticoid area (TPO of Edinger 1903), which continues anterolaterally to HIS; a ventrolateral rostrally directed path which parallels the tractus fronto‐archistriaticus, terminating in the deep layers of the piriform cortex. At rostral levels this latter bundle turns dorsally to merge with the anteromedial and dorsolateral trajectories in the region of HIS. 5 The pattern of termination in the archistriatum indicates the presence of several discrete subnuclei within the anterior archistriatum. A tentative terminology is suggested for the major subdivisions of the anterior archistriatum.There were no commissural projections to those specific sensory neuronal fields in direct receipt of thalamic efferents such as the ectostriatum, Field L or the visual wulst.