Premium
Connections of primary auditory cortex in the new world monkey, Saguinus
Author(s) -
Luethke L. E.,
Krubitzer L. A.,
Kaas J. H.
Publication year - 1989
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.902850406
Subject(s) - auditory cortex , inferior colliculus , medial geniculate body , biology , neuroscience , cortex (anatomy) , geniculate , anatomy , thalamus , dorsum , superior colliculus , tonotopy , nucleus
Connections of primary auditory cortex (A‐I) were investigated in the tamarin ( Saguinus fuscicollis ), a New World monkey. In each case, A‐I was defined by multiunit recordings, and best frequencies were determined for neurons at different recording sites. Microlesions were placed to mark recording sites for correlation with cortical architecture. Following mapping, separate injections of up to three different tracers (HRP‐WGA and fluorescent dyes) were placed into the representations of different frequencies within A‐I. The results support several conclusions: (1) high to low frequencies are represented in a dorsocaudal to ventrorostral sequence in A‐I, (2) intrinsic connections in A‐I are more pronounced along isofrequency contours, (3) the pattern of connections between A‐I and adjoining cortex suggests that this surrounding auditory cortex contains at least two tonotopically organized fields and possibly one or more additional auditory fields, (4) callosal connections of A‐I are largely between parts of A‐I matched for frequency representation, (5) thalamic connections of A‐I include topographic connections with the ventral division of the medial geniculate complex (MGv) and more diffuse connections with the medial (MGm) and dorsal (MGd) divisions of the medial geniculate complex and the suprageniculate nucleus (Sg), and (6) A‐I projects bilaterally to the dorsal cortex of the inferior colliculus.