Local circuit interactions between the dorsal and ventral divisions of the cochlear nucleus are known to influence the evoked responses of the resident neurons to sound. In the present study, we examined the projections of neurons in the ventral cochlear nucleus to the dorsal cochlear nucleus by usi
The organization of the posterior ventral cochlear nucleus in the rat
β Scribed by J. M. Harrison; R. Irving
- Publisher
- John Wiley and Sons
- Year
- 1966
- Tongue
- English
- Weight
- 830 KB
- Volume
- 126
- Category
- Article
- ISSN
- 0021-9967
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β¦ Synopsis
The ventral cochlear nucleus was examined in 31 rats' brains prepared according to the protargol method of Bodian. The following regions were delimited on the basis of synaptic, cellular and axonal criteria.
Region 11, which occupies the central part of the nucleus, consists principally of cells (type g ) which receive modified bulbs of Held from the acoustic nerve and which send large axons to the trapezoid body, The cells were graded in size, the smallest (high frequency) being located dorsally and the largest (low frequency) bcing located ventrally. Associated with region I1 are the cells (type b ) of the acoustic nerve nucleus. These cells receive boutons from the acoustic nerve and send very large axons to the trapezoid body.
Region IV is located in the posterior part of the ventral cochlear nucleus and is composed of large multipolar cells (type k ) . The dendrites of these cells are spccifically organized with respect to the fibers of the acoustic nerve. Synaptic endings, from the descending branch of the acoustic nerve, consist of boutons on cell body and dendrites. The axons of these cells compose the stria of Hcld.
Region V is located in the posterior part of the ventral cochlear nucleus and appeared to have only intrinsic connections.
All regions received synaptic endings in addition to those which arose from the acoustic nerve.
π SIMILAR VOLUMES
The purpose of the experiment was to determine the connections of the three regions of the anterior vcntral cochlear nucleus in the rat. Lesions were placed in the regions of the nucleus in 11 rats. After 25 days each animal was sacrificed and its brain impregnated by the protargol method of Bodian.
The olivocochlear projection constitutes the last stage of the descending auditory system in the mammalian brain. Its neurons reside in the superior olivary complex (SOC) and project to the inner and outer hair cell receptors in the cochlea. Olivocochlear neurons were also reported to send axon coll