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| Author(s): |
Suzana Souza Souto
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2007-10-22 |
| Examining board members: |
Jackson Cioni Bittencourt;
Newton Sabino Canteras;
Renata Mota Mamede de Carvallo;
Alessandra Spada Durante;
Luciane Valéria Sita
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| Advisor: | Jackson Cioni Bittencourt |
| Abstract | |
After the discovery of the Urocortin-1, a neuropeptide found mainly in the Edinger-Westphal nucleus and in the lateral superior olive nucleus (LSO), the attention was caught about the lack of known projections of both nuclei. We intended to contribute to the knowledge of both ascending and descending projections of the LSO, using a neuronal anterograde tracer. In order to do that we use the Biotin-Dextran-Amine (BDA) injected in the LSO of rats, fifteen to twenty days later the rats were perfused, the brains and spinal cords were cut and the sections treated histochemically. We have found that there are four pathways leaving the LSO either ascending or descending in the central nervous system, as following: two ascending pathways, one ipsilateral to the injection, the most proeminent one and the contralateral pathway that is less dense; two descending pathways, one ipsilateral, much less evident, and the contralateral that is very moderate. Tracking the ipsilateral ascending pathway we have found the following structures well labeled with BDA: the LSO itself, nucleus of the trapezoid body, the lateral lemniscus and its nuclei, inferior and superior colliculus, the following thalamic nuclei: suprageniculate, medial geniculate, dorsal and medial parts and the primary somatosensory cortex. Tracking the contralateral descending pathway we have found the following structures: the LSO ipsi and contralateral; the nucleus of the trapezoid body; ventral cochlear nucleus, anterior part; dorsal cochlear nucleus; ventral cochlear nucleus, posterior part and, the eight nerve. The data we have found in this work suggests that the pathways from the LSO could reach as far as the somatosensory cortex in the prosencephalon and the cochlear complex nuclei in the brainstem, sending collaterals to the main nuclei related to the auditory pathway, probably contributing to the localization of the sound source, due to the anatomy of this specific sensory information. (AU) | |