Targets of olivocochlear collaterals in cochlear nucleus of rat and guinea pig
| Autor: | Nathanael J. Yates, Donald Robertson, Wilhelmina Mulders, Ahmaed Baashar |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Cochlear Nucleus
Male 0301 basic medicine Inferior colliculus Auditory Pathways Guinea Pigs Population Olivary Nucleus Biology Cochlear nucleus 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Species Specificity Biocytin otorhinolaryngologic diseases Animals Rats Wistar education Cochlea education.field_of_study General Neuroscience Olivocochlear system Rats 030104 developmental biology nervous system chemistry Superior olivary complex Female sense organs Brainstem Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Journal of Comparative Neurology. |
| ISSN: | 1096-9861 0021-9967 |
| DOI: | 10.1002/cne.24681 |
| Popis: | Descending auditory pathways can modify afferent auditory input en route to cortex. One component of these pathways is the olivocochlear system which originates in brainstem and terminates in cochlea. Medial olivocochlear (MOC) neurons also project collaterals to cochlear nucleus and make synaptic contacts with dendrites of multipolar neurons. Two broadly distinct populations of multipolar cells exist: T-stellate and D-stellate neurons, thought to project to inferior colliculus and contralateral cochlear nucleus, respectively. It is unclear which of these neurons receive direct MOC collateral input due to conflicting results between in vivo and in vitro studies. This study used anatomical techniques to identify which multipolar cell population receives synaptic innervation from MOC collaterals. The retrograde tracer Fluorogold was injected into inferior colliculus or cochlear nucleus to label T-stellate and D-stellate neurons, respectively. Axonal branches of MOC neurons were labeled by biocytin injections at the floor of the fourth ventricle. Fluorogold injections resulted in labeled cochlear nucleus multipolar neurons. Biocytin abundantly labeled MOC collaterals which entered cochlear nucleus. Microscopic analysis revealed that MOC collaterals made some putative synaptic contacts with the retrogradely labeled neurons but many more putative contacts were observed on unidentified neural targets. This suggest that both T- and D-stellate neurons receive synaptic innervation from the MOC collaterals on their somata and proximal dendrites. The prevalence of these contacts cannot be stated with certainty because of technical limitations, but the possibility exists that the collaterals may also make contacts with neurons not projecting to inferior colliculus or the contralateral cochlear nucleus. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text