A specialized reciprocal connectivity suggests a link between the mechanisms by which the superior colliculus and parabigeminal nucleus produce defensive behaviors in rodents
Author
dc.contributor.author
Deichler, Alfonso
Author
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Carrasco, Denisse
Author
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López Jury, Luciana
Author
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Vega Zúñiga, Tomás
Author
dc.contributor.author
Márquez, Natalia
Author
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Mpodozis Marín, Jorge
Author
dc.contributor.author
Marín, Gonzalo J.
Admission date
dc.date.accessioned
2021-01-13T21:27:01Z
Available date
dc.date.available
2021-01-13T21:27:01Z
Publication date
dc.date.issued
2020
Cita de ítem
dc.identifier.citation
Scientific Reports (2020) 10:16220
es_ES
Identifier
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10.1038/s41598-020-72848-0
Identifier
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https://repositorio.uchile.cl/handle/2250/178237
Abstract
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The parabigeminal nucleus (PBG) is the mammalian homologue to the isthmic complex of other vertebrates. Optogenetic stimulation of the PBG induces freezing and escape in mice, a result thought to be caused by a PBG projection to the central nucleus of the amygdala. However, the isthmic complex, including the PBG, has been classically considered satellite nuclei of the Superior Colliculus (SC), which upon stimulation of its medial part also triggers fear and avoidance reactions. As the PBG-SC connectivity is not well characterized, we investigated whether the topology of the PBG projection to the SC could be related to the behavioral consequences of PBG stimulation. To that end, we performed immunohistochemistry, in situ hybridization and neural tracer injections in the SC and PBG in a diurnal rodent, the Octodon degus. We found that all PBG neurons expressed both glutamatergic and cholinergic markers and were distributed in clearly defined anterior (aPBG) and posterior (pPBG) subdivisions. The pPBG is connected reciprocally and topographically to the ipsilateral SC, whereas the aPBG receives afferent axons from the ipsilateral SC and projected exclusively to the contralateral SC. This contralateral projection forms a dense field of terminals that is restricted to the medial SC, in correspondence with the SC representation of the aerial binocular field which, we also found, in O. degus prompted escape reactions upon looming stimulation. Therefore, this specialized topography allows binocular interactions in the SC region controlling responses to aerial predators, suggesting a link between the mechanisms by which the SC and PBG produce defensive behaviors.
es_ES
Patrocinador
dc.description.sponsorship
Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)
Conicyt Fondecyt
1151432
1170027
Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)
21161599
A specialized reciprocal connectivity suggests a link between the mechanisms by which the superior colliculus and parabigeminal nucleus produce defensive behaviors in rodents