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Authordc.contributor.authorMpodozis Marín, Jorge es_CL
Authordc.contributor.authorSalas, Carlos es_CL
Authordc.contributor.authorSentis, Elisa es_CL
Authordc.contributor.authorRojas, Ximena es_CL
Authordc.contributor.authorLetelier Parga, Juan es_CL
Authordc.contributor.authorMarín Game, Gonzalo es_CL
Admission datedc.date.accessioned2008-05-14T14:01:52Z
Available datedc.date.available2008-05-14T14:01:52Z
Publication datedc.date.issued2007es_CL
Cita de ítemdc.identifier.citationJOURNAL OF NEUROSCIENCE Vol. 27 01/07/2025 2007 30 8112-8121es_CL
Identifierdc.identifier.urihttps://repositorio.uchile.cl/handle/2250/118704
General notedc.descriptionPublicación ISIes_CL
Abstractdc.description.abstractWe describe the operation of a midbrain neural circuit in pigeons that may participate in selecting and attending to one visual stimulus from the myriad displayed in their visual environment. This mechanism is based on a topographically organized cholinergic signal reentering the optic tectum (TeO). We have shown previously that, whenever a visual stimulus activates neurons in a given tectal location, this location receives a strong bursting feedback from cholinergic neurons of the nucleus isthmi pars parvocellularis (Ipc), situated underneath the tectum. Here we show that, if a second visual stimulus is presented, even far from the first, the feedback signal to the first tectal location is diminished or suppressed, and feedback to the second tectal location is initiated. We found that this long-range suppressive interaction is mostly mediated by the nucleus isthmi pars magnocellularis, which sends a wide-field GABAergic projection to Ipc and TeO. In addition, two sets of findings indicate that the feedback from the Ipc modulates the ascending output from the TeO. First, visually evoked extracellular responses recorded in the dorsal anterior subdivision of the thalamic nucleus rotundus (RtDa), receiving the ascending tectal output, are closely synchronized to this feedback signal. Second, local inactivation of the Ipc prevents visual responses in RtDa to visual targets moving in the corresponding region of visual space. These results suggest that the ascending transmission of visual activity through the tectofugal pathway is gated by this cholinergic re-entrant signal, whose location within the tectal visual map is dynamically defined by competitive interactions.es_CL
Lenguagedc.language.isoenes_CL
Keywordsdc.subjectspatial attentiones_CL
Area Temáticadc.subject.otherNeuroscienceses_CL
Títulodc.titleA cholinergic gating mechanism controlled by competitive interactions in the optic tectum of the pigeones_CL
Document typedc.typeArtículo de revista


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