Combining visual information from the two eyes: the relationship between isthmotectal cells that project to ipsilateral and to contralateral optic tectum using fluorescent retrograde labels in the frog, Rana pipiens.
J Comp Neurol
; 502(1): 38-54, 2007 May 01.
Article
en En
| MEDLINE
| ID: mdl-17335048
ABSTRACT
The frog nucleus isthmi (homolog of the mammalian parabigeminal nucleus) is a visually responsive tegmental structure that is reciprocally connected with the ipsilateral optic tectum; cells in nucleus isthmi also project to the contralateral optic tectum. We investigated the location of the isthmotectal cells that project ipsilaterally and contralaterally using three retrograde fluorescent label solutions Alexa Fluor 488 10,000 mw dextran conjugate; Rhodamine B isothiocyanate; and Nuclear Yellow. Dye solutions were pressure-injected into separate sites in the superficial optic tectum. Following a 6-day survival, brains were fixed, sectioned, and then photographed. Injection of the different labels at separate, discrete locations in the optic tectum result in retrograde filling of singly labeled clusters of cells in both the ipsilateral and contralateral nucleus isthmi. Generally, ipsilaterally projecting cells are dorsal to the contralaterally projecting cells, but there is a slight overlap between the two sets of cells. Nonetheless, when different retrograde labels are injected into opposite tecta, there is no indication that individual cells project to both tecta. The set of cells that project to the ipsilateral tectum and the set of cells that project to the contralateral tectum form a visuotopic map in a roughly vertical, transverse slab. Our results suggest that nucleus isthmi can be separated into two regions with cells in the dorsolateral portion projecting primarily to the ipsilateral optic tectum and cells in the ventrolateral nucleus isthmi projecting primarily to the contralateral optic tectum.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Rana pipiens
/
Vías Visuales
/
Visión Binocular
/
Colículos Superiores
/
Lateralidad Funcional
Límite:
Animals
Idioma:
En
Revista:
J Comp Neurol
Año:
2007
Tipo del documento:
Article
País de afiliación:
Estados Unidos