Structural and functional consequences of neonatal deafferentation in the superficial layers of the hamster's superior colliculus.
J Comp Neurol
; 315(4): 398-412, 1992 Jan 22.
Article
em En
| MEDLINE
| ID: mdl-1560114
ABSTRACT
Intracellular recording and horseradish peroxidase (HRP) injection techniques were used to evaluate the effects of neonatal enucleation upon the structural and functional properties of cells in the superficial retinorecipient laminae of the hamster's superior colliculus (SC). The physiological recordings confirmed previous results that normally visual superficial layer neurons develop somatosensory receptive fields in the enucleated animals. This study further showed that all of the physiological subclasses of somatosensory neurons normally encountered in the deep layers were present in the superficial laminae. With the exception of marginal cells, all of the morphological classes of neurons in the superficial SC laminae of sighted hamsters (narrowfield vertical cells, widefield vertical cells, stellate cells, horizontal cells, and giant stellate cells) were recovered from the blinded animals. Quantitative comparison of neurons within a given morphological class demonstrated only slight differences between cells from blind and sighted hamsters. However, there was a significant reduction in the percentage of neurons with dorsally directed dendrites in the neonatally enucleated animals. Additional experiments with the Golgi technique also demonstrated that neonatal enucleation altered the distribution of morphological cell types in the superficial SC laminae. These results suggest that enucleation in the hamster may result in relative reductions in specific cell types in the superficial SC laminae rather than dendritic changes in all of the cell classes present in these layers.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Colículos Superiores
/
Animais Recém-Nascidos
/
Neurônios Aferentes
Limite:
Animals
Idioma:
En
Revista:
J Comp Neurol
Ano de publicação:
1992
Tipo de documento:
Article