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The Development of Retinal Ganglion Cell Decussation Patterns in Postnatal Pigmented and Albino Ferrets
Author(s) -
Thompson I. D.,
Morgan J. E.
Publication year - 1993
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.1993.tb00502.x
Subject(s) - decussation , retinal ganglion cell , intrinsically photosensitive retinal ganglion cells , ganglion , retinal , neuroscience , giant retinal ganglion cells , biology , anatomy , retina , zoology , biochemistry
The decussation patterns of retinal ganglion cells in postnatal pigmented and albino ferrets were examined by using retrograde axonal tracers. Following unilateral injections into the optic pathway of newborn pigmented ferrets, ∼ 13 000 cells were labelled in the ipsilateral retina. The majority (11 500) of these were located in temporal retina. Postnatally, the numbers of cells projecting ipsilaterally from temporal retina fell by 49%. High rates of loss were observed in both the smaller uncrossed projection from nasal retina (92%) and also in the crossed projection from temporal retina (84%). After injections on the day of birth, a decussation line was not obvious in the crossed projection: ≥ 14 000 labelled cells were found in temporal retina. Double tracer studies showed that very few of these cells had axons which projected bilaterally. The numbers of ipsilaterally projecting cells labelled in neonatal albino ferrets was dramatically reduced. Only ∼ 2500 were labelled in temporal retina following injections at birth. As in pigmented ferrets, about half of these cells subsequently died. The reduced uncrossed projection in albino neonates was asociated with an increase in the crossed projection from temporal retina, in which ∼ 21 000 cells were labelled following injections at birth. These results suggest that differential postnatal ganglion cell death establishes the adult decussation pattern in the contralateral retinal projection but merely refines the pattern already established in the uncrossed projection. Postnatal ganglion cell death plays no significant role in generating the abnormal projections found in albino ferrets.