TY - JOUR
T1 - Transient retinal ganglion cells in the developing rat are characterized by specific morphological properties
AU - Ramoa, Ary S.
AU - Yamasaki, Edna N.
PY - 1996
Y1 - 1996
N2 - To determine whether dendritic development of mammalian retinal ganglion cells (RGCs) is affected by axonal target specificity, the morphology of three populations of maturing RGCs was examined. These included RGCs that exhibited either a transient, topographically incorrect, projection to the caudal superior colliculus (SC), or a transient projection to the caudal inferior colliculus (IC), in addition to a control group that exhibited a topographically correct projection to the caudal SC. Projection populations were identified by retrograde transport of rhodamine labeled latex microspheres injected into target nuclei. Labeled RGCs were then injected in vitro with Lucifer yellow to reveal the details of their dendritic morphology. Retinal ganglion cells making target errors, most of which ultimately die, were found to undergo a remarkable degree of morphological differentiation and could be categorized according to the adult type I, II, or III criteria. However, the relative proportions of these cell types were different among RGCs making transient connections versus those whose projections were preserved. Approximately half of the RGCs making topographically incorrect projections to the SC belonged to type III, in contrast to 6% that made a topographically correct projection. In addition, the population of cells sending axons to caudal IC did not include type III RGCs, but consisted of small type II neurons. The development of the basic dendritic form of each RGC type was only modestly influenced by its projection pattern; dendritic trees of cells making transient projections were essentially normal with only a slight, but statistically significant, reduction in dimensions. Moreover, dendritic remodeling was evident during maturation of neurons making either transient or normal projections. Together, these findings indicate that target specificity plays a relatively minor role on dendritic development of retinal ganglion cells.
AB - To determine whether dendritic development of mammalian retinal ganglion cells (RGCs) is affected by axonal target specificity, the morphology of three populations of maturing RGCs was examined. These included RGCs that exhibited either a transient, topographically incorrect, projection to the caudal superior colliculus (SC), or a transient projection to the caudal inferior colliculus (IC), in addition to a control group that exhibited a topographically correct projection to the caudal SC. Projection populations were identified by retrograde transport of rhodamine labeled latex microspheres injected into target nuclei. Labeled RGCs were then injected in vitro with Lucifer yellow to reveal the details of their dendritic morphology. Retinal ganglion cells making target errors, most of which ultimately die, were found to undergo a remarkable degree of morphological differentiation and could be categorized according to the adult type I, II, or III criteria. However, the relative proportions of these cell types were different among RGCs making transient connections versus those whose projections were preserved. Approximately half of the RGCs making topographically incorrect projections to the SC belonged to type III, in contrast to 6% that made a topographically correct projection. In addition, the population of cells sending axons to caudal IC did not include type III RGCs, but consisted of small type II neurons. The development of the basic dendritic form of each RGC type was only modestly influenced by its projection pattern; dendritic trees of cells making transient projections were essentially normal with only a slight, but statistically significant, reduction in dimensions. Moreover, dendritic remodeling was evident during maturation of neurons making either transient or normal projections. Together, these findings indicate that target specificity plays a relatively minor role on dendritic development of retinal ganglion cells.
KW - aberrant projections
KW - dendritic tree
KW - lucifer yellow
KW - superior colliculus
KW - visual system
UR - http://www.scopus.com/inward/record.url?scp=0029921659&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1096-9861(19960513)368:4<582::AID-CNE9>3.0.CO;2-0
DO - 10.1002/(SICI)1096-9861(19960513)368:4<582::AID-CNE9>3.0.CO;2-0
M3 - Article
C2 - 8744445
AN - SCOPUS:0029921659
SN - 0021-9967
VL - 368
SP - 582
EP - 596
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
IS - 4
ER -