Growth and restriction of the ipsilateral retinocollicular projection in the opossum

Mendez-Otero, Rosália; Cavalcante, Leny A.; Rocha‐Miranda, Carlos Eduardo; Bernardes, R. F.; Barradas, Penha C.

doi:10.1016/0165-3806(85)90264-0

Cited by 30 publications

(11 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The developmental sequences observed in the present study show many qualitative similarities to those in other marsupials (Cavalcante and Rocha-Miranda, 1979;Sanderson et al, 1982;Wye-Dvorak, 1984;Menendez-Otero et al, 1985;Harman and Beazley, 1986) and in eutherians (see, e.g., Lund and Bunt, 1975;Rakic, 1977;Frost et al, 1979;Williams and Chalupa, 1982;Bunt et al, 1983;Cavalcante and Barradas, 1995). The contralateral projection slightly precedes and is stronger than the ipsilateral; innervation of the SC occurs before that of the dLGN, and there is a phase of exuberance with subsequent retraction to the adult pattern.…”

Section: Timing Of Developmental Eventssupporting

confidence: 60%

Development of primary visual projections occurs entirely postnatally in the fat-tailed dunnart, a marsupial mouse,Sminthopsis crassicaudata

Dunlop

Tee

Lund³

et al. 1997

J. Comp. Neurol.

View full text Add to dashboard Cite

We have examined the development of retinal projections in a diminutive polyprotodont marsupial, the fat-tailed dunnart, Sminthopsis crassicaudata. Here, we document the most immature mammalian visual system at birth described to date. At postnatal day (P) 0, the retinal ganglion cell layer has yet to form, and axons have not entered the optic stalk. By P4, the retinal ganglion cell layer could be distinguished at the posterior pole, and the front of growing axons extended one-third the length of the optic stalk, a distance of approximately 150 microm; a few pioneer growth cones had grown beyond the main axon group but had still to reach the midline. Axons had decussated at the optic chiasm by P10 to penetrate the base of the contralateral optic tract and, by P15, had reached the dorsal lateral geniculate nucleus (dLGN), superior colliculus (SC), and accessory optic system (AOS); ipsilaterally projecting axons matured slightly later. From P20, axons had reached the caudal SC both contralaterally and ipsilaterally and terminated throughout the depth of the retinorecipient layers. After P30, the projections gradually refined. Within the rostral dLGN, segregation into four contralateral and four ipsilateral bands occurred by P50, approximately 5 days after eye opening. The projection to the ipsilateral SC underwent refinement by P50, becoming restricted to its rostral pole, and presented as discrete patches within the stratum opticum. At birth, the dunnart visual system is comparable to early to midembryonic stages [embryonic day (E) 12, E14, E19, E24, and E30, respectively] in the mouse, rat, ferret, cat, and monkey. The extreme immaturity of the neonatal dunnart together with the observation that the entire development of the primary optic pathway occurs postnatally over a protracted period make this marsupial especially valuable for investigating factors that control pathway formation in the early developing mammalian primary visual system.

show abstract

Section: Timing Of Developmental Eventssupporting

confidence: 60%

Development of primary visual projections occurs entirely postnatally in the fat-tailed dunnart, a marsupial mouse,Sminthopsis crassicaudata

Dunlop

Tee

Lund³

et al. 1997

J. Comp. Neurol.

View full text Add to dashboard Cite

show abstract

“…Neither in P22 nor in P30 was it possible to identify R terminals in spite of evidence from HRP tracer studies indicating that the selective arborization of retinal fibers in their definitive locations appears to start by P26 [Mendez-Otero et al, 1985]. Furthermore, RSD (C-like), F or P terminals have not been identified in either P22 or P30.…”

Section: P22 and P30mentioning

confidence: 85%

“…Three pieces of tissue encompassing all of the collicular depth were cut from 150 µm Vibratome sections with the portion of the superficial layers corresponding approximately to the rostral pole (RP -rostral third of SC), the direct binocular region (DBR -middle third) and caudal region (CR -caudal third) [RochaMiranda et al, 1978;Mendez-Otero et al, 1985].…”

Section: Tissue Preparationmentioning

confidence: 99%

“…al., 1985Harman and Beazley, 1986;Barradas et al, 1989Barradas et al, , 1995Harman, 1991;Mark et al, 1993;Dunlop, 1997]. The early birth and slow rate of postnatal development have favored the disclosure of features either unknown or uncommon among eutherians, such as the occurrence of tangential gradients of neurogenesis within the SC superficial layers [opossum: Cavalcante et al, 1984 vs. monkey: Cooper andRakic, 1981] and of selective arborization of retinal fibers in their definite locations [opossum: Mendez-Otero et al, 1985and wallaby: Mark et al, 1993vs. Simon and O'Leary, 1992.…”

Section: Introductionmentioning

confidence: 99%

“…The refined organization of the marsupial retinocollicular system has led to several studies of the normal and abnormal development of SC [Cavalcante and Rocha-Miranda, 1978a, b;Lent and Mendez-Otero, 1980;Sanderson et al, 1982;Cavalcante et al, 1984Cavalcante et al, , 1991Mendez-Otero et. al., 1985Harman and Beazley, 1986;Barradas et al, 1989Barradas et al, , 1995Harman, 1991;Mark et al, 1993;Dunlop, 1997].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synaptogenesis in Retino-Receptive Layers of the Superior Colliculus of the Opossum Didelphis marsupialis

Correa-Gillieron

Cavalcante

1999

Brain Behav Evol

Self Cite

View full text Add to dashboard Cite

The maturation of the neuropil and synapse formation were examined in the retino-receptive layers of the superior colliculus (SCr-r) in the opossum from a period prior to the onset of arborization of retinocollicular fibers (postnatal day 22 – P22), at 44% of the coecal period (CP), to the end of the fast phase of optic fiber myelination and weaning time (P81 – 118% CP). Development of the SCr-r neuropil follows a protracted time course and can be divided into three broad stages, which are characterized by (I) Large extracellular spaces, numerous growth cones that participate rarely in synaptic junctions, vesicles-poor immature synapses (P22–P30), (II) Synapses of varied morphology with abundant synaptic vesicles, and small terminals with dark mitochondria and round synaptic vesicles (RSD terminals) synapsing mostly onto dendritic shafts, flat-vesicles (F) terminals (P40–P56), (III) Sequential appearance of retinal (R) and pleomorphic-vesicles (P) terminals and of RSD terminals synapsing onto spine or spine-like processes, appearance of glomerulus-like synaptic arrays (synaptic islets) (P61–P81). The advancement of synaptogenesis in SCr-r from stage I to II and from stage II to III correlates closely with the differentiation of astrocytes and oligodendrocytes, respectively.

show abstract

Development of visual projections follows an avian/mammalian‐like sequence in the lizard Ctenophorus ornatus

Dunlop¹,

Tee

Rodger

et al. 2002

J of Comparative Neurology

View full text Add to dashboard Cite

Development of primary visual projections was examined in a lizard Ctenophorus ornatus by anterograde and retrograde tracing with DiI and by GAP-43 immunohistochemistry. Visual pathway development was essentially similar to that in birds and mammals and thus differed from patterns in fish or amphibians. A number of features characterised the development as mammalian-like. Three phases occurred in rapid succession after laying: outgrowth (2-3 weeks, early), exuberance (4-5 weeks, intermediate), and retraction to the adult pattern (6-8 weeks, late) at about the time of hatching and eye opening. Furthermore, ipsilateral projections developed with only a slight lag relative to the contralateral ones. The dorsally located fovea could be identified from early stages. Optic axons formed transient exuberant projections to the ipsilateral optic tectum, to the opposite optic nerve, and to nonvisual regions. The pattern resembled that formed in the long term by regenerating optic axons in C. ornatus (Dunlop et al. [2000b] J. Comp. Neurol. 416:188-200), suggesting that axons recognise molecular signals associated with the initial exuberant innervation but not those associated with subsequent refinement.

show abstract

Growth and restriction of the ipsilateral retinocollicular projection in the opossum

Cited by 30 publications

References 31 publications

Development of primary visual projections occurs entirely postnatally in the fat-tailed dunnart, a marsupial mouse,Sminthopsis crassicaudata

Development of primary visual projections occurs entirely postnatally in the fat-tailed dunnart, a marsupial mouse,Sminthopsis crassicaudata

Synaptogenesis in Retino-Receptive Layers of the Superior Colliculus of the Opossum Didelphis marsupialis

Development of visual projections follows an avian/mammalian‐like sequence in the lizard Ctenophorus ornatus

Contact Info

Product

Resources

About