Summary
Ultrastructural study of the molecular layer of the neocortex of a 7 week-old human embryo confirms recent observations on various laboratory animals that call for revision of some classical concepts of corticogenesis.
-
1.
At 7 weeks, the subpial, marginal or molecular layer is the first layer to differentiate from the ventricular layer and represents almost half the thickness of the telencephalic vesicle.
-
2.
The first cells that have already migrated from the ventricular zone, even before any cortical plate is visible, are to be found in this marginal layer. These large cells are well differentiated and most probably represent the so called Cajal Retzius cells.
-
3.
The earliest synapses ever seen in human embryol are found in the marginal or plexiform layer; this indicates the presence of a precocious set-up for an elaborate neuronal circuitry at this level.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Angevine JB, Sidman RL (1961) Autoradiographic study of cell migration during histogenesis of cerebral cortex of the mouse. Nature (London) 192:766–768
Angevine JB (1965) Time of neuron origin in the hippocampal region. An autoradiographic study in the mouse. Exp Neurol suppl 2:1–70
Aström KE (1967) On the early development of the neocortex in fetal sheep. In: CC Bernhard and JP Schade (Eds) Developmental Neurology. Progress in Brain Res 26:1–59
Bartelmez GW, Dekaban AS (1962) The early development of the human brain. Contr Embryol Carneg Inst 37:13–32. Cited by Molliver et al. 1973
Boulder Committee (1970) Embryonic vertebrate central nervous system: Revised Terminology. Anat Rec 166:257–262
Bradford R, Parnavelas JG, Lieberman AR (1977) Neurons in layer I of the developing occipital cortex of the rat. J Comp Neurol 176:121–132
Cajal SR (1890) Sobre la existencia de celulas nerviosas especiales en la primera capa de las circunvoluciones cerebrales. Gaceta Medica Catalana. 15 de dicembre, 625–628
Conel L (1930) The postnatal development of the human cerebral cortex. Vol I. The cortex of the newborn. Harvard University Press, p 114
Derer P, Caviness VS, Sidman RL (1977) Early cortical histogenesis in the primary olfactory cortex of the mouse. Brain Res 123:27–40
Duckett S, Pearse AGE (1968) The cells of Cajal-Retzius in the developing human brain. J Anat 102:183–187
Fox MW, Inman O (1966) Persistence of Retzius-Cajal cells in developing dog brain. Brain Res 3:192–194
Gruner JE (1970) The maturation of human cerebral cortex in electron microscopy study of postmortem punctures in premature infants. Biol Neonat 16:243–255
Johnson R, Armstrong-James M (1970) Morphology of superficial postnatal cerebral cortex with special reference to synapses. Z Zellforsch, 110:540–558
König N (1978) Retzius-Cajal or Cajal-Retzius cells? Neuroscience Letters 9:361–363
König N, Roch G, Marty R (1975) The onset of synaptogenesis in rat temporal cortex. Anat Embryol 148:73–87
König N, Valat J, Fulcrand J, Marty R (1977) The time of origin of Cajal-Retzius cells in the rat temporal cortex. An autoradiographic study. Neuroscience Letters 4:21–26
Larroche J-C, Privat A, Jardin L (1981) Some fine structures of the human fetal brain. Sam Levine. International Symposium Paris, Minkowsky (Ed) Karger, Basel, pp 350–358
Marin-Padilla M (1970) Prenatal and early postnatal ontogenesis of the human motor cortex. A golgi study. I. Sequential development of the cortical layers. Brain Res 23:167–183
Marin-Padilla M (1971) Early prenatal ontogenesis of the cerebral cortex (neocortex) of the cat (Felis domestica). A golgi study. I. The primordial neocortical organization. Z Anat Entwickl Gesch 134:117–145
Marin-Padilla M (1972) Prenatal ontogenetic history of the principal neurons of the neocortex of the cat. (Felis domestica) A golgi study. II. Developmental differences and their significances. Z Anat Entwickl Gesch 136:125–142
Marin-Padilla M (1978) Dual origin of the mammalian neocortex and evolution of the cortical plate. Anat Embryol 152:109–126
Meller K, Breipohl W, Glees P (1968) The cytology of the developing molecular layer of mouse motor cortex. An electron microscopical and a Golgi impregnation study. Z Zellforsch 86:171–183
Molliver ME, Van Der Loos H (1970) The ontogenesis of cortical circuitry: the spatial distribution of synapses in somesthetic cortex of newborn dog. Ergebn Anat Entwickl Gesch 42:1–53
Molliver ME, Kostovic I, Van Der Loos H (1973) The development of synapses in cerebral cortex of the human fetus. Brain Res 50:403–407
Poliakov GI (1961) Some results of research into the development of the neuronal structure of the cortical ends of the analysers in man. J Comp Neurol 117:197–213
Povlishock JT (1976) The fine structure of the axons and growth cones of the human fetal cerebral cortex. Brain Res 114:379–389
Privat A (1974) A possible mechanism for the resorption of attachment plates in the growing rat brain. Short communications. Brain Res 69:125–129
Purpura DP (1961) Analysis of axodendritic synaptic organizations in immature cerebral cortex. Ann NY Acad Science 94:604–654
Rabinowicz Th (1964) The cerebral cortex of the premature infant of the 8th month. In: DP Purpura and JP Schadé (Eds) Growth and maturation of the brain. Progress in Brain Research, vol 4:39–92, Elsevier Amsterdam
Readler A, Sievers J (1975) The development of the visual system of the albino rat. Adv Anat Embryol Cell Biol 50:1–88
Raedler A, Sievers J (1976) Light and electron microscopical studies on specific cells of the marginal zone in the developing rat cerebral cortex. Anat Embryol 149:173–181
Raedler E, Raedler A, Feldhaus S (1980) Dynamic aspects of neocortical histogenesis in the rat. Anat Embryol 158:253–269
Retzius G (1891) Ueber den Bau der Oberflächenschicht der Grosshirnrinde beim Menschen und bei den Säugetieren. Verh des Biol Vereins 3:90–102
Rickmann M, Chronwall BM, Wolff JR (1977) On the development of non-pyramidal neurons and axons outside the cortical plate: the early marginal zone as a pallial anlage. Anat Embryol 151:285–307
Sanides D, Sanides F (1974) A comparative Golgi study of the neocortex in insectivores and rodents. Z Mikrosk Anat Forsch Leipzig 88:957–977
Shoukimas G, Hinds JW (1978) The development of the cerebral cortex in the embryonic mouse: an electron microscopic serial section analysis. J Comp Neurol 179:795–830
Sidman RL, Rakic P (1973) Neuronal migration with special reference to the developing human brain. A Review. Brain Res 62:1–35
Sousa-Pinto A, Paula-Barbosa M, Do Carmo-Matos M (1975) A Golgi and electron microscopical study of nerve cells in layer I of the cat auditory cortex. Brain Res 95:443–458
Takashima S, Chan F, Becker LE, Armstrong DL (1980) Morphology of the developing visual cortex of the human infant. A quantitative and qualitative Golgi Study. J Neuropathol Exp Neurol 39:487–501
Voeller K, Pappas GD, Purpura DP (1963) Electron microscope study of development of cat superficial neocortex. Exp Neurol 7:107–130
Wechster W, Meller K (1967) Electron microscopy of neuronal and glial differentiation in the developing brain of the chick. In: Bernhard CG and Schadé JP (Eds) Developmental Neurology. Progress in Brain Research, Vol 26. Elsevier, Amsterdam pp 93–144
Wolff JR (1978) Ontogenetic aspects of cortical architecture lamination. In: Brazier M and Petsche H (Eds) Architectonics of the central cortex. Raven Press, New York pp 149–173
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Larroche, JC. The marginal layer in the neocortex of a 7 week-old human embryo. Anat Embryol 162, 301–312 (1981). https://doi.org/10.1007/BF00299974
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00299974