Key Points
-
What is developmental exuberance? The exuberant development of neural circuits involves: the formation of long, transient axonal projections; the overproduction of short axonal branches and synapses, including polyinnervation and/or peaks of synaptic density; and the overproduction of dendritic branches and/or spines. In all cases, selection eventually leads to maintenance of some of the juvenile structures and elimination of others.
-
What function do exuberant structures have before their elimination? Some transient structures have important functions in constructing circuitry, but for others it is less clear whether the eliminated structures have important functions other than being substrates for the actions of selective mechanisms.
-
How general is the phenomenon? Development by exuberance is widespread during the formation of cerebral cortical circuits. It has been reported across different species and for different areas and projections, which suggests that it might have been a distinctive feature of mammalian development throughout evolution.
-
How are the projections eliminated? Two mechanisms can result in the elimination of the transient projections: neuronal death, or selective deletion of axons, axonal branches and/or synapses. The data available for the axonal pathways that interconnect cerebral cortical areas indicate a prevalent or exclusive role for the second mechanism.
-
What is the magnitude of elimination? The size of the elimination has been quantified for synapses and some long axonal tracts using electron microscopy. Less stringent quantification is available from experiments with axonal tracers. Studies show that some juvenile tracts are eliminated completely later in life.
-
Exuberant development of cortical connections occurs within boundaries established by the selective growth of axons from certain classes of neuron to specific targets, probably on the basis of selective molecular affinities. Once the axons have reached the proximity of their targets, selection occurs, particularly in the region of the cortical subplate.
-
The formation of the terminal axonal arbors in the targets is followed by continued exuberance and selection of axonal branches and synapses but within increasingly restricted topographical boundaries. The synaptic boutons are, from the onset, selectively distributed in the columnar and laminar dimensions, although their number exceeds that seen in adults.
-
Factors that control axonal selection include signals from the periphery (such as the retina), thyroid hormones, competition among axonal systems and/or between neurons for chemotrophic substances present in the target structure, and the expression of molecules that identify targets as appropriate to retain persistent innervation. This epigenetic control allows modification of the cortical networks in the light of changes in brain structure brought about by epigenetic or genetic changes.
-
The aetiology of neurological and psychiatric conditions such as dyslexia, attention deficit hyperactivity disorder and schizophrenia might involve abnormal growth and/or selection of cortical connections in the developing brain. Encouraging results for the study of cortical connectivity in the human brain have been provided by new developments in brain imaging and by tools for studying the dynamics of neuronal assemblies in the cerebral cortex.
Abstract
The cerebral cortex is the largest and most intricately connected part of the mammalian brain. Its size and complexity has increased during the course of evolution, allowing improvements in old functions and causing the emergence of new ones, such as language. This has expanded the behavioural and cognitive repertoire of different species and has determined their competitive success. To allow the relatively rapid emergence of large evolutionary changes in a structure of such importance and complexity, the mechanisms by which cortical circuitry develops must be flexible and yet robust against changes that could disrupt the normal functions of the networks.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
£119.00 per year
only £9.92 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Innocenti, G. M., Fiore, L. & Caminiti, R. Exuberant projection into the corpus callosum from the visual cortex of newborn cats. Neurosci. Lett. 4, 237–242 (1977).
Innocenti, G. M. The development of projections from cerebral cortex. Prog. Sens. Physiol. 12, 65–114 (1991).
O'Leary, D. D. M. Development of connectional diversity and specificity in the mammalian brain by the pruning of collateral projections. Curr. Opin. Neurobiol. 2, 70–77 (1992). An important review that complements this one, describing how the pruning of collateral projections first became recognized as a fundamental and widespread mechanism for the development of specific axonal connections.
Stanfield, B. B. The development of the corticospinal projection. Prog. Neurobiol. 38, 169–202 (1992). Another important review describing early studies of exuberance in the rodent's developing corticospinal system, which became established as a powerful model in this field.
Naegele, J. R., Jhaveri, S. & Schneider, G. E. Sharpening of topographical projections and maturation of geniculocortical axon arbors in the hamster. J. Comp. Neurol. 277, 593–607 (1988).
Catalano, S. M., Robertson, R. T. & Killackey, H. P. Individual axon morphology and thalamocortical topography in developing rat somatosensory cortex. J. Comp. Neurol. 367, 36–53 (1996).
Rakic, P. Prenatal genesis of connections subserving ocular dominance in the rhesus monkey. Nature 261, 467–471 (1976).
LeVay, S., Stryker, M. P. & Shatz, C. Ocular dominance columns and their development in layer IV of the cat's visual cortex: a quantitative study. J. Comp. Neurol. 179, 223–244 (1978).
Crowley, J. C. & Katz, L. C. Early development of ocular dominance columns. Science 290, 1321–1324 (2000).
Crair, M. C., Horton, J. C., Antonini, A. & Stryker, M. P. Emergence of ocular dominance columns in cat visual cortex by 2 weeks of age. J. Comp. Neurol. 430, 235–249 (2001).
Crowley, J. C. & Katz, L. C. Ocular dominance development revisited. Curr. Opin. Neurobiol. 12, 104–109 (2002).
Antonini, A. & Stryker, M. P. Development of individual geniculocortical arbors in cat striate cortex and effects of binocular impulse blockade. J. Neurosci. 13, 3549–3573 (1993).
Innocenti, G. & Clarke, S. Bilateral transitory projection to visual areas from the auditory cortex in kittens. Dev. Brain Res. 14, 143–148 (1984).
Price, D. J. & Blakemore, C. Regressive events in the postnatal development of association projections in the visual cortex. Nature 316, 721–724 (1985).
Webster, M. J., Ungerleider, L. G. & Bachevalier, J. Connections of inferior temporal areas TE and TEO with medial temporal-lobe structures in infant and adult monkeys. J. Neurosci. 11, 1095–1116 (1991). This remains one of the most striking examples of exuberant cortical connections in the monkey.
Assal, F. & Innocenti, G. M. Transient intra-areal axons in developing cat visual cortex. Cereb. Cortex 3, 290–303 (1993).
Galuske, R. A. W. & Singer, W. The origin and topography of long-range intrinsic projections in cat visual cortex: a developmental study. Cereb. Cortex 6, 417–430 (1996).
Callaway, E. M. Prenatal development of layer-specific local circuits in primary visual cortex of the macaque monkey. J. Neurosci. 18, 1505–1527 (1998).
Barone, P., Dehay, C., Berland, M. & Kennedy, H. Role of directed growth and target selection in the formation of cortical pathways: prenatal development of the projection of area V2 to area V4 in the monkey. J. Comp. Neurol. 374, 1–20 (1996).
Distel, H. & Holländer, H. Autoradiographic tracing of developing subcortical projections of the occipital region in fetal rabbits. J. Comp. Neurol. 192, 505–518 (1980).
Stanfield, B. B., O'Leary, D. D. M. & Fricks, C. Selective collateral elimination in early postnatal development restricts cortical distribution of rat pyramidal tract neurones. Nature 298, 371–373 (1982).
Curfs, M. H. J. M., Gribnau, A. A. M. & Dederen, P. J. W. C. Selective elimination of transient corticospinal projections in the rat cervical spinal cord gray matter. Dev. Brain Res. 78, 182–190 (1994).
Galea, M. P. & Darian-Smith, I. Postnatal maturation of the direct corticospinal projection in the macaque monkey. Cereb. Cortex 5, 518–540 (1995).
Murakami, F., Kobayashi, Y., Uratani, T. & Tamada, A. Individual corticorubral neurons project bilaterally during postnatal development and following early contralateral cortical lesions. Exp. Brain Res. 96, 181–193 (1993).
Del Caño, G. G., Gerrikagoitia, I., Goñi, O. & Martínez-Millán, L. Sprouting of the visual corticocollicular terminal field after removal of contralateral retinal inputs in neonatal rabbits. Exp. Brain Res. 117, 399–410 (1997).
Metin, C. & Godement, P. The ganglionic eminence may be an intermediate target for corticofugal and thalamocortical axons. J. Neurosci. 16, 3219–3235 (1996).
Molnar, Z., Adams, R. & Blakemore, C. Mechanisms underlying the early establishment of thalamocortical connections in the rat. J. Neurosci. 18, 5723–5745 (1998).
Braisted, J. E., Tuttle, R. & O'Leary, D. D. Thalamocortical axons are influenced by chemorepellent and chemoattractant activities localized to decision points along their path. Dev. Biol. 208, 430–440 (1999).
Tuttle, R., Nakagawa, Y., Johnson, J. E. & O'Leary, D. D. Defects in thalamocortical axon pathfinding correlate with altered cell domains in Mash-1-deficient mice. Development 126, 1903–1916 (1999).
Pratt, T. et al. Disruption of early events in thalamocortical tract formation in mice lacking the transcription factors Pax6 or Foxg1. J. Neurosci. 22, 8523–8531 (2002).
Allendoerfer, K. L. & Shatz, C. J. The subplate, a transient neocortical structure: its role in the development of connections between thalamus and cortex. Annu. Rev. Neurosci. 17, 185–218 (1994).
Price, D. J., Aslam, S., Tasker, L. & Gillies, K. Fates of the earliest generated cells in the developing murine neocortex. J. Comp. Neurol. 377, 414–422 (1997).
Lopez-Bendito, G. & Molnar, Z. Thalamocortical development: how are we going to get there? Nature Rev. Neurosci. 4, 276–289 (2003).
Friauf, E., McConnell, S. K. & Shatz, C. J. Functional synaptic circuits in the subplate during fetal and early postnatal development of cat visual cortex. J. Neurosci. 10, 2601–2613 (1990).
Herrmann, K., Antonini, A. & Shatz, C. J. Ultrastructural evidence for synaptic interactions between thalamocortical axons and subplate neurons. Eur. J. Neurosci. 6, 1729–1742 (1994).
Hanganu, I. L., Kilb, W. & Luhmann, H. J. Functional synaptic projections onto subplate neurons in neonatal rat somatosensory cortex. J. Neurosci. 22, 7165–7176 (2002).
Ghosh, A. & Shatz, C. J. Involvement of subplate neurons in the formation of ocular dominance columns. Science 255, 1441–1443 (1992).
Kanold, P. O., Kara, P., Reid, R. C. & Shatz, C. J. Role of subplate neurons in functional maturation of visual cortical columns. Science 301, 521–525 (2003).
Rakic, P., Bourgeois, J. -P., Eckenhoff, M. F., Zecevic, N. & Goldman-Rakic, P. S. Concurrent overproduction of synapses in diverse regions of the primate cerebral cortex. Science 232, 232–235 (1986). A seminal paper on exuberant and synchronous synaptogenesis in different cortical areas of the monkey.
Aggoun-Zouaoui, D., Kiper, D. C. & Innocenti, G. M. Growth of callosal terminal arbors in primary visual areas of the cat. Eur. J. Neurosci. 8, 1132–1148 (1996).
Bressoud, R. & Innocenti, G. M. Topology, early differentiation and exuberant growth of a set of cortical axons. J. Comp. Neurol. 406, 87–108 (1999). Documents exuberant development of individual axonal arbors and ways in which exuberant development is constrained by what seems to be specific growth of different axonal types.
Luhmann, H. J., Greuel, J. M. & Singer, W. Horizontal interactions in cat striate cortex: III. Ectopic receptive fields and transient exuberance of tangential interactions. Eur. J. Neurosci. 2, 369–377 (1990).
Chen, B., Boukamel, K., Kao, J. P. Y. & Roerig, B. Spatial distribution of inhibitory synaptic connections during development of ferret primary visual cortex. Exp. Brain Res. 160, 496–509 (2005).
Curfs, M. H. J. M., Gribnau, A. A. M., Dederen, P. J. W. C. & Bergervoet-Vernooij, H. W. M. Transient functional connections between the developing corticospinal tract and cervical spinal interneurons as demonstrated by c-fos immunohistochemistry. Dev. Brain Res. 87, 214–219 (1995).
Innocenti, G. M. Exuberant development of connections, and its possible permissive role in cortical evolution. Trends Neurosci. 18, 397–402 (1995).
Innocenti, G. M. Growth and reshaping of axons in the establishment of visual callosal connections. Science 212, 824–827 (1981).
Lotto, R. B., Asavaritikrai, P., Vali, L. & Price, D. J. Target-derived neurotrophic factors regulate the death of developing forebrain neurons after a change in their trophic requirements. J. Neurosci. 21, 3904–3910 (2001).
Aggoun-Zouaoui, D. & Innocenti, G. M. Juvenile visual callosal axons in kittens display origin- and fate-related morphology and distribution of arbors. Eur. J. Neurosci. 6, 1846–1863 (1994).
Berbel, P. & Innocenti, G. M. The development of the corpus callosum in cats: a light- and electron-microscopic study. J. Comp. Neurol. 276, 132–156 (1988).
LaMantia, A. -S. & Rakic, P. Axon overproduction and elimination in the corpus callosum of the developing rhesus monkey. J. Neurosci. 10, 2156–2175 (1990).
Kadhim, H. J., Bhide, P. G. & Frost, D. O. Transient axonal branching in the developing corpus callosum. Cereb. Cortex 3, 551–566 (1993).
Innocenti, G. M. & Clarke, S. The organization of immature callosal connections. J. Comp. Neurol. 230, 287–309 (1984).
Price, D. J., Ferrer, J. M., Blakemore, C. & Kato, N. Postnatal development and plasticity of corticocortical projections from area 17 to area 18 in the cat's visual cortex. J. Neurosci. 14, 2747–2762 (1994).
Caric, D. & Price, D. J. The organization of visual corticocortical connections in early postnatal kittens. Neuroscience 73, 817–829 (1996).
Innocenti, G. M., Berbel, P. & Clarke, S. Development of projections from auditory to visual areas in the cat. J. Comp. Neurol. 272, 242–259 (1988).
Kennedy, H., Bullier, J. & Dehay, C. Transient projection from the superior temporal sulcus to area 17 in the newborn macaque monkey. Proc. Natl Acad. Sci. USA 86, 8093–8097 (1989).
Meissirel, C., Dehay, C., Berland, M. & Kennedy, H. Segregation of callosal and association pathways during development in the visual cortex of the primate. J. Neurosci. 11, 3297–3316 (1991).
Innocenti, G. M. & Clarke, S. Multiple sets of visual cortical neurons projecting transitorily through the corpus callosum. Neurosci. Lett. 41, 27–32 (1983).
Koester, S. E. & O'Leary, D. D. M. Connectional distinction between callosal and subcortical projecting cortical neurons is determined prior to axon extension. Dev. Biol. 160, 1–14 (1993).
Ding, S. -L. & Elberger, A. J. Confirmation of the existence of transitory corpus callosum axons in area 17 of neonatal cat: an anterograde tracing study using biotinylated dextran amine. Neurosci. Lett. 177, 66–70 (1994).
Kuang, R. Z. & Kalil, K. Development of specificity in corticospinal connections by axon collaterals branching selectively into appropriate spinal targets. J. Comp. Neurol. 344, 270–282 (1994).
Woo, T. U., Pucak, M. L., Kye, C. M., Matus, C. V. & Lewis, D. A. Peripubertal refinement of the intrinsic and associational circuitry in monkey prefrontal cortex. Neuroscience 80, 1149–1158 (1997).
Riederer, B. M. & Innocenti, G. M. Differential distribution of Tau proteins in developing cat cerebral cortex and corpus callosum. Eur. J. Neurosci. 3, 1134–1145 (1991).
Riederer, B. M., Berbel, P. & Innocenti, G. M. Neurons in the corpus callosum of the cat during postnatal development. Eur. J. Neurosci. 19, 2039–2046 (2004).
Norris, C. R. & Kalil, K. Guidance of callosal axons by radial glia in the developing cerebral cortex. J. Neurosci. 11, 3481–3492 (1991).
Shatz, C. J. Anatomy of interhemispheric connections in the visual system of Boston Siamese and ordinary cats. J. Comp. Neurol. 173, 497–518 (1977).
Tremblay, F., Ptito, M., Miceli, D. & Guillemot, J. -P. Distribution of visual callosal projection neurons in the siamese cat: an HRP study. J. Hirnforsch. 28, 491–503 (1987).
Innocenti, G. M. & Frost, D. O. Effects of visual experience on the maturation of the efferent system to the corpus callosum. Nature 280, 231–234 (1979).
Innocenti, G. M. & Frost, D. O. The postnatal development of visual callosal connections in the absence of visual experience or of the eyes. Exp. Brain Res. 39, 365–375 (1980).
Frost, D. O. & Moy, Y. P. Effects of dark rearing on the development of visual callosal connections. Exp. Brain Res. 78, 203–213 (1989).
Boire, D., Morris, R., Ptito, M., Lepore, F. & Frost, D. O. Effects of neonatal splitting of the optic chiasm on the development of feline visual callosal connections. Exp. Brain Res. 104, 275–286 (1995).
Price, D. J., Ferrer, J. M. R., Blakemore, C. & Kato, N. Postnatal development and plasticity of corticocortical projections from area 17 to area 18 in the cat's visual cortex. J. Neurosci. 14, 2747–2762 (1994).
Caric, D. & Price, D. J. Evidence that the lateral geniculate nucleus regulates the normal development of visual corticocortical projections in the cat. Exp. Neurol. 156, 353–362 (1999). Obtained direct evidence from lesion experiments that showed the role of thalamocortical connections in the selection of cortico-cortical afferents from the initial exuberant stock.
Olavarria, J. F. & Van Sluyters, R. C. Overall pattern of callosal connections in visual cortex of normal and enucleated cats. J. Comp. Neurol. 363, 161–176 (1995).
Olavarria, J. F. The effect of visual deprivation on the number of callosal cells in the cat is less pronounced in extrastriate cortex than in the 17/18 border region. Neurosci. Lett. 195, 147–150 (1995).
Zufferey, P. D., Jin, F., Nakamura, H., Tettoni, L. & Innocenti, G. The role of pattern vision in the development of cortico-cortical connections. Eur. J. Neurosci. 11, 2669–2688 (1999).
Innocenti, G. M., Frost, D. O. & Illes, J. Maturation of visual callosal connections in visually deprived kittens: a challenging critical period. J. Neurosci. 5, 255–267 (1985).
Manger, P. R. et al. The representation of the visual field in three extrastriate areas of the ferret (Mustela putorius) and the relationship of retinotopy and field boundaries to callosal connectivity. Cereb. Cortex 12, 423–437 (2002).
Olavarria, J. F. Callosal connections correlate preferentially with ipsilateral cortical domains in cat area 17 and 18, and with contralateral domains in the 17/18 transition zone. J. Comp. Neurol. 433, 441–457 (2001). This work makes an important contribution to the concept that the topographic projections from the retina guide the establishment of callosal connections.
Restrepo, C. E., Manger, P. R., Spenger, C. & Innocenti, G. M. Immature cortex lesions alter retinotopic maps and interhemispheric connections. Ann. Neurol. 54, 51–65 (2003). A recent paper that confirms and extends the concept that competition among cortico-cortical axons is involved in shaping cortico-cortical networks.
Lotto, R. B., Asavaritikrai, P., Vali, L. & Price, D. J. Target-derived neurotrophic factors regulate the death of developing forebrain neurons after a change in their trophic requirements. J. Neurosci. 21, 3904–3910 (2001).
Webster, M. J., Ungerleider, L. G. & Bachevalier, J. Lesions of inferior temporal area TE in infant monkeys alter cortico-amygdalar projections. Neuroreport 2, 769–772 (1991).
Webster, M. J. & Bachevalier, J. in Emotion, Memory and Behavior (ed. Nakajima, T.) 3–15 (CRC, USA, 1995).
Gravel, C., Sasseville, R. & Hawkes, R. Maturation of the corpus callosum of the rat: II. Influence of thyroid hormones on the number and maturation of axons. J. Comp. Neurol. 291, 147–161 (1990).
Berbel, P. et al. Organization of auditory callosal connections in hypothyroid adult rats. Eur. J. Neurosci. 5, 1465–1478 (1993).
Li, C. -P., Olavarria, J. F. & Greger, B. E. Occipital cortico-pyramidal projection in hypothyroid rats. Dev. Brain Res. 89, 227–234 (1995).
Miller, M. W., Astley, S. J. & Clarren, S. K. Number of axons in the corpus callosum of the mature Macaca nemestrina: increases caused by prenatal exposure to ethanol. J. Comp. Neurol. 412, 123–131 (1999).
Bishop, K. M., Goudreau, G. & O'Leary, D. D. Regulation of area identity in the mammalian neocortex by Emx2 and Pax6. Science 288, 344–349 (2000).
Bishop, K. M., Garel, S., Nakagawa, Y., Rubenstein, J. L. & O'Leary, D. D. Emx1 and Emx2 cooperate to regulate cortical size, lamination, neuronal differentiation, development of cortical efferents, and thalamocortical pathfinding. J. Comp. Neurol. 457, 345–360 (2003).
Huffman, K. J., Garel, S. & Rubenstein, J. L. R. Fgf8 regulates the development of intra-neocortical projections. J. Neurosci. 24, 8917–8923 (2004).
Clarke, S., Kraftsik, R., Van der Loos, H. & Innocenti, G. M. Forms and measures of adult and developing human corpus callosum: is there sexual dimorphism? J. Comp. Neurol. 280, 213–230 (1989).
DeLacoste-Utamsing, C. & Holloway, R. L. Sexual dimorphism in the human corpus callosum. Science 216, 1431–1432 (1982).
Kim, J. H. Y. & Juraska, J. M. Sex differences in the development of axon number in the splenium of the rat corpus callosum from postnatal day 15 through 60. Dev. Brain Res. 102, 77–85 (1997).
Nunez, J. L., Nelson, J., Pych, J. C., Kim, J. H. Y. & Juraska, J. M. Myelination in the splenium of the corpus callosum in adult male and female rats. Dev. Brain Res. 120, 87–90 (2000).
Bishop, K. M. & Wahlsten, D. Sex differences in the human corpus callosum: myth or reality? Neurosci. Biobehav. Rev. 21, 581–601 (1997).
Dubb, A., Gur, R., Avants, B. & Gee, J. Characterization of sexual dimorphism in the human corpus callosum. Neuroimage 20, 512–519 (2003).
Hwang, S. J. et al. Gender differences in the corpus callosum of neonates. Neuroreport 15, 1029–1032 (2004).
Witelson, S. F. The brain connection: the corpus callosum is larger in left-handers. Science 229, 665–668 (1985).
Witelson, S. F. & Goldsmith, C. H. The relationship of hand preference to anatomy of the corpus callosum in men. Brain Res. 545, 175–182 (1991).
Habib, M. et al. Effects of handedness and sex on the morphology of the corpus callosum: a study with brain magnetic resonance imaging. Brain Cogn. 16, 41–61 (1991).
Giedd, J. N. et al. Quantitative morphology of the corpus callosum in attention deficit hyperactivity disorder. Am. J. Psychiatry 151, 665–669 (1994).
Magara, F., Ricceri, L., Wolfer, D. P. & Lipp, H. -P. The acallosal mouse strain I/LnJ: a putative model of ADHD? Neurosci. Biobehav. Rev. 24, 45–50 (2000).
von Plessen, K. et al. Less developed corpus callosum in dyslexic subjects—a structural MRI study. Neuropsychologia 40, 1035–1044 (2002).
Innocenti, G. M., Ansermet, F. & Parnas, J. Schizophrenia, neurodevelopment and corpus callosum. Mol. Psychiatry 8, 261–274 (2003).
Portera-Calliau, C., Weimer, R. W., De Paola, V., Caroni, P. & Svoboda, K. Diverse modes of axon elaboration in the developing neocortex. PLoS Biol. 3, e272 (2005).
Bagri, A. Cheng, H. J., Yaron, A., Pleasure, S. J. & Tessier-Lavigne, M. Stereotyped pruning of long hippocampal axon branches triggered by retraction inducers of the semaphoring family. Cell 113, 285–299 (2003).
Ernst, A. F., Gallo, G., Letourneau, P. C. & McLoon, S. Stabilization of growing retinal axons by the combined signalling of nitric oxide and brain-derived neurotrophic factor. J. Neurosci. 20, 1458–1469 (2000).
McLaughlin, T., Hindges, R., Yates, P. A. & O'Leary, D. D. M. Bifunctional action of ephrin-B1 as a repellent and attractant to control bidirectional branch extension in dorso-ventral retinotopic mapping. Development 130, 2407–2418 (2003).
McLaughlin, T., Torborg, C. L., Feller, M. B. & O'Leary, D. D. M. Retinotopic map refinement requires spontaneous retinal waves during a brief critical period of development. Neuron 40, 1147–1160 (2003).
Muzio, L. & Mallamaci, A. Emx1, Emx2 and Pax6 in specification, regionalization and arealization of the cerebral cortex. Cereb. Cortex. 13, 641–647 (2003).
Nakayama, A. Y., Harms, M. B. & Luo, L. Small GTPases Rac and Rho in the maintenance of dendritic spines and branches in hippocampal pyramidal neurons. J. Neurosci. 20, 5329–5338 (2000).
Tettoni, L., Gheorghita-Baechler, F., Bressoud, R., Welker, E. & Innocenti, G. M. Constant and variable aspects of axonal phenotype in cerebral cortex. Cereb. Cortex 8, 543–552 (1998). Shows that, surprisingly, axons from different species, systems and those that form different types of connection share several common features and relatively few variations of a common 'Bauplan'.
Thomson, A. M. & Morris, O. T. Selectivity in the inter-laminar connections made by neocortical neurons. J. Neurocytol. 31, 239–246 (2002).
Lein, S. & Shatz, C. J. Rapid regulation of brain-derived neurotrophic factor mRNA within eye-specific circuits during ocular dominance column formation. J. Neurosci. 20, 1470–1483 (2000).
Bengtsson, S. I. et al. Extensive piano practicing has regionally specific effects on white matter development. Nature Neurosci. 8, 1148–1150 (2005).
Shepherd, G. M. G., Stepanyants, A., Bureau, I., Chklovskii, D. & Svoboda, K. Geometric and functional organization of cortical circuits. Nature Neurosci. 8, 782–790 (2005).
Klingberg, T. et al. Microstructure of temporo-parietal white matter as a basis for reading ability: evidence from diffusion tensor magnetic resonance imaging. Neuron 25, 493–500 (2000).
Zhang, J. et al. Mapping postnatal mouse brain development with diffusion tensor microimaging. Neuroimage 26, 1042–1051 (2005).
Snook, L., Paulson, L. A., Roy, D., Phillips, L. & Beaulieu, C. Diffusion tensor imaging of neurodevelopment in children and young adults. Neuroimage 26, 1164–1173 (2005).
Saleem, K. S. et al. Magnetic resonance imaging of neuronal connections in the macaque monkey. Neuron 34, 685–700 (2002).
Knyazeva, M. G. & Innocenti, G. M. EEG coherence studies in the normal brain and after early-onset cortical pathologies. Brain Res. Rev. 36, 119–128 (2001).
Carmeli, C., Knyazeva, M. G., Innocenti, G. & De Feo, O. Assessment of EEG synchronization based on state-space analysis. Neuroimage 25, 339–354 (2005).
Knyazeva, M. G., Fornari, E., Meuli, R., Innocenti, G. M. & Maeder, P. Imaging a synchronous neuronal assembly in the visual brain. Neuroimage 20 Sep 2005 [epub ahead of print].
Innocenti, G. M., Maeder, P., Knyazeva, M., Fornari, E. & Deonna, T. Functional activation of microgyric visual cortex in man. Ann. Neurol. 50, 672–676 (2001).
Zesiger, P., Kiper, D., Deonna, T. & Innocenti, G. M. Preserved visual function in a case of occipito-parietal microgyria. Ann. Neurol. 52, 492–498 (2002).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Related links
Glossary
- TARGET
-
(of growing axons). The site, or structure, towards which an axon grows — ultimately one or more neurons.
- OCULAR DOMINANCE
-
The neuronal property of responding preferentially to stimuli presented to one eye or the other.
- TRACER
-
A tracer denotes a substance that is actively transported or diffuses along axons. Anterograde tracers move from neuronal cell bodies towards axon terminals, whereas retrograde tracers move from axon terminals (or damaged axons) towards neuronal cell bodies. Many tracers move in both directions.
- TELENCEPHALON
-
One of the major components of the forebrain; thalamocortical axons grow through its ventral part to reach its dorsal part, where the cerebral cortex forms.
- DIENCEPHALON
-
The component of the forebrain in which the thalamus develops.
- PIONEER PROJECTIONS
-
(Or axons). Axons that precede the growth of others to a given target, and are thought to guide later-growing projections.
- RECEPTIVE FIELD
-
A region in the periphery that, when stimulated in an appropriate way, produces a response in a particular sensory neuron.
- GROWTH CONE
-
A highly dynamic structure at the growing end of an axon (or dendrite) that steers axonal (or dendritic) growth by decoding cues in the environment.
Rights and permissions
About this article
Cite this article
Innocenti, G., Price, D. Exuberance in the development of cortical networks. Nat Rev Neurosci 6, 955–965 (2005). https://doi.org/10.1038/nrn1790
Published:
Issue Date:
DOI: https://doi.org/10.1038/nrn1790
This article is cited by
-
Selective plasticity of callosal neurons in the adult contralesional cortex following murine traumatic brain injury
Nature Communications (2022)
-
Handedness and midsagittal corpus callosum morphology: a meta-analytic evaluation
Brain Structure and Function (2022)
-
Individual variability in the nonlinear development of the corpus callosum during infancy and toddlerhood: a longitudinal MRI analysis
Brain Structure and Function (2022)
-
Correction to: Modeling Axonal Plasticity in Artificial Neural Networks
Neural Processing Letters (2021)
-
Modeling Axonal Plasticity in Artificial Neural Networks
Neural Processing Letters (2021)