Concurrent Overproduction of Synapses in Diverse Regions of the Primate Cerebral Cortex

Rakić, Paško; Bourgeois, Jean-Pierre; Eckenhoff, Maryellen F.; Zečević, Nada; Goldman‐Rakic, Patricia S.

doi:10.1126/science.3952506

Cited by 1,065 publications

(650 citation statements)

References 34 publications

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“…One account has to do with the loss of neural plasticity due to massive pruning of synapses and brain cells during childhood (e.g., Rakic, Bourgeois, Zecevic, Eckenhoff, & Goldman-Rakic, 1986), rendering language learners less able to make use of relevant input later in life. Another account has to do with early language experience setting fundamental parameters in the Universal Grammar, thereby heavily influencing subsequent language acquisition (e.g., Chomsky, 1981; see also Pinker, 1994, on both accounts).…”

Section: Discussionmentioning

confidence: 99%

Salvaging a childhood language

Knightly

et al. 2008

Journal of Memory and Language

111

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Childhood experience with a language seems to help adult learners speak it with a more native-like accent. Can analogous benefits be found beyond phonology? This study focused on adult learners of Spanish who had spoken Spanish as their native language before age 7 and only minimally, if at all, thereafter until they began to re-learn Spanish around age 14 years. They were compared with native speakers, childhood overhearers, and typical late-second-language (L2)-learners of Spanish. Both childhood speakers and overhearers spoke Spanish with a more native-like accent than typical late-L2-learners. On grammar measures, childhood speakers-although far from native-like-reliably outperformed childhood overhearers as well as typical late-L2-learners. These results suggest that while simply overhearing a language during childhood could help adult learners speak it with a more native-like phonology, speaking a language regularly during childhood could help re-learners use it with more native-like grammar as well as phonology.

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Section: Discussionmentioning

confidence: 99%

Salvaging a childhood language

Knightly

et al. 2008

Journal of Memory and Language

111

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“…Various data [21] have shown that in early life, the brain initially has a large number of synapses that undergo a period of intense dying off (at approximately 6 -12 years in humans). It is thought that the selection process that determines which synapses are maintained and which ones are eliminated takes place by competitive mechanisms.…”

Section: Discussionmentioning

confidence: 99%

Cortical plasticity in an early blind musician: an fMRl study

Ross

Olson

Gore

2003

Magnetic Resonance Imaging

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Many studies have examined tactile perception and simple auditory perception in the blind, but none have previously investigated the neural basis of musical ability in this group. This topic is of particular interest because it has been suggested that early blind individuals may possess advanced musical skills (such as absolute pitch). Presumably, these skills could be the result of neural plasticity. It has been hard to empirically assess this claim because of the difficulty in recruiting an adequate number of subjects for use in a conventional paradigm. In the present paper, we report data from a congenitally blind musician, subject ML. Behavioral tests show that she possessed absolute pitch abilities that were similar to those of a reference group of AP musicians with normal vision. To examine the neural basis of her abilities we then tested subject ML and five control subjects using an fMRI paradigm. A regions-of-interest analysis found that similar areas (the right secondary auditory cortex, left IFG, left SMG) were activated in ML and the control subjects, to a similar degree, in response to music processing. However, ML showed additional activations in left parietal association cortices and extrastriate regions of the occipital lobe. Subject ML's data are consistent with a vast body of literature on blindness-induced plasticity. They extend these findings by demonstrating that cortical plasticity may underlie special musical skills as well. These data illustrate the potential value of case studies to investigate particularly rare phenotypes.

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“…Another event that does not fit the model is a coordinated surge in synaptogenesis, an event apparently linked just prior to an onslaught of experience. This phenomenon begins just prior to birth in primates and just prior to exit from the nest in rats (Bates et al, 2002;Blue and Parnavelas, 1983;Huttenlocher and Dabholkar, 1997;Rakic et al, 1986;Zecevic and Rakic, 1991). A similar link to birth is found in some respiratory, cardiovascular and digestive functions, linked to the demands of extrauterine survival.…”

Section: Exceptions and Limitationsmentioning

confidence: 93%

Extrapolating brain development from experimental species to humans

et al. 2007

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To better understand the neurotoxic effects of diverse hazards on the developing human nervous system, researchers and clinicians rely on data collected from a number of model species that develop and mature at varying rates. We review the methods commonly used to extrapolate the timing of brain development from experimental mammalian species to humans, including morphological comparisons, "rules of thumb" and "event-based" analyses. Most are unavoidably limited in range or detail, many are necessarily restricted to rat/human comparisons, and few can identify brain regions that develop at different rates. We suggest this issue is best addressed using "neuroinformatics", an analysis that combines neuroscience, evolutionary science, statistical modeling and computer science. A current use of this approach relates numeric values assigned to ten mammalian species and hundreds of empirically derived developing neural events, including specific evolutionary advances in primates. The result is an accessible, online resource (http:// www.translatingtime.net/) that can be used to equate dates in the neurodevelopmental literature across laboratory species to humans, predict neurodevelopmental events for which data are lacking in humans, and help to develop clinically relevant experimental models.

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Concurrent Overproduction of Synapses in Diverse Regions of the Primate Cerebral Cortex

Cited by 1,065 publications

References 34 publications

Salvaging a childhood language

Salvaging a childhood language

Cortical plasticity in an early blind musician: an fMRl study

Extrapolating brain development from experimental species to humans

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