201
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Sagi Y, Tavor I, Hofstetter S, Tzur-Moryosef S, Blumenfeld-Katzir T, Assaf Y. Learning in the fast lane: new insights into neuroplasticity. Neuron 2012; 73:1195-203. [PMID: 22445346 DOI: 10.1016/j.neuron.2012.01.025] [Citation(s) in RCA: 328] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2012] [Indexed: 02/08/2023]
Abstract
The timescale of structural remodeling that accompanies functional neuroplasticity is largely unknown. Although structural remodeling of human brain tissue is known to occur following long-term (weeks) acquisition of a new skill, little is known as to what happens structurally when the brain needs to adopt new sequences of procedural rules or memorize a cascade of events within minutes or hours. Using diffusion tensor imaging (DTI), an MRI-based framework, we examined subjects before and after a spatial learning and memory task. Microstructural changes (as reflected by DTI measures) of limbic system structures (hippocampus and parahippocampus) were significant after only 2 hr of training. This observation was also found in a supporting rat study. We conclude that cellular rearrangement of neural tissue can be detected by DTI, and that this modality may allow neuroplasticity to be localized over short timescales.
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Affiliation(s)
- Yaniv Sagi
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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202
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Zatorre RJ, Fields RD, Johansen-Berg H. Plasticity in gray and white: neuroimaging changes in brain structure during learning. Nat Neurosci 2012; 15:528-36. [PMID: 22426254 PMCID: PMC3660656 DOI: 10.1038/nn.3045] [Citation(s) in RCA: 1105] [Impact Index Per Article: 92.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Human brain imaging has identified structural changes in gray and white matter that occur with learning. However, ascribing imaging measures to underlying cellular and molecular events is challenging. Here we review human neuroimaging findings of structural plasticity and then discuss cellular and molecular level changes that could underlie observed imaging effects. Greater dialog between researchers in these different fields would help to facilitate cross-talk between cellular and systems level explanations of how learning sculpts brain structure.
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Affiliation(s)
- Robert J Zatorre
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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203
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Wenger E, Schaefer S, Noack H, Kühn S, Mårtensson J, Heinze HJ, Düzel E, Bäckman L, Lindenberger U, Lövdén M. Cortical thickness changes following spatial navigation training in adulthood and aging. Neuroimage 2012; 59:3389-97. [DOI: 10.1016/j.neuroimage.2011.11.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 10/29/2011] [Accepted: 11/04/2011] [Indexed: 10/15/2022] Open
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204
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ten Brink M, Ghazanfar A. Social Neuroscience: More Friends, More Problems…More Gray Matter? Curr Biol 2012; 22:R84-5. [DOI: 10.1016/j.cub.2011.12.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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205
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Sallet J, Mars RB, Noonan MP, Andersson JL, O'Reilly JX, Jbabdi S, Croxson PL, Jenkinson M, Miller KL, Rushworth MFS. Social network size affects neural circuits in macaques. Science 2012; 334:697-700. [PMID: 22053054 DOI: 10.1126/science.1210027] [Citation(s) in RCA: 289] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
It has been suggested that variation in brain structure correlates with the sizes of individuals' social networks. Whether variation in social network size causes variation in brain structure, however, is unknown. To address this question, we neuroimaged 23 monkeys that had been living in social groups set to different sizes. Subject comparison revealed that living in larger groups caused increases in gray matter in mid-superior temporal sulcus and rostral prefrontal cortex and increased coupling of activity in frontal and temporal cortex. Social network size, therefore, contributes to changes both in brain structure and function. The changes have potential implications for an animal's success in a social context; gray matter differences in similar areas were also correlated with each animal's dominance within its social network.
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Affiliation(s)
- J Sallet
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.
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206
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Ellegood J, Henkelman RM, Lerch JP. Neuroanatomical Assessment of the Integrin β3 Mouse Model Related to Autism and the Serotonin System Using High Resolution MRI. Front Psychiatry 2012; 3:37. [PMID: 22557981 PMCID: PMC3337465 DOI: 10.3389/fpsyt.2012.00037] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/09/2012] [Indexed: 12/02/2022] Open
Abstract
The integrinβ3 (ITGβ3) gene has been associated with both autism and the serotonin system. The purpose of this study was to examine the volumetric differences in the brain of an ITGβ3 homozygous knockout mouse model compared with a corresponding wild-type mouse using high resolution magnetic resonance imaging and detailed statistical analyses. The most striking difference found was an 11% reduction in total brain volume. Moreover, 32 different regions were found to have significantly different relative volumes (percentage total brain volume) in the ITGβ3 mouse. A number of interesting differences relevant to autism were discovered including a smaller corpus callosum volume and bilateral decreases in the hippocampus, striatum, and cerebellum. Relative volume increases were also found in the frontal and parieto-temporal lobes as well as in the amygdala. Particularly intriguing were the changes in the lateral wings of the dorsal raphe nuclei since that nucleus is so integral to the development of many different brain regions and the serotonin system in general.
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Affiliation(s)
- Jacob Ellegood
- Mouse Imaging Centre, Hospital for Sick Children Toronto, ON, Canada
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207
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Remodeling human cortex through training: comment on May. Trends Cogn Sci 2011; 16:96-7; author reply 97-8. [PMID: 22209598 DOI: 10.1016/j.tics.2011.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 12/06/2011] [Indexed: 11/20/2022]
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208
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Lillard AS, Erisir A. Old Dogs Learning New Tricks: Neuroplasticity Beyond the Juvenile Period. DEVELOPMENTAL REVIEW 2011; 31:207-239. [PMID: 24648605 PMCID: PMC3956134 DOI: 10.1016/j.dr.2011.07.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Twenty years ago, the prevalent view in psychology was that although learning and the formation of new memories are lifelong occurrences, the neural changes associated with these events were all in the existing receptors. No new neural hardware, from synapses to neurons, was thought to appear after a protracted period early in life. In the past 20 years, another view has supplanted this one, showing that although the juvenile period is especially suited to neuroplastic adaptation, there is hard neuroplastic change later in life as well. We review a selection of evidence for this view from both animal and human models, showing how it reflects three principles of neuroplasticity: 1) earlier and later experience-induced changes to neuroarchitecture differ in degree more so than in type; 2) the types of experiences that lead to neuroplastic change narrow with age; and 3) differences in the amenability of neural circuitry to change result from basic differences in neuroarchitecture and neuroenvironment in different phases of development.
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209
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Making sense of gray matter abnormalities in chronic orofacial pain--synthesizing divergent findings. J Neurosci 2011; 31:12396-7. [PMID: 21880900 DOI: 10.1523/jneurosci.3103-11.2011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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210
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Taubert M, Villringer A, Ragert P. Learning-related gray and white matter changes in humans: an update. Neuroscientist 2011; 18:320-5. [PMID: 22013150 DOI: 10.1177/1073858411419048] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In contrast to a long-held view that structural brain plasticity is restricted to critical periods during ontogenesis, it is now well established that the adult human brain preserves its capacity for functional and structural changes throughout life. Although early experimental studies were mainly performed in animals, technical developments especially in the field of MRI enabled the non-invasive observation of functional and structural reorganization in the human brain. This article reports recent insights in human brain plasticity with particular emphasis on (dynamic) learning-related structural gray and white matter changes and its behavioral correlates.
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Affiliation(s)
- Marco Taubert
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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211
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One week of motor adaptation induces structural changes in primary motor cortex that predict long-term memory one year later. J Neurosci 2011; 31:11808-13. [PMID: 21849541 DOI: 10.1523/jneurosci.2253-11.2011] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The neural bases of motor adaptation have been extensively explored in human and nonhuman primates. A network including the cerebellum, primary motor cortex, and posterior parietal cortex appears to be crucial for this type of learning. Yet, to date, it is unclear whether these regions contribute directly or indirectly to the formation of motor memories. Here we trained subjects on a complex visuomotor rotation associated with long-term memory (in the order of months) to identify potential sites of structural plasticity induced by adaptation. One week of training led to (1) an increment in local gray matter concentration over the hand area of the contralateral primary motor cortex and (2) an increase in fractional anisotropy in an area underneath this region that correlated with the speed of learning. Moreover, the change in gray matter concentration measured immediately after training predicted improvements in the speed of learning during readaptation 1 year later. Our study suggests that motor adaptation induces structural plasticity in primary motor circuits. In addition, it provides the first piece of evidence indicating that early structural changes induced by motor learning may impact on behavior up to 1 year after training.
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212
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Nieman BJ, Wong MD, Henkelman RM. Genes into geometry: imaging for mouse development in 3D. Curr Opin Genet Dev 2011; 21:638-46. [PMID: 21907568 DOI: 10.1016/j.gde.2011.08.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 08/19/2011] [Accepted: 08/23/2011] [Indexed: 02/07/2023]
Abstract
Mammalian development is a sophisticated program coordinated by a complex set of genetic and physiological factors. Alterations in anatomy or morphology provide intrinsic measures of progress in or deviations from this program. Emerging three-dimensional imaging methods now allow for more sophisticated morphological assessment than ever before, enabling comprehensive phenotyping, visualization of anatomical context and patterns, automated and quantitative morphological analysis, as well as improved understanding of the developmental time course. Furthermore, these imaging tools are becoming increasingly available and will consequently play a prominent role in elucidating the factors that direct and influence mammalian development.
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Affiliation(s)
- Brian J Nieman
- Mouse Imaging Centre, Hospital for Sick Children, and Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
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213
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Caudate nucleus-dependent response strategies in a virtual navigation task are associated with lower basal cortisol and impaired episodic memory. Neurobiol Learn Mem 2011; 96:173-80. [DOI: 10.1016/j.nlm.2011.04.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 02/18/2011] [Accepted: 04/08/2011] [Indexed: 11/21/2022]
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214
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Ellegood J, Lerch JP, Henkelman RM. Brain abnormalities in a Neuroligin3 R451C knockin mouse model associated with autism. Autism Res 2011; 4:368-76. [PMID: 21882360 DOI: 10.1002/aur.215] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Magnetic resonance imaging (MRI) has been used quite extensively for examining morphological changes in human and animal brains. One of the many advantages to examining mouse models of human autism is that we are able to examine single gene targets, like that of Neuroligin3 R451C knockin (NL3 KI), which has been directly implicated in human autism. The NL3 KI mouse model has marked volume differences in many different structures in the brain: gray matter structures, such as the hippocampus, the striatum, and the thalamus, were all found to be smaller in the NL3 KI. Further, many white matter structures were found to be significantly smaller, such as the cerebral peduncle, corpus callosum, fornix/fimbria, and internal capsule. Fractional anisotropy measurements in these structures were also measured, and no differences were found. The volume changes in the white matter regions, therefore, are not due to a general breakdown in the microstructure of the tissue and seem to be caused by fewer axons or less mature axons. A larger radial diffusivity was also found in localized regions of the corpus callosum and cerebellum. The corpus callosal changes are particularly interesting as the thinning (or reduced volume) of the corpus callosum is a consistent finding in autism. This suggests that the NL3 KI model may be useful for examining white matter changes associated with autism.
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Affiliation(s)
- Jacob Ellegood
- Mouse Imaging Centre (MICe), Hospital for Sick Children, Toronto, Ontario, Canada.
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215
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Akers KG, Kushner SA, Leslie AT, Clarke L, van der Kooy D, Lerch JP, Frankland PW. Fetal alcohol exposure leads to abnormal olfactory bulb development and impaired odor discrimination in adult mice. Mol Brain 2011; 4:29. [PMID: 21736737 PMCID: PMC3148973 DOI: 10.1186/1756-6606-4-29] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/07/2011] [Indexed: 01/12/2023] Open
Abstract
Background Children whose mothers consumed alcohol during pregnancy exhibit widespread brain abnormalities and a complex array of behavioral disturbances. Here, we used a mouse model of fetal alcohol exposure to investigate relationships between brain abnormalities and specific behavioral alterations during adulthood. Results Mice drank a 10% ethanol solution throughout pregnancy. When fetal alcohol-exposed offspring reached adulthood, we used high resolution MRI to conduct a brain-wide screen for structural changes and found that the largest reduction in volume occurred in the olfactory bulbs. Next, we tested adult mice in an associative olfactory task and found that fetal alcohol exposure impaired discrimination between similar odors but left odor memory intact. Finally, we investigated olfactory bulb neurogenesis as a potential mechanism by performing an in vitro neurosphere assay, in vivo labeling of new cells using BrdU, and in vivo labeling of new cells using a transgenic reporter system. We found that fetal alcohol exposure decreased the number of neural precursor cells in the subependymal zone and the number of new cells in the olfactory bulbs during the first few postnatal weeks. Conclusions Using a combination of techniques, including structural brain imaging, in vitro and in vivo cell detection methods, and behavioral testing, we found that fetal alcohol exposure results in smaller olfactory bulbs and impairments in odor discrimination that persist into adulthood. Furthermore, we found that these abnormalities in olfactory bulb structure and function may arise from deficits in the generation of new olfactory bulb neurons during early postnatal development.
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Affiliation(s)
- Katherine G Akers
- Neurosciences and Mental Health, Hospital for Sick Children, and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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216
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Taubert M, Lohmann G, Margulies DS, Villringer A, Ragert P. Long-term effects of motor training on resting-state networks and underlying brain structure. Neuroimage 2011; 57:1492-8. [PMID: 21672633 DOI: 10.1016/j.neuroimage.2011.05.078] [Citation(s) in RCA: 207] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 05/27/2011] [Accepted: 05/28/2011] [Indexed: 02/08/2023] Open
Abstract
Acquired motor skills are coded in fronto-parietal brain networks, but how these networks evolve through motor training is unclear. On the one hand, increased functional connectivity has been shown immediately after a training session; on the other hand, training-induced structural changes are visible only after several weeks. Based on known associations between functional and structural network development during human ontogeny, we hypothesised that learning a challenging motor task leads to long-lasting changes in functional resting-state networks and the corresponding cortical and sub-cortical brain structures. Using longitudinal functional and structural MRI at multiple time points, we demonstrate increased fronto-parietal network connectivity one week after two brief motor training sessions in a dynamic balancing task, although subjects were engaged in their regular daily activities during the week. Repeated training sessions over six consecutive weeks progressively modulate these changes in accordance with individual performance improvements. Multimodal correlation analyses showed an association between structural grey matter alterations and functional connectivity changes in prefrontal and supplementary-motor areas. These coincident changes were most prominent in the first three weeks of training. In contrast, changes in fronto-parietal functional connectivity and the underlying white matter fibre structure developed gradually during the six weeks. Our results demonstrate a tight correlation between training-induced functional and structural brain plasticity on the systems level and suggest a functional relevance of intrinsic brain activity for morphological adaptation in the human brain.
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Affiliation(s)
- Marco Taubert
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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