Qinlin Yu, Yun Peng, Huiying Kang, Qinmu Peng, M. Ouyang, Michelle Slinger, D. Hu, H. Shou, Fang Fang, Hao Huang
Abstract Comprehensive delineation of white matter (WM) microstructural maturation from birth to childhood is critical for understanding spatiotemporally differential circuit formation. Without a relatively large sample of datasets and coverage of critical developmental periods of both infancy and early childhood, differential maturational charts across WM tracts cannot be delineated. With diffusion tensor imaging (DTI) of 118 typically developing (TD) children aged 0–8 years and 31 children with autistic spectrum disorder (ASD) aged 2–7 years, the microstructure of every major WM tract and tract group was measured with DTI metrics to delineate differential WM maturation. The exponential model of microstructural maturation of all WM was identified. The WM developmental curves were separated into fast, intermediate, and slow phases in 0–8 years with distinctive time period of each phase across the tracts. Shorter periods of the fast and intermediate phases in certain tracts, such as the commissural tracts, indicated faster earlier development. With TD WM maturational curves as the reference, higher residual variance of WM microstructure was found in children with ASD. The presented comprehensive and differential charts of TD WM microstructural maturation of all major tracts and tract groups in 0–8 years provide reference standards for biomarker detection of neuropsychiatric disorders.
{"title":"Differential White Matter Maturation from Birth to 8 Years of Age","authors":"Qinlin Yu, Yun Peng, Huiying Kang, Qinmu Peng, M. Ouyang, Michelle Slinger, D. Hu, H. Shou, Fang Fang, Hao Huang","doi":"10.1093/cercor/bhz268","DOIUrl":"https://doi.org/10.1093/cercor/bhz268","url":null,"abstract":"Abstract Comprehensive delineation of white matter (WM) microstructural maturation from birth to childhood is critical for understanding spatiotemporally differential circuit formation. Without a relatively large sample of datasets and coverage of critical developmental periods of both infancy and early childhood, differential maturational charts across WM tracts cannot be delineated. With diffusion tensor imaging (DTI) of 118 typically developing (TD) children aged 0–8 years and 31 children with autistic spectrum disorder (ASD) aged 2–7 years, the microstructure of every major WM tract and tract group was measured with DTI metrics to delineate differential WM maturation. The exponential model of microstructural maturation of all WM was identified. The WM developmental curves were separated into fast, intermediate, and slow phases in 0–8 years with distinctive time period of each phase across the tracts. Shorter periods of the fast and intermediate phases in certain tracts, such as the commissural tracts, indicated faster earlier development. With TD WM maturational curves as the reference, higher residual variance of WM microstructure was found in children with ASD. The presented comprehensive and differential charts of TD WM microstructural maturation of all major tracts and tract groups in 0–8 years provide reference standards for biomarker detection of neuropsychiatric disorders.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"61 1","pages":"2674 - 2690"},"PeriodicalIF":0.0,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83681849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mandy H. Paul, M. Choi, J. Schlaudraff, T. Deller, D. Del Turco
Abstract The plasticity-related protein Synaptopodin (SP) has been implicated in neuronal plasticity. SP is targeted to dendritic spines and the axon initial segment, where it organizes the endoplasmic reticulum (ER) into the spine apparatus and the cisternal organelle, respectively. Here, we report an inducible third localization of SP in the somata of activated granule cell ensembles in mouse dentate gyrus. Using immunofluorescence and fluorescence in situ hybridization, we observed a subpopulation of mature granule cells (~1–2%) exhibiting perinuclear SP protein and a strong somatic SP mRNA signal. Double immunofluorescence labeling for Arc demonstrated that ~ 75% of these somatic SP-positive cells are also Arc-positive. Placement of mice into a novel environment caused a rapid (~2–4 h) induction of Arc, SP mRNA, and SP protein in exploration-induced granule cell ensembles. Lesion experiments showed that this induction requires input from the entorhinal cortex. Somatic SP colocalized with α-Actinin2, a known binding partner of SP. Finally, ultrastructural analysis revealed SP immunoprecipitate on dense plates linking cytoplasmic and perinuclear ER cisterns; these structures were absent in granule cells of SP-deficient mice. Our data implicate SP in the formation of contextual representations in the dentate gyrus and the behaviorally induced reorganization of cytoplasmic and perinuclear ER.
{"title":"Granule Cell Ensembles in Mouse Dentate Gyrus Rapidly Upregulate the Plasticity-Related Protein Synaptopodin after Exploration Behavior","authors":"Mandy H. Paul, M. Choi, J. Schlaudraff, T. Deller, D. Del Turco","doi":"10.1093/cercor/bhz231","DOIUrl":"https://doi.org/10.1093/cercor/bhz231","url":null,"abstract":"Abstract The plasticity-related protein Synaptopodin (SP) has been implicated in neuronal plasticity. SP is targeted to dendritic spines and the axon initial segment, where it organizes the endoplasmic reticulum (ER) into the spine apparatus and the cisternal organelle, respectively. Here, we report an inducible third localization of SP in the somata of activated granule cell ensembles in mouse dentate gyrus. Using immunofluorescence and fluorescence in situ hybridization, we observed a subpopulation of mature granule cells (~1–2%) exhibiting perinuclear SP protein and a strong somatic SP mRNA signal. Double immunofluorescence labeling for Arc demonstrated that ~ 75% of these somatic SP-positive cells are also Arc-positive. Placement of mice into a novel environment caused a rapid (~2–4 h) induction of Arc, SP mRNA, and SP protein in exploration-induced granule cell ensembles. Lesion experiments showed that this induction requires input from the entorhinal cortex. Somatic SP colocalized with α-Actinin2, a known binding partner of SP. Finally, ultrastructural analysis revealed SP immunoprecipitate on dense plates linking cytoplasmic and perinuclear ER cisterns; these structures were absent in granule cells of SP-deficient mice. Our data implicate SP in the formation of contextual representations in the dentate gyrus and the behaviorally induced reorganization of cytoplasmic and perinuclear ER.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"9 1","pages":"2185 - 2198"},"PeriodicalIF":0.0,"publicationDate":"2019-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75234167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Vezzoli, C. Calì, M. De Roo, L. Ponzoni, E. Sogne, N. Gagnon, M. Francolini, D. Braida, M. Sala, D. Muller, A. Falqui, P. Magistretti
Abstract Long-term memory formation (LTM) is a process accompanied by energy-demanding structural changes at synapses and increased spine density. Concomitant increases in both spine volume and postsynaptic density (PSD) surface area have been suggested but never quantified in vivo by clear-cut experimental evidence. Using novel object recognition in mice as a learning task followed by 3D electron microscopy analysis, we demonstrate that LTM induced all aforementioned synaptic changes, together with an increase in the size of astrocytic glycogen granules, which are a source of lactate for neurons. The selective inhibition of glycogen metabolism in astrocytes impaired learning, affecting all the related synaptic changes. Intrahippocampal administration of l-lactate rescued the behavioral phenotype, along with spine density within 24 hours. Spine dynamics in hippocampal organotypic slices undergoing theta burst-induced long-term potentiation was similarly affected by inhibition of glycogen metabolism and rescued by l-lactate. These results suggest that learning primes astrocytic energy stores and signaling to sustain synaptic plasticity via l-lactate.
{"title":"Ultrastructural Evidence for a Role of Astrocytes and Glycogen-Derived Lactate in Learning-Dependent Synaptic Stabilization","authors":"E. Vezzoli, C. Calì, M. De Roo, L. Ponzoni, E. Sogne, N. Gagnon, M. Francolini, D. Braida, M. Sala, D. Muller, A. Falqui, P. Magistretti","doi":"10.1093/cercor/bhz226","DOIUrl":"https://doi.org/10.1093/cercor/bhz226","url":null,"abstract":"Abstract Long-term memory formation (LTM) is a process accompanied by energy-demanding structural changes at synapses and increased spine density. Concomitant increases in both spine volume and postsynaptic density (PSD) surface area have been suggested but never quantified in vivo by clear-cut experimental evidence. Using novel object recognition in mice as a learning task followed by 3D electron microscopy analysis, we demonstrate that LTM induced all aforementioned synaptic changes, together with an increase in the size of astrocytic glycogen granules, which are a source of lactate for neurons. The selective inhibition of glycogen metabolism in astrocytes impaired learning, affecting all the related synaptic changes. Intrahippocampal administration of l-lactate rescued the behavioral phenotype, along with spine density within 24 hours. Spine dynamics in hippocampal organotypic slices undergoing theta burst-induced long-term potentiation was similarly affected by inhibition of glycogen metabolism and rescued by l-lactate. These results suggest that learning primes astrocytic energy stores and signaling to sustain synaptic plasticity via l-lactate.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"15 3 1","pages":"2114 - 2127"},"PeriodicalIF":0.0,"publicationDate":"2019-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77374903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ‘default network’ (DN) becomes active when the mind is steered internally towards self-generated thoughts but turns dormant when the mind is directed externally towards the outside world. While hypotheses have been proposed to characterise the association and dissociation between different component areas of the DN, it remains unclear how they coalesce into a unitary network and fractionate into different sub-networks. Here we identified two distinct subsystems within the DN – while both subsystems show common disinterest in externally-oriented visuospatial tasks, their functional profiles differ strikingly according to the preferred contents of thoughts, preferred modes of task requirement, and causative neural dynamics among network nodes. Specifically, one subsystem comprises key nodes of the frontotemporal semantic regions. This network shows moderate dislike to visuospatial tasks, shows proclivity for task-contexts with restraints on thoughts and responses, and prefers thoughts that are focused on other people. By contrast, the other subsystem comprises the cortical midline structure and angular gyri. This network shows strong aversion to visuospatial tasks, favours task-contexts allowing free self-generated thoughts without constraints, and prefers thoughts that are focused on self. Furthermore, causative connectivity reveals that task-contexts systematically alter the dynamics within and between subsystems, suggesting flexible adaption to situational demands. This ‘self/inward vs. others/outward’ separation within the broad DN resembles recent discoveries regarding a dyadic structure within the frontoparietal network that comprises regions controlling memories/thoughts vs. regions controlling sensory-motoric processes, and echoes burgeoning views that the brain is organised with a spectrum-like architecture along gradational changes of ‘inward vs. outward’ preferences. Significance Rather than construing the default network (DN) as ‘task-negative’ regions that passively react to off-task mind-wandering, researchers have begun to acknowledge the active role of the DN in supporting internally-directed cognition. Here we found a striking dichotomy within the DN in terms of the subsystems’ task-driven functional and connectivity profiles, extending beyond previous inferences using meta-analysis and resting-state fMRI. This dichotomy reflects a local manifestation of a macro-scale gradient representation spanning across the broad cerebral cortex. This cortical gradient increases its representational complexity, from primitive sensory and motoric processing, through lexical-semantic codes for language tasks, to abstract self-generated thoughts in task-free contexts. These findings enable a framework where the separate yet related literatures of semantic cognition and default-mode processes converge.
{"title":"Bipartite Functional Fractionation within the Default Network Supports Disparate Forms of Internally Oriented Cognition","authors":"R. Chiou, Gina F. Humphreys, M. L. Lambon Ralph","doi":"10.1101/864603","DOIUrl":"https://doi.org/10.1101/864603","url":null,"abstract":"The ‘default network’ (DN) becomes active when the mind is steered internally towards self-generated thoughts but turns dormant when the mind is directed externally towards the outside world. While hypotheses have been proposed to characterise the association and dissociation between different component areas of the DN, it remains unclear how they coalesce into a unitary network and fractionate into different sub-networks. Here we identified two distinct subsystems within the DN – while both subsystems show common disinterest in externally-oriented visuospatial tasks, their functional profiles differ strikingly according to the preferred contents of thoughts, preferred modes of task requirement, and causative neural dynamics among network nodes. Specifically, one subsystem comprises key nodes of the frontotemporal semantic regions. This network shows moderate dislike to visuospatial tasks, shows proclivity for task-contexts with restraints on thoughts and responses, and prefers thoughts that are focused on other people. By contrast, the other subsystem comprises the cortical midline structure and angular gyri. This network shows strong aversion to visuospatial tasks, favours task-contexts allowing free self-generated thoughts without constraints, and prefers thoughts that are focused on self. Furthermore, causative connectivity reveals that task-contexts systematically alter the dynamics within and between subsystems, suggesting flexible adaption to situational demands. This ‘self/inward vs. others/outward’ separation within the broad DN resembles recent discoveries regarding a dyadic structure within the frontoparietal network that comprises regions controlling memories/thoughts vs. regions controlling sensory-motoric processes, and echoes burgeoning views that the brain is organised with a spectrum-like architecture along gradational changes of ‘inward vs. outward’ preferences. Significance Rather than construing the default network (DN) as ‘task-negative’ regions that passively react to off-task mind-wandering, researchers have begun to acknowledge the active role of the DN in supporting internally-directed cognition. Here we found a striking dichotomy within the DN in terms of the subsystems’ task-driven functional and connectivity profiles, extending beyond previous inferences using meta-analysis and resting-state fMRI. This dichotomy reflects a local manifestation of a macro-scale gradient representation spanning across the broad cerebral cortex. This cortical gradient increases its representational complexity, from primitive sensory and motoric processing, through lexical-semantic codes for language tasks, to abstract self-generated thoughts in task-free contexts. These findings enable a framework where the separate yet related literatures of semantic cognition and default-mode processes converge.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"123 1","pages":"5484 - 5501"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83345805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Bhumika, Mari Nakamura, Patrícia Valério, Magdalena Sołyga, Henrik Lindén, T. R. Barkat
Abstract Neuronal circuits are shaped by experience during time windows of increased plasticity in postnatal development. In the auditory system, the critical period for the simplest sounds—pure frequency tones—is well defined. Critical periods for more complex sounds remain to be elucidated. We used in vivo electrophysiological recordings in the mouse auditory cortex to demonstrate that passive exposure to frequency modulated sweeps (FMS) from postnatal day 31 to 38 leads to long-term changes in the temporal representation of sweep directions. Immunohistochemical analysis revealed a decreased percentage of layer 4 parvalbumin-positive (PV+) cells during this critical period, paralleled with a transient increase in responses to FMS, but not to pure tones. Preventing the PV+ cell decrease with continuous white noise exposure delayed the critical period onset, suggesting a reduction in inhibition as a mechanism for this plasticity. Our findings shed new light on the dependence of plastic windows on stimulus complexity that persistently sculpt the functional organization of the auditory cortex.
{"title":"A Late Critical Period for Frequency Modulated Sweeps in the Mouse Auditory System","authors":"S. Bhumika, Mari Nakamura, Patrícia Valério, Magdalena Sołyga, Henrik Lindén, T. R. Barkat","doi":"10.1093/cercor/bhz262","DOIUrl":"https://doi.org/10.1093/cercor/bhz262","url":null,"abstract":"Abstract Neuronal circuits are shaped by experience during time windows of increased plasticity in postnatal development. In the auditory system, the critical period for the simplest sounds—pure frequency tones—is well defined. Critical periods for more complex sounds remain to be elucidated. We used in vivo electrophysiological recordings in the mouse auditory cortex to demonstrate that passive exposure to frequency modulated sweeps (FMS) from postnatal day 31 to 38 leads to long-term changes in the temporal representation of sweep directions. Immunohistochemical analysis revealed a decreased percentage of layer 4 parvalbumin-positive (PV+) cells during this critical period, paralleled with a transient increase in responses to FMS, but not to pure tones. Preventing the PV+ cell decrease with continuous white noise exposure delayed the critical period onset, suggesting a reduction in inhibition as a mechanism for this plasticity. Our findings shed new light on the dependence of plastic windows on stimulus complexity that persistently sculpt the functional organization of the auditory cortex.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"34 1","pages":"2586 - 2599"},"PeriodicalIF":0.0,"publicationDate":"2019-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83094182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. H. Lindström, S. Sundberg, M. Larsson, F. K. Andersson, J. Broman, Björn Granseth
Abstract The most common excitatory neurotransmitter in the central nervous system, glutamate, is loaded into synaptic vesicles by vesicular glutamate transporters (VGluTs). The primary isoforms, VGluT1 and 2, are expressed in complementary patterns throughout the brain and correlate with short-term synaptic plasticity. VGluT1 deficiency is observed in certain neurological disorders, and hemizygous (VGluT1+/−) mice display increased anxiety and depression, altered sensorimotor gating, and impairments in learning and memory. The synaptic mechanisms underlying these behavioral deficits are unknown. Here, we show that VGluT1+/− mice had decreased visual processing speeds during a sustained visual-spatial attention task. Furthermore, in vitro recordings of corticothalamic (CT) synapses revealed dramatic reductions in short-term facilitation, increased initial release probability, and earlier synaptic depression in VGluT1+/− mice. Our electron microscopy results show that VGluT1 concentration is reduced at CT synapses of hemizygous mice, but other features (such as vesicle number and active zone size) are unchanged. We conclude that VGluT1-haploinsuficiency decreases the dynamic range of gain modulation provided by CT feedback to the thalamus, and this deficiency contributes to the observed attentional processing deficit. We further hypothesize that VGluT1 concentration regulates release probability by applying a “brake” to an unidentified presynaptic protein that typically acts as a positive regulator of release.
{"title":"VGluT1 Deficiency Impairs Visual Attention and Reduces the Dynamic Range of Short-Term Plasticity at Corticothalamic Synapses","authors":"S. H. Lindström, S. Sundberg, M. Larsson, F. K. Andersson, J. Broman, Björn Granseth","doi":"10.1093/cercor/bhz204","DOIUrl":"https://doi.org/10.1093/cercor/bhz204","url":null,"abstract":"Abstract The most common excitatory neurotransmitter in the central nervous system, glutamate, is loaded into synaptic vesicles by vesicular glutamate transporters (VGluTs). The primary isoforms, VGluT1 and 2, are expressed in complementary patterns throughout the brain and correlate with short-term synaptic plasticity. VGluT1 deficiency is observed in certain neurological disorders, and hemizygous (VGluT1+/−) mice display increased anxiety and depression, altered sensorimotor gating, and impairments in learning and memory. The synaptic mechanisms underlying these behavioral deficits are unknown. Here, we show that VGluT1+/− mice had decreased visual processing speeds during a sustained visual-spatial attention task. Furthermore, in vitro recordings of corticothalamic (CT) synapses revealed dramatic reductions in short-term facilitation, increased initial release probability, and earlier synaptic depression in VGluT1+/− mice. Our electron microscopy results show that VGluT1 concentration is reduced at CT synapses of hemizygous mice, but other features (such as vesicle number and active zone size) are unchanged. We conclude that VGluT1-haploinsuficiency decreases the dynamic range of gain modulation provided by CT feedback to the thalamus, and this deficiency contributes to the observed attentional processing deficit. We further hypothesize that VGluT1 concentration regulates release probability by applying a “brake” to an unidentified presynaptic protein that typically acts as a positive regulator of release.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"12 1","pages":"1813 - 1829"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84257624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Brinkhuis, Á. Kristjánsson, B. Harvey, J. Brascamp
Abstract Priming of attention shifts involves the reduction in search RTs that occurs when target location or target features repeat. We used functional magnetic resonance imaging to investigate the neural basis of such attentional priming, specifically focusing on its temporal characteristics over trial sequences. We first replicated earlier findings by showing that repetition of target color and of target location from the immediately preceding trial both result in reduced blood oxygen level-dependent (BOLD) signals in a cortical network that encompasses occipital, parietal, and frontal cortices: lag-1 repetition suppression. While such lag-1 suppression can have a number of explanations, behaviorally, the influence of attentional priming extends further, with the influence of past search trials gradually decaying across multiple subsequent trials. Our results reveal that the same regions within the frontoparietal network that show lag-1 suppression, also show longer term BOLD reductions that diminish over the course of several trial presentations, keeping pace with the decaying behavioral influence of past target properties across trials. This distinct parallel between the across-trial patterns of cortical BOLD and search RT reductions, provides strong evidence that these cortical areas play a key role in attentional priming.
{"title":"Temporal Characteristics of Priming of Attention Shifts Are Mirrored by BOLD Response Patterns in the Frontoparietal Attention Network","authors":"M. Brinkhuis, Á. Kristjánsson, B. Harvey, J. Brascamp","doi":"10.1093/cercor/bhz238","DOIUrl":"https://doi.org/10.1093/cercor/bhz238","url":null,"abstract":"Abstract Priming of attention shifts involves the reduction in search RTs that occurs when target location or target features repeat. We used functional magnetic resonance imaging to investigate the neural basis of such attentional priming, specifically focusing on its temporal characteristics over trial sequences. We first replicated earlier findings by showing that repetition of target color and of target location from the immediately preceding trial both result in reduced blood oxygen level-dependent (BOLD) signals in a cortical network that encompasses occipital, parietal, and frontal cortices: lag-1 repetition suppression. While such lag-1 suppression can have a number of explanations, behaviorally, the influence of attentional priming extends further, with the influence of past search trials gradually decaying across multiple subsequent trials. Our results reveal that the same regions within the frontoparietal network that show lag-1 suppression, also show longer term BOLD reductions that diminish over the course of several trial presentations, keeping pace with the decaying behavioral influence of past target properties across trials. This distinct parallel between the across-trial patterns of cortical BOLD and search RT reductions, provides strong evidence that these cortical areas play a key role in attentional priming.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"43 1","pages":"2267 - 2280"},"PeriodicalIF":0.0,"publicationDate":"2019-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77409591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Turégano-Lopez, A. Santuy, J. DeFelipe, Á. Merchán-Pérez
Abstract Multivesicular bodies (MVBs) are membrane-bound organelles that belong to the endosomal pathway. They participate in the transport, sorting, storage, recycling, degradation, and release of multiple substances. They interchange cargo with other organelles and participate in their renovation and degradation. We have used focused ion beam milling and scanning electron microscopy (FIB-SEM) to obtain stacks of serial sections from the neuropil of the somatosensory cortex of the juvenile rat. Using dedicated software, we have 3D-reconstructed 1618 MVBs. The mean density of MVBs was 0.21 per cubic micron. They were unequally distributed between dendrites (39.14%), axons (18.16%), and nonsynaptic cell processes (42.70%). About one out of five MVBs (18.16%) were docked on mitochondria, representing the process by which the endosomal pathway participates in mitochondrial maintenance. Other features of MVBs, such as the presence of tubular protrusions (6.66%) or clathrin coats (19.74%) can also be interpreted in functional terms, since both are typical of early endosomes. The sizes of MVBs follow a lognormal distribution, with differences across cortical layers and cellular compartments. The mean volume of dendritic MVBs is more than twice as large as the volume of axonic MVBs. In layer I, they are smaller, on average, than in the other layers.
{"title":"Size, Shape, and Distribution of Multivesicular Bodies in the Juvenile Rat Somatosensory Cortex: A 3D Electron Microscopy Study","authors":"M. Turégano-Lopez, A. Santuy, J. DeFelipe, Á. Merchán-Pérez","doi":"10.1093/cercor/bhz211","DOIUrl":"https://doi.org/10.1093/cercor/bhz211","url":null,"abstract":"Abstract Multivesicular bodies (MVBs) are membrane-bound organelles that belong to the endosomal pathway. They participate in the transport, sorting, storage, recycling, degradation, and release of multiple substances. They interchange cargo with other organelles and participate in their renovation and degradation. We have used focused ion beam milling and scanning electron microscopy (FIB-SEM) to obtain stacks of serial sections from the neuropil of the somatosensory cortex of the juvenile rat. Using dedicated software, we have 3D-reconstructed 1618 MVBs. The mean density of MVBs was 0.21 per cubic micron. They were unequally distributed between dendrites (39.14%), axons (18.16%), and nonsynaptic cell processes (42.70%). About one out of five MVBs (18.16%) were docked on mitochondria, representing the process by which the endosomal pathway participates in mitochondrial maintenance. Other features of MVBs, such as the presence of tubular protrusions (6.66%) or clathrin coats (19.74%) can also be interpreted in functional terms, since both are typical of early endosomes. The sizes of MVBs follow a lognormal distribution, with differences across cortical layers and cellular compartments. The mean volume of dendritic MVBs is more than twice as large as the volume of axonic MVBs. In layer I, they are smaller, on average, than in the other layers.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"3 1","pages":"1887 - 1901"},"PeriodicalIF":0.0,"publicationDate":"2019-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87416418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The development of executive function is linked to maturation of prefrontal cortex (PFC) in childhood. Childhood obesity has been associated with changes in brain structure, particularly in PFC, as well as deficits in executive functions. We aimed to determine whether differences in cortical structure mediate the relationship between executive function and childhood obesity. We analyzed MR-derived measures of cortical thickness for 2700 children between the ages of 9 and 11 years, recruited as part of the NIH Adolescent Brain and Cognitive Development (ABCD) study. We related our findings to measures of executive function and body mass index (BMI). In our analysis, increased BMI was associated with significantly reduced mean cortical thickness, as well as specific bilateral reduced cortical thickness in prefrontal cortical regions. This relationship remained after accounting for age, sex, race, parental education, household income, birth-weight, and in-scanner motion. Increased BMI was also associated with lower executive function. Reduced thickness in the rostral medial and superior frontal cortex, the inferior frontal gyrus, and the lateral orbitofrontal cortex partially accounted for reductions in executive function. These results suggest that childhood obesity is associated with compromised executive function. This relationship may be partly explained by BMI-associated reduced cortical thickness in the PFC.
{"title":"Childhood Obesity, Cortical Structure, and Executive Function in Healthy Children","authors":"L. Ronan, A. Alexander-Bloch, P. Fletcher","doi":"10.1093/cercor/bhz257","DOIUrl":"https://doi.org/10.1093/cercor/bhz257","url":null,"abstract":"Abstract The development of executive function is linked to maturation of prefrontal cortex (PFC) in childhood. Childhood obesity has been associated with changes in brain structure, particularly in PFC, as well as deficits in executive functions. We aimed to determine whether differences in cortical structure mediate the relationship between executive function and childhood obesity. We analyzed MR-derived measures of cortical thickness for 2700 children between the ages of 9 and 11 years, recruited as part of the NIH Adolescent Brain and Cognitive Development (ABCD) study. We related our findings to measures of executive function and body mass index (BMI). In our analysis, increased BMI was associated with significantly reduced mean cortical thickness, as well as specific bilateral reduced cortical thickness in prefrontal cortical regions. This relationship remained after accounting for age, sex, race, parental education, household income, birth-weight, and in-scanner motion. Increased BMI was also associated with lower executive function. Reduced thickness in the rostral medial and superior frontal cortex, the inferior frontal gyrus, and the lateral orbitofrontal cortex partially accounted for reductions in executive function. These results suggest that childhood obesity is associated with compromised executive function. This relationship may be partly explained by BMI-associated reduced cortical thickness in the PFC.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"46 1","pages":"2519 - 2528"},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76247225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Timo Saarinen, J. Kujala, H. Laaksonen, A. Jalava, R. Salmelin
Abstract Both motor and cognitive aspects of behavior depend on dynamic, accurately timed neural processes in large-scale brain networks. Here, we studied synchronous interplay between cortical regions during production of cognitive-motor sequences in humans. Specifically, variants of handwriting that differed in motor variability, linguistic content, and memorization of movement cues were contrasted to unveil functional sensitivity of corticocortical connections. Data-driven magnetoencephalography mapping (n = 10) uncovered modulation of mostly left-hemispheric corticocortical interactions, as quantified by relative changes in phase synchronization. At low frequencies (~2–13 Hz), enhanced frontoparietal synchrony was related to regular handwriting, whereas premotor cortical regions synchronized for simple loop production and temporo-occipital areas for a writing task substituting normal script with loop patterns. At the beta-to-gamma band (~13–45 Hz), enhanced synchrony was observed for regular handwriting in the central and frontoparietal regions, including connections between the sensorimotor and supplementary motor cortices and between the parietal and dorsal premotor/precentral cortices. Interpreted within a modular framework, these modulations of synchrony mainly highlighted interactions of the putative pericentral subsystem of hand coordination and the frontoparietal subsystem mediating working memory operations. As part of cortical dynamics, interregional phase synchrony varies depending on task demands in production of cognitive-motor sequences.
{"title":"Task-Modulated Corticocortical Synchrony in the Cognitive-Motor Network Supporting Handwriting","authors":"Timo Saarinen, J. Kujala, H. Laaksonen, A. Jalava, R. Salmelin","doi":"10.1093/cercor/bhz210","DOIUrl":"https://doi.org/10.1093/cercor/bhz210","url":null,"abstract":"Abstract Both motor and cognitive aspects of behavior depend on dynamic, accurately timed neural processes in large-scale brain networks. Here, we studied synchronous interplay between cortical regions during production of cognitive-motor sequences in humans. Specifically, variants of handwriting that differed in motor variability, linguistic content, and memorization of movement cues were contrasted to unveil functional sensitivity of corticocortical connections. Data-driven magnetoencephalography mapping (n = 10) uncovered modulation of mostly left-hemispheric corticocortical interactions, as quantified by relative changes in phase synchronization. At low frequencies (~2–13 Hz), enhanced frontoparietal synchrony was related to regular handwriting, whereas premotor cortical regions synchronized for simple loop production and temporo-occipital areas for a writing task substituting normal script with loop patterns. At the beta-to-gamma band (~13–45 Hz), enhanced synchrony was observed for regular handwriting in the central and frontoparietal regions, including connections between the sensorimotor and supplementary motor cortices and between the parietal and dorsal premotor/precentral cortices. Interpreted within a modular framework, these modulations of synchrony mainly highlighted interactions of the putative pericentral subsystem of hand coordination and the frontoparietal subsystem mediating working memory operations. As part of cortical dynamics, interregional phase synchrony varies depending on task demands in production of cognitive-motor sequences.","PeriodicalId":9825,"journal":{"name":"Cerebral Cortex (New York, NY)","volume":"93 1","pages":"1871 - 1886"},"PeriodicalIF":0.0,"publicationDate":"2019-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87663240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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