scholarly journals Concerted and mosaic evolution of functional modules in songbird brains

2017 ◽  
Vol 284 (1854) ◽  
pp. 20170469 ◽  
Author(s):  
Jordan M. Moore ◽  
Timothy J. DeVoogd
Keyword(s):  
Size Composition ◽  
Brain Structures ◽  
Major Elements ◽  
Neural Systems ◽  
Brain Areas ◽  
Functional Capabilities ◽  
Developmental Mechanisms ◽  
Mosaic Model ◽  
Residual Variation ◽  
Functional Capacities

Vertebrate brains differ in overall size, composition and functional capacities, but the evolutionary processes linking these traits are unclear. Two leading models offer opposing views: the concerted model ascribes major dimensions of covariation in brain structures to developmental events, whereas the mosaic model relates divergent structures to functional capabilities. The models are often cast as incompatible, but they must be unified to explain how adaptive changes in brain structure arise from pre-existing architectures and developmental mechanisms. Here we show that variation in the sizes of discrete neural systems in songbirds, a species-rich group exhibiting diverse behavioural and ecological specializations, supports major elements of both models. In accordance with the concerted model, most variation in nucleus volumes is shared across functional domains and allometry is related to developmental sequence. Per the mosaic model, residual variation in nucleus volumes is correlated within functional systems and predicts specific behavioural capabilities. These comparisons indicate that oscine brains evolved primarily as a coordinated whole but also experienced significant, independent modifications to dedicated systems from specific selection pressures. Finally, patterns of covariation between species and brain areas hint at underlying developmental mechanisms.

Evolving computational neural systems using synthetic developmental mechanisms

2003 ◽  
pp. 353-376 ◽  
Author(s):  
Alistair G. Rust ◽  
Rod Adams ◽  
Maria Schilstra ◽  
Hamid Bolouri
Keyword(s):  
Neural Systems ◽  
Developmental Mechanisms

The time when the “Tomte” of evolution was playing with time

2001 ◽  
Vol 24 (2) ◽  
pp. 287-287
Author(s):  
Giorgio M. Innocenti
Keyword(s):  
Developmental Plasticity ◽  
Brain Structures ◽  
Developmental Constraints ◽  
Developmental Mechanisms ◽  
Differential Expansion ◽  
High Degree ◽  
Adaptive Role

Developmental constraints presumably had a major role in channeling evolution. In particular, developmental mechanisms may have coordinated the evolution of neocortex with that of other brain structures. However, the rules determining the differential expansion of different cortical territories remain to be determined as well as the adaptive role of cortical expansion versus that of the structures it is connected to. The high degree of developmental plasticity of neocortex was probably the key to its successful evolution.

scholarly journals Traumatic brain injury in mice induces changes in the expression of the XCL1/XCR1 and XCL1/ITGA9 axes

2020 ◽  
Vol 72 (6) ◽  
pp. 1579-1592
Author(s):  
Agata Ciechanowska ◽  
Katarzyna Popiolek-Barczyk ◽  
Katarzyna Ciapała ◽  
Katarzyna Pawlik ◽  
Marco Oggioni ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Therapeutic Potential ◽  
Brain Structures ◽  
Pharmacological Intervention ◽  
Brain Areas ◽  
Cellular Origin ◽  
Protein Levels ◽  
Chemokine Ligand

Abstract Background Every year, millions of people suffer from various forms of traumatic brain injury (TBI), and new approaches with therapeutic potential are required. Although chemokines are known to be involved in brain injury, the importance of X-C motif chemokine ligand 1 (XCL1) and its receptors, X-C motif chemokine receptor 1 (XCR1) and alpha-9 integrin (ITGA9), in the progression of TBI remain unknown. Methods Using RT-qPCR/Western blot/ELISA techniques, changes in the mRNA/protein levels of XCL1 and its two receptors, in brain areas at different time points were measured in a mouse model of TBI. Moreover, their cellular origin and possible changes in expression were evaluated in primary glial cell cultures. Results Studies revealed the spatiotemporal upregulation of the mRNA expression of XCL1, XCR1 and ITGA9 in all the examined brain areas (cortex, thalamus, and hippocampus) and at most of the evaluated stages after brain injury (24 h; 4, 7 days; 2, 5 weeks), except for ITGA9 in the thalamus. Moreover, changes in XCL1 protein levels occurred in all the studied brain structures; the strongest upregulation was observed 24 h after trauma. Our in vitro experiments proved that primary murine microglial and astroglial cells expressed XCR1 and ITGA9, however they seemed not to be a main source of XCL1. Conclusions These findings indicate that the XCL1/XCR1 and XCL1/ITGA9 axes may participate in the development of TBI. The XCL1 can be considered as one of the triggers of secondary injury, therefore XCR1 and ITGA9 may be important targets for pharmacological intervention after traumatic brain injury. Graphic abstract

Neural Mechanisms of Visual Attention: Object-Based Selection of a Region in Space

2000 ◽  
Vol 12 (supplement 2) ◽  
pp. 106-117 ◽  
Author(s):  
Catherine M. Arrington ◽  
Thomas H. Carr ◽  
Andrew R. Mayer ◽  
Stephen M. Rao
Keyword(s):  
Visual Attention ◽  
Spatial Attention ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Brain Structures ◽  
Brain Regions ◽  
Brain Areas ◽  
Unbounded Region ◽  
Object Based ◽  
Selection Of

Objects play an important role in guiding spatial attention through a cluttered visual environment. We used event-related functional magnetic resonance imaging (ER-fMRI) to measure brain activity during cued discrimination tasks requiring subjects to orient attention either to a region bounded by an object (object-based spatial attention) or to an unbounded region of space (location-based spatial attention) in anticipation of an upcoming target. Comparison between the two tasks revealed greater activation when attention selected a region bounded by an object. This activation was strongly lateralized to the left hemisphere and formed a widely distributed network including (a) attentional structures in parietal and temporal cortex and thalamus, (b) ventral-stream object processing structures in occipital, inferior-temporal, and parahippocampal cortex, and (c) control structures in medial-and dorsolateral-prefrontal cortex. These results suggest that object-based spatial selection is achieved by imposing additional constraints over and above those processes already operating to achieve selection of an unbounded region. In addition, ER-fMRI methodology allowed a comparison of validly versus invalidly cued trials, thereby delineating brain structures involved in the reorientation of attention after its initial deployment proved incorrect. All areas of activation that differentiated between these two trial types resulted from greater activity during the invalid trials. This outcome suggests that all brain areas involved in attentional orienting and task performance in response to valid cues are also involved on invalid trials. During invalid trials, additional brain regions are recruited when a perceiver recovers from invalid cueing and reorients attention to a target appearing at an uncued location. Activated brain areas specific to attentional reorientation were strongly right-lateralized and included posterior temporal and inferior parietal regions previously implicated in visual attention processes, as well as prefrontal regions that likely subserve control processes, particularly related to inhibition of inappropriate responding.

scholarly journals Spatial and Temporal Expression of High-Mobility-Group Nucleosome-Binding (HMGN) Genes in Brain Areas Associated with Cognition in Individuals with Down Syndrome

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 2000
Author(s):  
Alejandra Rodríguez-Ortiz ◽  
Julio César Montoya-Villegas ◽  
Felipe García-Vallejo ◽  
Yecid Mina-Paz
Keyword(s):  
Down Syndrome ◽  
Differential Expression ◽  
Protein Interactions ◽  
Strong Evidence ◽  
High Mobility ◽  
Brain Structures ◽  
Microarray Experiment ◽  
High Mobility Group ◽  
Postmortem Brain ◽  
Brain Areas

DNA methylation and histone posttranslational modifications are epigenetics processes that contribute to neurophenotype of Down Syndrome (DS). Previous reports present strong evidence that nonhistone high-mobility-group N proteins (HMGN) are epigenetic regulators. They play important functions in various process to maintain homeostasis in the brain. We aimed to analyze the differential expression of five human HMGN genes in some brain structures and age ranks from DS postmortem brain samples. Methodology: We performed a computational analysis of the expression of human HMGN from the data of a DNA microarray experiment (GEO database ID GSE59630). Using the transformed log2 data, we analyzed the differential expression of five HMGN genes in several brain areas associated with cognition in patients with DS. Moreover, using information from different genome databases, we explored the co-expression and protein interactions of HMNGs with the histones of nucleosome core particle and linker H1 histone. Results: We registered that HMGN1 and HMGN5 were significantly overexpressed in the hippocampus and areas of prefrontal cortex including DFC, OFC, and VFC of DS patients. Age-rank comparisons between euploid control and DS individuals showed that HMGN2 and HMGN4 were overexpressed in the DS brain at 16 to 22 gestation weeks. From the BioGRID database, we registered high interaction scores of HMGN2 and HMGN4 with Hist1H1A and Hist1H3A. Conclusions: Overall, our results give strong evidence to propose that DS would be an epigenetics-based aneuploidy. Remodeling brain chromatin by HMGN1 and HMGN5 would be an essential pathway in the modification of brain homeostasis in DS.

Pentobarbital produces dissimilar changes in glucose influx and utilization in brain

1991 ◽  
Vol 261 (2) ◽  
pp. R265-R275
Author(s):  
T. Otsuka ◽  
L. Wei ◽  
D. Bereczki ◽  
V. Acuff ◽  
C. Patlak ◽  
...  
Keyword(s):  
Glucose Utilization ◽  
Brain Structures ◽  
Maximal Velocity ◽  
Local Cerebral Glucose Utilization ◽  
Brain Areas ◽  
Influx Rate ◽  
Half Saturation Constant ◽  
Permeability Surface ◽  
Area Product ◽  
Glucose Carrier

The effects of pentobarbital sodium on local cerebral glucose utilization (LCGU) and 3-O-methylglucose (3-MG) influx were measured by quantitative autoradiography in 52 brain areas of control and treated rats. Pentobarbital (50 mg/kg ip) lowered LCGU to a relatively uniform rate (approximately 35 mumol.100 g-1.min-1) in 24 of 25 forebrain areas. Among the 18 hindbrain areas, LCGU was decreased by pentobarbital by 15-55% (range 50-157 and 28-110 mumol.100 g-1.min-1 in control and treated rats, respectively). In contrast, pentobarbital lowered the 3-MG influx rate constant and permeability-surface area product by 20-30% in nearly all brain structures. The 3-MG results fit a model in which both the half-saturation constant and the maximal velocity of the glucose carrier are decreased by pentobarbital. After pentobarbital treatment, the ratio of local cerebral plasma flow (LCPF) to LCGU was the same as in controls for brain areas in which LCGU was less than 35 mumol.100 g-1.min-1 but was higher in brain areas where LCGU exceeded 35 mumol.100 g-1.min-1. Pentobarbital produced dissimilar changes in LCGU, 3-MG influx, and LCPF; these processes may thus not be closely linked during pentobarbital anesthesia.

How Musical Activity Shapes Memory

2020 ◽  
Vol 31 (2) ◽  
pp. 55-61 ◽  
Author(s):  
Martina Hoffmann ◽  
Christoph J. Ploner ◽  
Alexander Schmidt
Keyword(s):  
Elderly Population ◽  
Brain Plasticity ◽  
Brain Structures ◽  
The Elderly ◽  
Memory Capacity ◽  
Musical Instrument ◽  
Brain Areas ◽  
Memory Functioning ◽  
Musical Activity ◽  
The Brain

Abstract. Musical activity has been found to drive plasticity in brain areas involved in the process of playing a musical instrument. The present article reviews how musical activity influences the brain structures involved in memory and how it impacts on memory functioning memory functioning. Musical activity appears to be associated with better memory capacity across the lifespan. Importantly, training-induced effects are not restricted to childhood, but can occur even in the elderly population. We conclude by outlining how musical activity, both on the receptive and active level, can be beneficial to patients suffering from memory disorders, inducing brain plasticity and memory improvement.

Variation in local cerebral blood flow response to high-dose pentobarbital sodium in the rat

1991 ◽  
Vol 261 (1) ◽  
pp. H110-H120 ◽  
Author(s):  
T. Otsuka ◽  
L. Wei ◽  
V. R. Acuff ◽  
A. Shimizu ◽  
K. D. Pettigrew ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Gray Matter ◽  
Intraperitoneal Administration ◽  
Brain Structures ◽  
High Dose ◽  
Local Cerebral Blood Flow ◽  
Brain Areas ◽  
Pentobarbital Sodium ◽  
High Doses

Microvascular bed structure and functions are known to vary throughout the brain. Microvascular responses to high doses of pentobarbital sodium might therefore differ among brain areas. This possibility was examined by measuring local cerebral blood flow (LCBF) with [14C]iodoantipyrine in 52 brain areas at 5, 10, 25, and 60 min after intraperitoneal administration of pentobarbital (50 mg/kg). From 5 to 60 min, LCBF was significantly lowered in 17 of 25 forebrain gray matter areas but in only 1 of 18 hindbrain gray matter structures, the pontine nuclei. Smaller, shorter duration lowering of LCBF was also observed in ten other brain areas. In both control and treated rats, LCBF was found to vary within individual brain structures. The pattern of these LCBF variations was columnar in the cerebral cortex and the hippocampus but was patchy in the caudate-putamen, thalamus, and inferior colliculus. These results indicate that pentobarbital anesthesia more strongly alters LCBF in the forebrain than in the hindbrain and produces different patterns of changes in LCBF than in local cerebral glucose utilization, which was measured with 2-deoxyglucose in a companion study.

scholarly journals Recurrent neural network models of multi-area computation underlying decision-making

2019 ◽  
Author(s):  
Michael Kleinman ◽  
Chandramouli Chandrasekaran ◽  
Jonathan C. Kao
Keyword(s):  
Premotor Cortex ◽  
Network Models ◽  
Brain Regions ◽  
Neural Systems ◽  
Neural Network Models ◽  
Orthogonal Direction ◽  
Brain Areas ◽  
Dynamical Mechanism ◽  
Decision Variables ◽  
Direction Information

AbstractCognition emerges from coordinated computations across multiple brain areas. However, elucidating these computations within and across brain regions is challenging because intra- and inter-area connectivity are typically unknown. To study coordinated computation, we trained multi-area recurrent neural networks (RNNs) to discriminate the dominant color of a checker-board and output decision variables reflecting a direction decision, a task previously used to investigate decision-related dynamics in dorsal premotor cortex (PMd) of monkeys. We found that multi-area RNNs, trained with neurophysiological connectivity constraints and Dale’s law, recapitulated decision-related dynamics observed in PMd. The RNN solved this task by a dynamical mechanism where the direction decision was computed and outputted, via precisely oriented dynamics, on an axis that was nearly orthogonal to checkerboard color inputs. This orthogonal direction information was preferentially propagated through alignment with inter-area connections; in contrast, color information was filtered. These results suggest that cortex uses modular computation to generate minimal sufficient representations of task information. Finally, we used multi-area RNNs to produce experimentally testable hypotheses for computations that occur within and across multiple brain areas, enabling new insights into distributed computation in neural systems.

Why Is Navigation the Preferred PIM Retrieval Method?

2016 ◽  
Author(s):  
Ofer Bergman ◽  
Steve Whittaker
Keyword(s):  
Cognitive Psychology ◽  
Real World ◽  
Dual Task ◽  
Brain Structures ◽  
Linguistic Processing ◽  
Brain Areas ◽  
Retrieval Method ◽  
Language System ◽  
Dual Task Paradigm ◽  
Automatic Activation

This chapter explores fundamental reasons for navigation preference. It explores cognitive and neuroscience explanations about why navigation is preferred to search. Two studies reveal that navigation is less cognitively demanding than search. The first uses a cognitive psychology technique, the dual-task paradigm, to show that search requires more verbal attention than navigation. The second study indicates that PIM navigation involves primitive brain structures previously observed during real-world navigation. In contrast, search activates brain areas commonly observed in linguistic processing. These deep-rooted neurological biases may promote automatic activation of location-related retrieval, leaving the language system available for other tasks.

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