Network-dependent modulation of brain activity during sleep

AbstractBrain activity dynamically changes even during sleep. A line of neuroimaging studies has reported changes in functional connectivity and regional activity across different sleep stages such as slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. However, it remains unclear whether and how the large-scale network activity of human brains changes within a given sleep stage. Here, we investigated modulation of network activity within sleep stages by applying the pairwise maximum entropy model to brain activity obtained by functional magnetic resonance imaging from sleeping healthy subjects. We found that the brain activity of individual brain regions and functional interactions between pairs of regions significantly increased in the default-mode network during SWS and decreased during REM sleep. In contrast, the network activity of the fronto-parietal and sensory-motor networks showed the opposite pattern. Furthermore, in the three networks, the amount of the activity changes throughout REM sleep was negatively correlated with that throughout SWS. The present findings suggest that the brain activity is dynamically modulated even in a sleep stage and that the pattern of modulation depends on the type of the large-scale brain networks

Lateral–Medial Dissociation in Orbitofrontal Cortex–Hypothalamus Connectivity

The orbitofrontal cortex (OFC) is involved in cognitive functions, and is also closely related to autonomic functions. The OFC is densely connected with the hypothalamus, a heterogeneous structure controlling autonomic functions that can be divided into two major parts: the lateral and the medial. Resting-state functional connectivity has allowed us to parcellate the cerebral cortex into putative functional areas based on the changes in the spatial pattern of connectivity in the cerebral cortex when a seed point is moved from one voxel to another. In the present high spatial-resolution fMRI study, we investigate the connectivity-based organization of the OFC with reference to the hypothalamus. The OFC was parcellated using resting-state functional connectivity in an individual subject approach, and then the functional connectivity was examined between the parcellated areas in the OFC and the lateral/medial hypothalamus. We found a functional double dissociation in the OFC: the lateral OFC (the lateral orbital gyrus) was more likely connected with the lateral hypothalamus, whereas the medial OFC (the medial orbital and rectal gyri) was more likely connected with the medial hypothalamus. These results demonstrate the fundamental heterogeneity of the OFC, and suggest a potential neural basis of the OFC-hypothalamic functional interaction

Local Signal Time-Series during Rest Used for Areal Boundary Mapping in Individual Human Brains

It is widely thought that resting state functional connectivity likely reflects functional interaction among brain areas and that different functional areas interact with different sets of brain areas. A method for mapping areal boundaries has been formulated based on the large-scale spatial characteristics of regional interaction revealed by resting state functional connectivity. In the present study, we present a novel analysis for areal boundary mapping that requires only the signal timecourses within a region of interest, without reference to the information from outside the region. The areal boundaries were generated by the novel analysis and were compared with those generated by the previously-established standard analysis. The boundaries were robust and reproducible across the two analyses, in two regions of interest tested. These results suggest that the information for areal boundaries is readily available inside the region of interest

指導現場にみる肥満主婦の特徴 : 事例を通して

The favorite foods of obese women were snack and cereal before the dietary counseling class started. The obese women took care of having a low intake of oily foods and making a taste with low salt concentration. We often observed that they took shortage of foods as well as excess of ones. They repeated trials of the diet and had much amount of healthful food ingestions for concerning of their healthy life. After the class, the characteristics of the weight reduction group were decrease of taking snack foods and increase of the QOL, based on the balance sheet of food intake. These improvements were depended on the cooperation with their families. On the other hand, the non-weight reduction group was not improved because of the non-cooperation with their families

Within-Subject Correlation Analysis to Detect Functional Areas Associated With Response Inhibition

Functional areas in fMRI studies are often detected by brain-behavior correlation, calculating across-subject correlation between the behavioral index and the brain activity related to a function of interest. Within-subject correlation analysis is also employed in a single subject level, which utilizes cognitive fluctuations in a shorter time period by correlating the behavioral index with the brain activity across trials. In the present study, the within-subject analysis was applied to the stop-signal task, a standard task to probe response inhibition, where efficiency of response inhibition can be evaluated by the stop-signal reaction time (SSRT). Since the SSRT is estimated, by definition, not in a trial basis but from pooled trials, the correlation across runs was calculated between the SSRT and the brain activity related to response inhibition. The within-subject correlation revealed negative correlations in the anterior cingulate cortex and the cerebellum. Moreover, the dissociation pattern was observed in the within-subject analysis when earlier vs. later parts of the runs were analyzed: negative correlation was dominant in earlier runs, whereas positive correlation was dominant in later runs. Regions of interest analyses revealed that the negative correlation in the anterior cingulate cortex, but not in the cerebellum, was dominant in earlier runs, suggesting multiple mechanisms associated with inhibitory processes that fluctuate on a run-by-run basis. These results indicate that the within-subject analysis compliments the across-subject analysis by highlighting different aspects of cognitive/affective processes related to response inhibition

Transient activation during block transition

Functional MRI (fMRI) data analysis of blocked-task paradigms typically considers brain activity present across a temporally extended task block relative to a reference block. An open question remains as to whether processes evolving with distinct temporal profiles are also present and can inform us about further functional–anatomic processes underlying task performance. To explore this question, a meta-analysis of data from these separate studies was performed. The meta-analysis specifically focused on detecting transient activation occurring at the onset and offset of task blocks. The composite data set from 39 subjects included four distinct task conditions (from various intentional encoding paradigms) that had equivalent block timing. Task block activation included a network of regions consistent with prior analyses of intentional encoding. Activation related to the block transitions included a set of transiently activated regions, consistent across all four separate task conditions. The most prominent activation was found in right frontal cortex along the dorsal extent of inferior frontal gyrus (near BA 6/44). Importantly, in one condition, this transient activation was present in the absence of a response across the task block suggesting dissociation between processes in support of ongoing task demands and those associated with transitions between blocks. Other prominent transient activations included posterior superior temporal sulcus, medial occipitoparietal sulcus, anterior insula, and anterior cingulate sulcus in the right hemisphere. These findings are discussed in relation to models of set shifting and competitive interactions between brain regions

Transient activation during block transition

Functional MRI (fMRI) data analysis of blocked-task paradigms typically considers brain activity present across a temporally extended task block relative to a reference block. An open question remains as to whether processes evolving with distinct temporal profiles are also present and can inform us about further functional-anatomic processes underlying task performance. To explore this question, a meta-analysis of data from these separate studies was performed. The meta-analysis specifically focused on detecting transient activation occurring at the onset and offset of task blocks. The composite data set from 39 subjects included four distinct task conditions (from various intentional encoding paradigms) that had equivalent block timing. Task block activation included a network of regions consistent with prior analyses of intentional encoding. Activation related to the block transitions included a set of transiently activated regions, consistent across all four separate task conditions. The most prominent activation was found in right frontal cortex along the dorsal extent of inferior frontal gyrus (near BA 6/44). Importantly, in one condition, this transient activation was present in the absence of a response across the task block suggesting dissociation between processes in support of ongoing task demands and those associated with transitions between blocks. Other prominent transient activations included posterior superior temporal sulcus, medial occipitoparietal sulcus, anterior insula, and anterior cingulate sulcus in the right hemisphere. These findings are discussed in relation to models of set shifting and competitive interactions between brain regions.</p

Alloparenting for chimpanzee twins.

2歳のふたごチンパンジーに対して、母親以外のおとなも世話行動. 京都大学プレスリリース. 2014-09-12.In April 2009, a female chimpanzee named Sango, living in a captive group at the Noichi Zoo, Japan, gave birth to dizygotic male-female twin chimpanzees (male: Daiya, female: Sakura). The extent to which adult group members cared for the twins was investigated using a focal animal sampling method targeting six adults (one male) when the twin chimpanzees were two years old. Data were collected for an average of 6.78 h (SD = 0.79) per focal participant. An unaffiliated female adult of Sango was engaged in parenting Sakura as much as Sango. Given that Sakura was in lesser proximity to Sango than Daiya, Sakura's departures from her mother and her ability to gesture requests might have enabled non-kin adults to provide her care