Hippocampal CA2 activity patterns change over time to a larger extent than between spatial contexts.
Ontology highlight
ABSTRACT:
SUBMITTER: Mankin EA
PROVIDER: S-EPMC4392894 | biostudies-literature | 2015 Jan
REPOSITORIES: biostudies-literature
Publications
Hippocampal CA2 activity patterns change over time to a larger extent than between spatial contexts.
Mankin Emily A EA Diehl Geoffrey W GW Sparks Fraser T FT Leutgeb Stefan S Leutgeb Jill K JK
Neuron 20150101 1
The hippocampal CA2 subregion has a different anatomical connectivity pattern within the entorhino-hippocampal circuit than either the CA1 or CA3 subregion. Yet major differences in the neuronal activity patterns of CA2 compared with the other CA subregions have not been reported. We show that standard spatial and temporal firing patterns of individual hippocampal principal neurons in behaving rats, such as place fields, theta modulation, and phase precession, are also present in CA2, but that t ...[more]
Similar Datasets
Project description:The hippocampus supports a cognitive map of space and is critical for encoding declarative memory (who, what, when and where). Recent studies have implicated hippocampal subfield CA2 in social and contextual memory but how it does so remains unknown. Here we find that in adult male rats, presentation of a social stimulus (novel or familiar rat) or a novel object induces global remapping of place fields in CA2 with no effect on neuronal firing rate or immediate early gene expression. This remapping did not occur in CA1, suggesting this effect is specific for CA2. Thus, modification of existing spatial representations might be a potential mechanism by which CA2 encodes social and novel contextual information.
| S-EPMC4737730 | biostudies-literature
Project description:Hippocampal place cells are functional units of spatial navigation and are present in all subregions: CA1, CA2, CA3, and CA4. Recent studies on CA2 have indicated its role in social and contextual memories, but its contribution to spatial novelty detection and encoding remains largely unknown. The current study aims to uncover how CA2 processes spatial novelty and to distinguish its functional role towards the same from CA1. Accordingly, a novel 3-day paradigm was designed where animals were introduced to a completely new environment on the first day, and on subsequent days, novel segments were inserted into the existing spatial environment while the other segments remained the same, allowing us to compare novel and familiar parts of the same closed-loop track on multiple days. We found that spatial novelty leads to dynamic and complex hippocampal place cell firings at both individual neuron and population levels. Place cells in both CA1 and CA2 had strong responses to novel segments, leading to higher average firing rates and increased pairwise cross correlations across all days. However, CA2 place cells that fired for novel areas had lower spatial information scores than CA1 place cells active in the same areas. At the ensemble level, CA1 only responded to spatial novelty on day 1, when the environment was completely novel, whereas CA2 responded to it on all days, each time novelty was introduced. Therefore, CA2 was more sensitive and responsive to novel spatial features even when introduced in a familiar environment, unlike CA1.
| S-EPMC9393711 | biostudies-literature
Project description:During walking, uneven surfaces impose new demands for controlling balance and forward progression at each step. It is unknown to what extent walking may be refined given an amount of stride-to-stride unpredictability at the distal level. Here, we explored the effects of an uneven terrain surface on whole-body locomotor dynamics immediately following exposure and after a familiarization period. Eleven young, unimpaired adults walked for 12 min on flat and uneven terrain treadmills. The whole-body center of mass excursion range (COMexc) and peak velocity (COMvel), step length and width were estimated. On first exposure to uneven terrain, we saw significant increases in medial-lateral COMexc and lateral COMvel, and in the variability of COMexc, COMvel and foot placement in both anterior-posterior and medial-lateral directions. Increases in step width and decreases in step length supported the immediate adoption of a cautious, restrictive solution on uneven terrain. After familiarization, step length increased and the variability of anterior-posterior COMvel and step length reduced, while step width and lateral COMvel reduced, alluding to a refinement of movement and a reduction of conservative strategies over time. However, the variability of medial-lateral COMexc and lateral COMvel increased, consistent with the release of previously constrained degrees of freedom. Despite this increase in variability, a strong relationship between step width and medial-lateral center of mass movement was maintained. Our results indicate that movement strategies of unimpaired adults when walking on uneven terrain can evolve over time with longer exposure to the surface.
| S-EPMC6679350 | biostudies-literature
Project description:The early years of marriage are a time of significant personal and relational changes as partners adjust to their new roles, but the specific ways that spouses' personalities may change in early marriage and how these changes are associated with spouses' marital satisfaction trajectories have been overlooked. Using 3 waves of data collected over the first 18 months of marriage (N = 338 spouses, or 169 heterosexual newlywed marriages), we examined changes in spouses' self-reported Big 5 personality traits over time and the association between initial levels and changes in personality and spouses' concurrent marital satisfaction trajectories. Results indicated significant changes in personality over time, including declines in agreeableness for husbands and for wives, declines in extraversion for husbands, declines in openness and neuroticism for wives, and increases in conscientiousness for husbands. These results did not differ by spouses' age, demographics, relationship length prior to marriage, cohabitation prior to marriage, initial marital satisfaction, or parenthood status. Initial levels of personality as well as changes in personality over time were associated with spouses' marital satisfaction trajectories. Taken together, these findings indicate that newlywed spouses' personalities undergo meaningful changes during the newlywed years and these changes are associated with changes in spouses' marital satisfaction. Further research is needed to understand the processes underlying changes in personality early in marriage and to examine the mechanisms linking changes in personality and changes in marital satisfaction. (PsycINFO Database Record
| S-EPMC5962362 | biostudies-literature
Project description:Greenhouse gas (GHG) emissions affect precipitation worldwide. The response is commonly described by two timescales linked to different processes: a rapid adjustment to radiative forcing, followed by a slower response to surface warming. However, additional timescales exist in the surface-warming response, tied to the time evolution of the sea-surface-temperature (SST) response. Here, we show that in climate model projections, the rapid adjustment and surface mean warming are insufficient to explain the time evolution of the hydro-climate response in three key Mediterranean-like areas-namely, California, Chile, and the Mediterranean. The time evolution of those responses critically depends on distinct shifts in the regional atmospheric circulation associated with the existence of distinct fast and slow SST warming patterns. As a result, Mediterranean and Chilean drying are in quasiequilibrium with GHG concentrations, meaning that the drying will not continue after GHG concentrations are stabilized, whereas California wetting will largely emerge only after GHG concentrations are stabilized. The rapid adjustment contributes to a reduction in precipitation, but has a limited impact on the balance between precipitation and evaporation. In these Mediterranean-like regions, future hydro-climate-related impacts will be substantially modulated by the time evolution of the pattern of SST warming that is realized in the real world.
| S-EPMC7060690 | biostudies-literature
Project description:Assuming that dispersal modes or abilities can explain the different responses of organisms to geographic or environmental distances, the distance-decay relationship is a useful tool to evaluate the relative role of local environmental structuring versus regional control in community composition. Based on continuing the current theoretical framework on metacommunity dynamics and based on the predictive effect of distance on community similarity, we proposed a new framework that includes the effect of spatial extent. In addition, we tested the validity of our proposal by studying the community similarity among three biotic groups with different dispersal modes (macrofaunal active and passive dispersers and plants) from two pond networks, where one network had a small spatial extent, and the other network had an extent that was 4 times larger. Both pond networks have similar environmental variability. Overall, we found that environmental distance had larger effects than geographical distances in both pond networks. Moreover, our results suggested that species sorting is the main type of metacommunity dynamics shaping all biotic groups when the spatial extent is larger. In contrast, when the spatial extent is smaller, the observed distance-decay patterns suggested that different biotic groups were mainly governed by different metacommunity dynamics. While the distance-decay patterns of active dispersers better fit the trend that was expected when mass effects govern a metacommunity, passive dispersers showed a pattern that was expected when species sorting prevails. Finally, in the case of plants, it is difficult to associate their distance-decay patterns with one type of metacommunity dynamics.
| S-EPMC6112654 | biostudies-other
Project description:BackgroundPre-lacteal feeding persists in low and middle-income countries as deep-rooted nutritional malpractice. It imposes significant negative consequences on neonatal health, including increased risk of illness and mortality. Different studies revealed that pre-lacteal feeding practice is decreased over time. Even though different studies are done on the prevalence and determinants of pre-lacteal feeding practice, up to our knowledge, the spatial distribution and the determinants of the change in pre-lacteal feeding practice over time are not researched.ObjectiveTo assess the spatial distribution and determinants of the change in pre-lacteal feeding practice over time in Ethiopia.MethodsWe used the Ethiopian demographic and health surveys (EDHSs) data. For this study, a total weighted sample of 14672 (5789 from EDHS 2005, 4510 from EDHS 2011, and 4373 from EDHS 2016) reproductive-age women who gave birth within two years preceding the respective surveys and whoever breastfeed were used. The logit-based multivariate decomposition analysis was used to identify factors that contributed to the decrease in pre-lacteal feeding practice over the last 10 years (from 2005 to 2016). Using the 2016 EDHS data, we also conducted a spatial analysis by using ArcGIS version 10.3 and SaTScan version 9.6 software to explore the spatial distribution and hotspot clusters of pre-lacteal feeding practice.ResultPre-lacteal feeding practice was decreased from 29% [95% Confidence interval (CI): 27.63-29.96%] in 2005 to 8% [95% CI: 7.72-8.83%] in 2016 with annual rate of reduction of 7.2%. The overall decomposition analysis showed that about 20.31% of the overall decrease in pre-lacteal feeding practice over the last 10 years was attributable to the difference in composition of women (endowment) across the surveys, while, the remaining 79.39% of the overall decrease was explained by the difference in the effect of characteristics (coefficient) across the surveys. In the endowment component, the difference in composition of residence, perception of distance from the health facility, maternal educational level, wealth status, occupation, ANC visit, place of delivery, the timing of breastfeeding initiation, and wanted last-child/pregnancy were found to be significant contributing factors for the decrease in pre-lacteal feeding practice. After controlling for the role of compositional changes, the difference in the effect of distance from the health facility, wealth status, occupation, antenatal care (ANC) visit, and wanted last-child/pregnancy across the surveys were significantly contributed to the observed decrease in pre-lacteal feeding practice. Regarding the spatial distribution, pre-lacteal feeding practice was non-random in Ethiopia in which the primary and secondary clusters' of pre-lacteal feeding identified in Somalia and the Afar region respectively.ConclusionPre-lacteal feeding practice has shown a significant decline over the 10-year period. Program interventions considering women with poor maternal health service utilization such as ANC visits, women with poor socioeconomic status, women with an unintended pregnancy, and women from remote areas especially at border areas such as Somali and Afar could decrease pre-lacteal feeding practice in Ethiopia.
| S-EPMC7808656 | biostudies-literature
Project description:PurposeIntensive care interventions that prolong life without achieving meaningful benefit are considered clinically "inappropriate". In 2012, the frequency of perceived-inappropriate critical care was 10.8% at one academic health system; and we aimed to re-evaluate this frequency.MethodsFor 4 months in 2017, we surveyed critical care physicians daily and asked whether each patient was receiving appropriate, probably inappropriate, or inappropriate critical care. Patients were categorized into three groups: 1) patients for whom treatment was never inappropriate, 2) patients with at least one assessment that treatment was probably inappropriate, but no inappropriate treatment assessments, and 3) patients who had at least one assessment of inappropriate treatment.ResultsFifty-five physicians made 10,105 assessments on 1424 patients. Of these, 94 (6.6%) patients received at least one assessment of inappropriate critical care, which is lower than 2012 (10.8% (p < 0.01)). Comparing 2017 and 2012, patient age, MS-DRG, length of stay, and hospital mortality were not significantly different (p > 0.05). Inpatient mortality in 2017 was 73% for patients receiving inappropriate critical care.ConclusionsOver five years the proportion of patients perceived to be receiving inappropriate critical care dropped by 40%. Understanding the reasons for such change might elucidate how to continue to reduce inappropriate critical care.
| S-EPMC7736139 | biostudies-literature
Project description:When an action is familiar, we are able to anticipate how it will change the state of the world. These expectations can result from retrieval of action-outcome associations in the hippocampus and the reinstatement of anticipated outcomes in visual cortex. How does this role for the hippocampus in action-based prediction change over time? We use high-resolution fMRI and a dual-training behavioral paradigm to examine how the hippocampus interacts with visual cortex during predictive and nonpredictive actions learned either three days earlier or immediately before the scan. Just-learned associations led to comparable background connectivity between the hippocampus and V1/V2, regardless of whether actions predicted outcomes. However, three-day-old associations led to stronger background connectivity and greater differentiation between neural patterns for predictive vs. nonpredictive actions. Hippocampal prediction may initially reflect indiscriminate binding of co-occurring events, with action information pruning weaker associations and leading to more selective and accurate predictions over time.
| S-EPMC6728336 | biostudies-literature
Project description:The amygdala and hippocampus are two adjacent allocortical structures implicated in sex-biased and developmentally-emergent psychopathology. However, the spatiotemporal dynamics of amygdalo-hippocampal development remain poorly understood in healthy humans. The current study defined trajectories of volume and shape change for the amygdala and hippocampus by applying a multi-atlas segmentation pipeline (MAGeT-Brain) and semi-parametric mixed-effects spline modeling to 1,529 longitudinally-acquired structural MRI brain scans from a large, single-center cohort of 792 youth (403 males, 389 females) between the ages of 5 and 25 years old. We found that amygdala and hippocampus volumes both follow curvilinear and sexually dimorphic growth trajectories. These sex-biases were particularly striking in the amygdala: males showed a significantly later and slower adolescent deceleration in volume expansion (at age 20 years) than females (age 13 years). Shape analysis localized significant hot-spots of sex-biased anatomical development in sub-regional territories overlying rostral and caudal extremes of the CA1/2 in the hippocampus, and the centromedial nuclear group of the amygdala. In both sexes, principal components analysis revealed close integration of amygdala and hippocampus shape change along two main topographically-organized axes - low vs. high areal expansion, and early vs. late growth deceleration. These results (i) bring greater resolution to our spatiotemporal understanding of amygdalo-hippocampal development in healthy males and females, and (ii) uncover focal sex-differences in the structural maturation of the brain components that may contribute to differences in behavior and psychopathology that emerge during adolescence.
| S-EPMC7485527 | biostudies-literature