scholarly journals Time Regained: How the Human Brain Constructs Memory for Time

2017 ◽  
Author(s):  
Brendan I. Cohn-Sheehy ◽  
Charan Ranganath
Keyword(s):  
Prefrontal Cortex ◽  
Human Brain ◽  
Event Structure ◽  
Cortical Network ◽  
Temporal Information ◽  
Temporal Contiguity ◽  
Temporal Context ◽  
List Type ◽  
Temporal Memory ◽  
Cortical Areas

AbstractLife’s episodes unfold against a context that changes with time. Recent neuroimaging studies have revealed significant findings about how specific areas of the human brain may support the representation of temporal information in memory. A consistent theme in these studies is that the hippocampus appears to play a central role in representing temporal context, as operationalized in neuroimaging studies of arbitrary lists of items, sequences of items, or meaningful, lifelike events. Additionally, activity in a posterior medial cortical network may reflect the representation of generalized temporal information for meaningful events. The hippocampus, posterior medial network, and other regions—particularly in prefrontal cortex—appear to play complementary roles in memory for temporal context.HighlightsThe hippocampus encodes information about temporal contiguity, order, and event structure.Posterior medial cortical areas represent order across meaningfully coherent events.Prefrontal and subcortical contributions to temporal memory deserve further study.

Histochemical identification of cortical areas in the auditory region of the human brain

2002 ◽  
Vol 143 (4) ◽  
pp. 499-508 ◽  
Author(s):  
Mark N. Wallace ◽  
Peter W. Johnston ◽  
Alan R. Palmer
Keyword(s):  
Human Brain ◽  
Cortical Areas ◽  
Auditory Region ◽  
Histochemical Identification

scholarly journals SNAP-25a/b Isoform Levels in Human Brain Dorsolateral Prefrontal Cortex and Anterior Cingulate Cortex

2015 ◽  
Vol 1 (4) ◽  
pp. 220-234 ◽  
Author(s):  
Peter M. Thompson ◽  
Dianne A. Cruz ◽  
Elizabeth A. Fucich ◽  
Dianna Y. Olukotun ◽  
Masami Takahashi ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Human Brain ◽  
Anterior Cingulate Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Dorsolateral Prefrontal

scholarly journals Statistical Comparison of Spike Responses to Natural Stimuli in Monkey Area V1 With Simulated Responses of a Detailed Laminar Network Model for a Patch of V1

2011 ◽  
Vol 105 (2) ◽  
pp. 757-778 ◽  
Author(s):  
Malte J. Rasch ◽  
Klaus Schuch ◽  
Nikos K. Logothetis ◽  
Wolfgang Maass
Keyword(s):  
Network Model ◽  
Network Models ◽  
Cortical Network ◽  
Inhibitory Neurons ◽  
Sensory Stimuli ◽  
Natural Stimuli ◽  
Cortical Areas ◽  
Model Response ◽  
Spiking Activity

A major goal of computational neuroscience is the creation of computer models for cortical areas whose response to sensory stimuli resembles that of cortical areas in vivo in important aspects. It is seldom considered whether the simulated spiking activity is realistic (in a statistical sense) in response to natural stimuli. Because certain statistical properties of spike responses were suggested to facilitate computations in the cortex, acquiring a realistic firing regimen in cortical network models might be a prerequisite for analyzing their computational functions. We present a characterization and comparison of the statistical response properties of the primary visual cortex (V1) in vivo and in silico in response to natural stimuli. We recorded from multiple electrodes in area V1 of 4 macaque monkeys and developed a large state-of-the-art network model for a 5 × 5-mm patch of V1 composed of 35,000 neurons and 3.9 million synapses that integrates previously published anatomical and physiological details. By quantitative comparison of the model response to the “statistical fingerprint” of responses in vivo, we find that our model for a patch of V1 responds to the same movie in a way which matches the statistical structure of the recorded data surprisingly well. The deviation between the firing regimen of the model and the in vivo data are on the same level as deviations among monkeys and sessions. This suggests that, despite strong simplifications and abstractions of cortical network models, they are nevertheless capable of generating realistic spiking activity. To reach a realistic firing state, it was not only necessary to include both N -methyl-d-aspartate and GABAB synaptic conductances in our model, but also to markedly increase the strength of excitatory synapses onto inhibitory neurons (>2-fold) in comparison to literature values, hinting at the importance to carefully adjust the effect of inhibition for achieving realistic dynamics in current network models.

scholarly journals Glucagon Like Peptide-1 and Its Receptor in Human Brain: Distribution of Expression, Functional Implications, Age Related Changes & Species Specific Characteristics

2021 ◽  
Author(s):  
Tulika Gupta ◽  
◽  
Mandeep Kaur ◽  
Devendra Shekhawat ◽  
Ritu Aggarwal ◽  
...  
Keyword(s):  
Human Brain ◽  
Frontal Cortex ◽  
Brain Mapping ◽  
Treatment Options ◽  
Cortical Areas ◽  
Western Blot Method ◽  
Age Related ◽  
Immuno Histochemistry ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Emerging evidence has shown that the Glucagon like peptide-1 (GLP-1) agonist can be used for treating Alzheimer’s disease, but knowledge of its neural targets is limited. To understand the neural substrates of GLP-1, we have done whole brain mapping for GLP-1 and its receptor (GLP-1R), in 30 human brains. GLP-1 expression was studied by immuno-histochemistry and confirmed by western blot method. GLP-1R gene expression was studied by RT-PCR. GLP-1 expression was seen in most of the cortical areas (maximum in frontal, prefrontal & parietal cortex), diencephalon and brainstem, but not in cerebellum. Protein expression studies validated these results. Highest expression of GLP-1R was found in the frontal cortex. The orbito-frontal cortex and cerebellum had negligible expression. Hippocampus demonstrated significant presence of GLP-1R but patchy immunoreactivity to GLP-1. GLP-1R presence in most of the human cortical regions and absence in cerebellum is the major deviation from the animal brain. Sites which might be of interest in Alzheimer’s have been identified. GLP-1 demonstrated age related decline in most of the areas after 5thdecade. At 60yrs GLP-1 was not found in any of the cortical areas except in the prefrontal cortex but it was present in the sub-cortical areas. Age related profiling of GLP-1 in various brain areas has been analysed, which can have important bearing on understanding the Alzheimer’s. This study provides detailed description of GLP-1 and GLP-1R locations by complete human brain mapping for the first time and may lead to novel treatment options targeting the GLP-1 receptors.

scholarly journals Subjective value and decision entropy are jointly encoded by aligned gradients across the human brain

2020 ◽  
Author(s):  
Sebastian Bobadilla-Suarez ◽  
Olivia Guest ◽  
Bradley C. Love
Keyword(s):  
Prefrontal Cortex ◽  
Human Brain ◽  
Ventromedial Prefrontal Cortex ◽  
Neural Representation ◽  
Retrospective Evaluation ◽  
Systematic Fashion ◽  
Subjective Value ◽  
Fmri Analysis ◽  
The Relationship ◽  
The Brain

AbstractRecent work has considered the relationship between value and confidence in both behavior and neural representation. Here we evaluated whether the brain organizes value and confidence signals in a systematic fashion that reflects the overall desirability of options. If so, regions that respond to either increases or decreases in both value and confidence should be widespread. We strongly confirmed these predictions through a model-based fMRI analysis of a mixed gambles task that assessed subjective value (SV) and inverse decision entropy (iDE), which is related to confidence. Purported value areas more strongly signalled iDE than SV, underscoring how intertwined value and confidence are. A gradient tied to the desirability of actions transitioned from positive SV and iDE in ventromedial prefrontal cortex to negative SV and iDE in dorsal medial prefrontal cortex. This alignment of SV and iDE signals could support retrospective evaluation to guide learning and subsequent decisions.

scholarly journals Distinct cortical systems reinstate the content and context of episodic memories

2020 ◽  
Author(s):  
James E. Kragel ◽  
Youssef Ezzyat ◽  
Bradley C. Lega ◽  
Michael R. Sperling ◽  
Gregory A. Worrell ◽  
...  
Keyword(s):  
Free Recall ◽  
Functional Connectivity ◽  
Human Brain ◽  
Semantic Content ◽  
Cortical Activity ◽  
Temporal Context ◽  
Cortical Networks ◽  
Semantic Organization ◽  
Episodic Memories

AbstractEpisodic recall depends upon the reinstatement of cortical activity present during the formation of a memory. We identified dissociable cortical networks via functional connectivity that uniquely reinstated semantic content and temporal context of previously studied stimuli during free recall. Network-specific reinstatement predicted the temporal and semantic organization of recall sequences, demonstrating how specialized cortical systems enable the human brain to target specific memories.

Sign in / Sign up

Export Citation Format

Share Document