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Cognitive memory and mapping in a brain-like system for robotic navigation. Neural Netw 2016; 87:27-37. [PMID: 28064015 DOI: 10.1016/j.neunet.2016.08.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 07/01/2016] [Accepted: 08/04/2016] [Indexed: 11/21/2022]
Abstract
Electrophysiological studies in animals may provide a great insight into developing brain-like models of spatial cognition for robots. These studies suggest that the spatial ability of animals requires proper functioning of the hippocampus and the entorhinal cortex (EC). The involvement of the hippocampus in spatial cognition has been extensively studied, both in animal as well as in theoretical studies, such as in the brain-based models by Edelman and colleagues. In this work, we extend these earlier models, with a particular focus on the spatial coding properties of the EC and how it functions as an interface between the hippocampus and the neocortex, as proposed by previous work. By realizing the cognitive memory and mapping functions of the hippocampus and the EC, respectively, we develop a neurobiologically-inspired system to enable a mobile robot to perform task-based navigation in a maze environment.
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Hu J, Tang H, Tan K, Li H. How the Brain Formulates Memory: A Spatio-Temporal Model Research Frontier. IEEE COMPUT INTELL M 2016. [DOI: 10.1109/mci.2016.2532268] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Yin X, Gao Y, Shi HS, Song L, Wang JC, Shao J, Geng XH, Xue G, Li JL, Hou YN. Overexpression of SIRT6 in the hippocampal CA1 impairs the formation of long-term contextual fear memory. Sci Rep 2016; 6:18982. [PMID: 26732053 PMCID: PMC4702175 DOI: 10.1038/srep18982] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 12/02/2015] [Indexed: 12/31/2022] Open
Abstract
Histone modifications have been implicated in learning and memory. Our previous transcriptome data showed that expression of sirtuins 6 (SIRT6), a member of Histone deacetylases (HDACs) family in the hippocampal cornu ammonis 1 (CA1) was decreased after contextual fear conditioning. However, the role of SIRT6 in the formation of memory is still elusive. In the present study, we found that contextual fear conditioning inhibited translational expression of SIRT6 in the CA1. Microinfusion of lentiviral vector-expressing SIRT6 into theCA1 region selectively enhanced the expression of SIRT6 and impaired the formation of long-term contextual fear memory without affecting short-term fear memory. The overexpression of SIRT6 in the CA1 had no effect on anxiety-like behaviors or locomotor activity. Also, we also found that SIRT6 overexpression significantly inhibited the expression of insulin-like factor 2 (IGF2) and amounts of proteins and/or phosphoproteins (e.g. Akt, pAkt, mTOR and p-mTOR) related to the IGF2 signal pathway in the CA1. These results demonstrate that the overexpression of SIRT6 in the CA1 impaired the formation of long-term fear memory, and SIRT6 in the CA1 may negatively modulate the formation of contextual fear memory via inhibiting the IGF signaling pathway.
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Affiliation(s)
- Xi Yin
- Department of Functional region of Diagnosis, Hebei Medical University Fourth Hospital, Hebei Medical University, Shijiazhuang 050011, China
| | - Yuan Gao
- Department of Biochemistry and Molecular Biology, College of basic medicine, Hebei Medical University, Shijiazhuang 050017, China
| | - Hai-Shui Shi
- Department of Biochemistry and Molecular Biology, College of basic medicine, Hebei Medical University, Shijiazhuang 050017, China.,Department of Pharmacy, the Bethune International Peace Hospital of PLA, Shijiazhuang 050082, China
| | - Li Song
- Department of Biochemistry and Molecular Biology, College of basic medicine, Hebei Medical University, Shijiazhuang 050017, China
| | - Jie-Chao Wang
- Department of vasculocardiology, Hebei Province Geriatric Hospital, Shijiazhuang, 050011, China
| | - Juan Shao
- Department of Senile Disease, the Third Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Xu-Hong Geng
- Department of Functional region of Diagnosis, Hebei Medical University Fourth Hospital, Hebei Medical University, Shijiazhuang 050011, China
| | - Gai Xue
- Department of Pharmacy, the Bethune International Peace Hospital of PLA, Shijiazhuang 050082, China
| | - Jian-Li Li
- Department of Pharmacy, the Bethune International Peace Hospital of PLA, Shijiazhuang 050082, China
| | - Yan-Ning Hou
- Department of Pharmacy, the Bethune International Peace Hospital of PLA, Shijiazhuang 050082, China
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Weledji EP, Assob JC. The ubiquitous neural cell adhesion molecule (N-CAM). Ann Med Surg (Lond) 2014; 3:77-81. [PMID: 25568792 PMCID: PMC4284440 DOI: 10.1016/j.amsu.2014.06.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 06/18/2014] [Accepted: 06/28/2014] [Indexed: 11/08/2022] Open
Abstract
Adhesive interactions are important for cell trafficking, differentiation, function and tissue differentiation. Neural cell adhesion molecule (NCAM) is involved in a diverse range of contact-mediated interactions among neurons, astrocytes, oligodendrocytes, and myotubes. It is widely but transiently expressed in many tissues early in embryogenesis. Four main isoforms exist but there are many other variants resulting from alternative splicing and post-translational modifications. This review discusses the actions and association of N-CAM and variants, PSA CAM. L1CAM and receptor tyrosine kinase. Their interactions with the interstitial cells of Cajal – the pacemaker cells of the gut in the manifestation of gut motility disorders, expression in carcinomas and mesenchymal tumours are discussed.
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Affiliation(s)
- Elroy P Weledji
- Department of Surgery, Faculty of Health Sciences, University of Buea, Cameroon
| | - Jules C Assob
- Biochemistry, Faculty of Health Sciences, University of Buea, Cameroon
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Sparse encoding of automatic visual association in hippocampal networks. Neuroimage 2014; 102 Pt 2:458-64. [PMID: 25038440 DOI: 10.1016/j.neuroimage.2014.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 06/11/2014] [Accepted: 07/12/2014] [Indexed: 11/21/2022] Open
Abstract
Intelligent action entails exploiting predictions about associations between elements of ones environment. The hippocampus and mediotemporal cortex are endowed with the network topology, physiology, and neurochemistry to automatically and sparsely code sensori-cognitive associations that can be reconstructed from single or partial inputs. Whilst acquiring fMRI data and performing an attentional task, participants were incidentally presented with a sequence of cartoon images. By assigning subjects a post-scan free-association task on the same images we assayed the density of associations triggered by these stimuli. Using multivariate Bayesian decoding, we show that human hippocampal and temporal neocortical structures host sparse associative representations that are automatically triggered by visual input. Furthermore, as predicted theoretically, there was a significant increase in sparsity in the Cornu Ammonis subfields, relative to the entorhinal cortex. Remarkably, the sparsity of CA encoding correlated significantly with associative memory performance over subjects; elsewhere within the temporal lobe, entorhinal, parahippocampal, perirhinal and fusiform cortices showed the highest model evidence for the sparse encoding of associative density. In the absence of reportability or attentional confounds, this charts a distribution of visual associative representations within hippocampal populations and their temporal lobe afferent fields, and demonstrates the viability of retrospective associative sampling techniques for assessing the form of reflexive associative encoding.
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Yu J, Tang H, Li H. Dynamics analysis of a population decoding model. IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 2013; 24:498-503. [PMID: 24808321 DOI: 10.1109/tnnls.2012.2236684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Information processing in the nervous system involves the activity of large populations of neurons. It is difficult to extract information from these population codes because of the noise inherent in neuronal responses. We propose a divisive normalization model to read the population codes. The dynamics of the model are analyzed by continuous attractor theory. Under certain conditions, the model possesses continuous attractors. Moreover, the explicit expressions of the continuous attractors are provided. Simulations are employed to illustrate the theory.
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