The Nonhuman Primate Hippocampus: Neuroanatomy and Patterns of Cortical Connectivity

Insausti, Ricardo; Marcos, M; Mohedano-Moriano, Alicia; Arroyo-Jiménez, M.M.; Parada, Marta Córcoles; Artacho‐Pérula, Emilio; Ubero-Martínez, M. M.; López, Mayra

doi:10.1007/978-3-319-50406-3_1

Cited by 12 publications

(12 citation statements)

References 133 publications

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“…As suggested by Lavenex & Amaral (2000) there are also direct two-way connections between PHC, BA35 and BA36 (perirhinal cortex) and subiculum and CA1, captured with some degree of agreement by FASK and Two-Step. The presence of 2-cycles in the output of both algorithms is consistent with reported feedback in medial temporal lobe information processing (Insausti et al, 2017). There are two main discrepancies of our results with the standard model of the hippocampus as presented in Lavenex & Amaral (2000).…”

Section: Resting State Data Resultssupporting

confidence: 83%

Causal Discovery of Feedback Networks with Functional Magnetic Resonance Imaging

Sanchez-Romero

Ramsey

Zhang

et al. 2018

Preprint

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We test the adequacies of several proposed and two new statistical methods for recovering the causal structure of systems with feedback that generate noisy time series closely matching real BOLD time series. We compare: an adaptation for time series of the first correct method for recovering the structure of cyclic linear systems; multivariate Granger causal regression; the GIMME algorithm; the Ramsey et al. non-Gaussian methods; two non-Gaussian methods proposed by Hyvärinen and Smith; a method due to Patel, et al.; and the GlobalMIT algorithm. We introduce and also compare two new methods, the Fast Adjacency Skewness (FASK) and Two-Step, which exploit non-Gaussian features of the BOLD signal in different ways. We give theoretical justifications for the latter two algorithms. Our test models include feedback structures with and without direct feedback (2-cycles), excitatory and inhibitory feedback, models using experimentally determined structural connectivities of macaques, and empirical resting state and task data. We find that averaged over all of our simulations, including those with 2-cycles, several of these methods have a better than 80% orientation precision (i.e., the probability a directed edge is in the true generating structure given that a procedure estimates it to be so) and the two new methods also have better than 80% recall (probability of recovering an orientation in the data generating model). Recovering inhibitory direct feedback loops between two regions is especially challenging.

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Section: Resting State Data Resultssupporting

confidence: 83%

Causal Discovery of Feedback Networks with Functional Magnetic Resonance Imaging

Sanchez-Romero

Ramsey

Zhang

et al. 2018

Preprint

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“…One can think of this as a temporary ripple effect in an interconnected system, like an audience member fainting in the front row of a concert—they are not critical for the music, but the band will probably stop playing for a bit. The hippocampus is well‐connected (Insausti et al, ). For example, the parahippocampal cortex (Alvarado & Bachevalier, ; Bachevalier & Nemanic, ; Malkova & Mishkin, ) and thalamus (Isseroff et al, ) have both been implicated in nonnavigational spatial memory, and both share strong connections with the hippocampal formation.…”

Section: Discussionmentioning

confidence: 99%

“…One can think of this as a temporary ripple effect in an interconnected system, like an audience member fainting in the front row of a concert-they are not critical for the music, but the band will probably stop playing for a bit. The hippocampus is well-connected (Insausti et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

Nonnavigational spatial memory performance is unaffected by hippocampal damage in monkeys

Basile

Hampton

2018

Hippocampus

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Evidence that the hippocampus is critical for spatial memory in nonnavigational tests is mixed. A recent study reported that temporary hippocampal inactivation impaired spatial memory in the nonnavigational Hamilton Search Task in monkeys. However, several studies have documented no impairment on other nonnavigational spatial memory tests following permanent hippocampal lesions. It was hypothesized that transient, but not permanent, hippocampal disruption produces deficits because monkeys undergoing transient inactivation continue to try to use a hippocampal-dependent strategy, whereas monkeys with permanent lesions use a nonhippocampal-dependent strategy. We evaluated this hypothesis by testing five rhesus monkeys with hippocampal lesions and five controls on a computerized analogue of the Hamilton Search Task. On each trial, monkeys saw an array of squares on a touchscreen, each of which "hid" one reward. Retrieving a reward depleted that location and monkeys continued selecting squares until they found all rewards. The optimal strategy is to remember chosen locations and choose each square once. Unlike the inactivation study, monkeys with hippocampal damage were as accurate as controls regardless of retention interval. Critically, we found no evidence that the groups used different strategies, as measured by learning rates, spatial search biases, perseverative win-stay errors, or inter-choice distance. This discrepancy between the effect of inactivations and lesions may result from off-target effects of inactivations or as-yet-unidentified differences between the physical and computerized tasks. Combined with previous evidence that hippocampal damage impairs navigational memory in monkeys, this evidence constrains the role of the hippocampus in spatial memory as being critical for navigational tests that likely involve allocentric spatial memory but not nonnavigational tests that likely involve egocentric spatial memory.

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“…The layer organization of the three separated fields belonging to the periallocortex will be addressed in this review for its structural relevance and functional meaning in spatial navigation and memory. The connectional relationship of the different layers with other brain centers will be briefly addressed in this review (for more details see Insausti et al, 2017 ).…”

Section: Introduction and Historical Accountmentioning

confidence: 99%

The Human Periallocortex: Layer Pattern in Presubiculum, Parasubiculum and Entorhinal Cortex. A Review

et al. 2017

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The cortical mantle is not homogeneous, so that three types of cortex can be distinguished: allocortex, periallocortex and isocortex. The main distinction among those three types is based on morphological differences, in particular the number of layers, overall organization, appearance, etc., as well as its connectivity. Additionally, in the phylogenetic scale, this classification is conserved among different mammals. The most primitive and simple cortex is the allocortex, which is characterized by the presence of three layers, with one cellular main layer; it is continued by the periallocortex, which presents six layers, although with enough differences in the layer pattern to separate three different fields: presubiculum (PrS), parasubiculum (PaS), and entorhinal cortex (EC). The closest part to the allocortex (represented by the subiculum) is the PrS, which shows outer (layers I–III) and inner (V–VI) principal layers (lamina principalis externa and lamina principalis interna), both separated by a cell poor band, parallel to the pial surface (layer IV or lamina dissecans). This layer organization is present throughout the anterior-posterior axis. The PaS continues the PrS, but its rostrocaudal extent is shorter than the PrS. The organization of the PaS shows the layer pattern more clearly than in the PrS. Up to six layers are recognizable in the PaS, with layer IV as lamina dissecans between superficial (layers I–III) and deep (V–VI) layers, as in the PrS. The EC presents even more clearly the layer pattern along both mediolateral and rostrocaudal extent. The layer pattern is a thick layer I, layer II in islands, layer III medium pyramids, layer IV as lamina dissecans (not present throughout the EC extent), layer V with dark and big pyramids and a multiform layer VI. The EC borders laterally the proisocortex (incomplete type of isocortex). Variations in the appearance of its layers justify the distinction of subfields in the EC, in particular in human and nonhuman primates. EC layers are not similar to those in the neocortex. The transition between the periallocortical EC and isocortex is not sharp, so that the proisocortex forms an intervening cortex, which fills the gap between the periallocortex and the isocortex.

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The Nonhuman Primate Hippocampus: Neuroanatomy and Patterns of Cortical Connectivity

Cited by 12 publications

References 133 publications

Causal Discovery of Feedback Networks with Functional Magnetic Resonance Imaging

Causal Discovery of Feedback Networks with Functional Magnetic Resonance Imaging

Nonnavigational spatial memory performance is unaffected by hippocampal damage in monkeys

The Human Periallocortex: Layer Pattern in Presubiculum, Parasubiculum and Entorhinal Cortex. A Review

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