Hippocampal interlamellar cell–cell connectome that counts

Pak, Sojeong; Jang, Doohyeong; Lee, Jinho; Choi, Gona; Shin, Hongseong; Yang, Sungchil; Yang, Sunggu

doi:10.1002/jcp.30868

Cited by 7 publications

(8 citation statements)

References 102 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The DG and CA3 serve as pivotal information processing hubs within the laminar functional units and are likely to be the main drivers of longitudinal information transmission in the hippocampus. For example, the “CA3‐centric” viewpoint of hippocampal information processing believes that CA3 pyramidal cells project diversely to all hippocampal principal cells (Scharfman, 2007), and many studies have demonstrated the existence of excitatory projecting associational pathways of dentate mossy cells and CA3 pyramidal cells (Gloveli et al, 2005; Pak et al, 2022; Ropireddy et al, 2011).…”

Section: Discussionmentioning

confidence: 99%

“…Across lamellae, longitudinal neuron connections have been discovered along the longitudinal axis. Recent studies have discovered more enriched information flow in the longitudinal plane than the transverse plane (Pak et al, 2022), highlighting the important role of longitudinal organization. We illustrate the lamellae and longitudinal interlamellar connections in the hippocampal body in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

MRI‐based axis‐referenced morphometric model corresponding to lamellar organization for assessing hippocampal atrophy in dementia

Gao,

Ye,

Chen

et al. 2024

Human Brain Mapping

View full text Add to dashboard Cite

Research on the local hippocampal atrophy for early detection of dementia has gained considerable attention. However, accurately quantifying subtle atrophy remains challenging in existing morphological methods due to the lack of consistent biological correspondence with the complex curving regions like the hippocampal head. Thereby, this article presents an innovative axis‐referenced morphometric model (ARMM) that follows the anatomical lamellar organization of the hippocampus, which capture its precise and consistent longitudinal curving trajectory. Specifically, we establish an “axis‐referenced coordinate system” based on a 7 T ex vivo hippocampal atlas following its entire curving longitudinal axis and orthogonal distributed lamellae. We then align individual hippocampi by deforming this template coordinate system to target spaces using boundary‐guided diffeomorphic transformation, while ensuring that the lamellar vectors adhere to the constraint of medial‐axis geometry. Finally, we measure local thickness and curvatures based on the coordinate system and boundary surface reconstructed from vector tips. The morphometric accuracy is evaluated by comparing reconstructed surfaces with those directly extracted from 7 T and 3 T MRI hippocampi. The results demonstrate that ARMM achieves the best performance, particularly in the curving head, surpassing the state‐of‐the‐art morphological models. Additionally, morphological measurements from ARMM exhibit higher discriminatory power in distinguishing early Alzheimer's disease from mild cognitive impairment compared to volume‐based measurements. Overall, the ARMM offers a precise morphometric assessment of hippocampal morphology on MR images, and sheds light on discovering potential image markers for neurodegeneration associated with hippocampal impairment.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

MRI‐based axis‐referenced morphometric model corresponding to lamellar organization for assessing hippocampal atrophy in dementia

Gao,

Ye,

Chen

et al. 2024

Human Brain Mapping

View full text Add to dashboard Cite

show abstract

“…Some evidences to support reasonability of this long axis include that, first, the “CA3-centric” view of hippocampal information processing (Scharfman HE, 2007), which believes that CA3 pyramidal cells projecting diversely to all hippocampal principal cells. Second, many studies demonstrate the existence of excitatory projecting associational pathways of dentate mossy cells and CA3 pyramidal cells (Gloveli T et al, 2005;Pak S,Jang D,Lee J,Choi G,Shin H,Yang S and Yang S, 2022;Ropireddy D et al, 2011). Third, (Gross DW et al, 2020) demonstrates the internal subfield consistency inside hippocampal head.…”

Section: Discussionmentioning

confidence: 99%

“…Second, many studies demonstrate the existence of excitatory projecting associational pathways of dentate mossy cells and CA3 pyramidal cells (Gloveli T et al, 2005;Pak S,Jang D,Lee J,Choi G,Shin H,Yang S and Yang S, 2022;Ropireddy D et al, 2011). Third, demonstrates the internal subfield consistency inside hippocampal head.…”

Section: The Long Axis Of the Hippocampus By Armmmentioning

confidence: 95%

An axis-referenced morphometric model reshaping the hippocampus following its longitudinal organization

Gao

Chen

et al. 2023

Preprint

View full text Add to dashboard Cite

The anterior-posterior gradient of the human hippocampus on coronal slices is commonly referred to as the long axis, which exhibits morphological heterogeneity related to aging and neurodegeneration. However, the actual longitudinal organization follows a laminar architecture along a longitudinal trajectory that terminates not in the absolute anterior tip of the hippocampus, but rather traces the folding uncus. This study proposes an axis-referenced morphometric model (ARMM) to reshape the hippocampus based on its anatomical nature. An atlas of the hippocampus derived from large samples of 7T ex-vivo MRI and histology serves as the prototype of the model. We set up an orthogonal curvilinear coordinate system within the hippocampus, where the internal coordinate lines correspond naturally to longitudinal and transversal axes of the hippocampus through conformal mapping, providing reference when measuring structural features like thickness, width, length, etc. The inverse mapping allows the hippocampal grey matter to unfold onto a two-dimensional rectangle, facilitating point-wise morphological correspondence across individuals. To evaluate the ARMM, we perform a detailed shape representation of the hippocampus from 7T-MRI and compare it with three state-of-the-art shape models. The results show that the ARMM performs best in metrics measuring shape similarity between the reshaped hippocampus and the ground truth, particularly in head folds (Dice=0.9934). Moreover, our examination of ARMM on longitudinal 7T images revealed its ability to capture subtle structural variations due to neurodegeneration. The ARMM offers a unique anatomically motivated morphometric model of hippocampus, and sheds light on discovering new image markers for diseases associated with hippocampal damage.

show abstract

“…In the adult mammalian brain, neurogenesis occurs in restricted regions of the brain: the subgranular zone (SGZ) of the dentate gyrus (DG) in the hippocampus and, the subventricular zone (SVZ) of the lateral ventricles (in mice), which generates neurons migrating to the olfactory bulb, and hypothalamus (in both humans and mice) [3] , [4] , [5] . The hippocampus consists of the Cornu Ammonis fields (CA1, CA2 and CA3) and the DG [6] and is the main region of the brain responsible for memory and learning [7] . The adult neurogenesis in the SGZ is mainly derived from adult neural stem cells (aNSCs) that differentiate into excitatory DG neurons and integrate into the inner circuitry of the hippocampus, connecting mainly to the CA3 pyramidal neuros, mossy cells and hilar interneurons [8] .…”

Section: Introductionmentioning

confidence: 99%