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Relationship: 749
Title
Hippocampal anatomy, Altered leads to Hippocampal Physiology, Altered
Upstream event
Downstream event
AOPs Referencing Relationship
| AOP Name | Adjacency | Weight of Evidence | Quantitative Understanding | Point of Contact | Author Status | OECD Status |
|---|---|---|---|---|---|---|
| Inhibition of Thyroperoxidase and Subsequent Adverse Neurodevelopmental Outcomes in Mammals | adjacent | Moderate | Low | Evgeniia Kazymova (send email) | Open for citation & comment | WPHA/WNT Endorsed |
| Sodium Iodide Symporter (NIS) Inhibition and Subsequent Adverse Neurodevelopmental Outcomes in Mammals | adjacent | Moderate | Low | Evgeniia Kazymova (send email) | Under Development: Contributions and Comments Welcome | |
| Thyroid Receptor Antagonism and Subsequent Adverse Neurodevelopmental Outcomes in Mammals | adjacent | Moderate | Low | Evgeniia Kazymova (send email) | Under development: Not open for comment. Do not cite | Under Development |
| Upregulation of Thyroid Hormone Catabolism via Activation of Hepatic Nuclear Receptors, and Subsequent Adverse Neurodevelopmental Outcomes in Mammals | adjacent | Evgeniia Kazymova (send email) | Open for adoption | Under Development |
Taxonomic Applicability
Sex Applicability
| Sex | Evidence |
|---|---|
| Male | High |
| Female | High |
Life Stage Applicability
| Term | Evidence |
|---|---|
| During brain development | High |
The hippocampus is a highly integrated and organized communication and information processing network with millions of interconnections among its constitutive neurons (see Andersen et al, 2006). The neuronal spine is the primary site of action for synaptic interface between neurons. Although difficult to measure due to their small size, large number and variable shapes, changes in the frequency and structure of dendritic spines of hippocampal neurons has dramatic effects on synaptic physiology and plasticity (Harris et al., 1992). Anatomical integrity at a more macro-level is also essential for physiological function. The connectivity of axons emanating from one set of cells that synapse on the dendrites of the receiving cells must be intact for effective communication between neurons to be possible. Synaptogenesis is a critical step for neurons to be integrated into neural networks during development. Changes in the placement of cells within the network due to delays or alterations in neuronal migration, the absence of a full proliferation of dendritic arbors and spine upon which synaptic contacts are made, and the lagging of transmission of electrical impulses due to insufficient myelination will independently and cumulatively impair synaptic function.
| ID | Experimental Design | Species | Upstream Observation | Downstream Observation | Citation (first author, year) | Notes |
|---|
| Title | First Author | Biological Plausibility |
Dose Concordance |
Temporal Concordance |
Incidence Concordance |
|---|
Biological Plausibility
Dose Concordance Evidence
Temporal Concordance Evidence
Incidence Concordance Evidence
Uncertainties and Inconsistencies
There are no inconsistencies in this KER, but there are uncertainties. Although several examples are evident to demonstrate direct linkages between alterations in hippocampal anatomy and disruptions in hippocampal physiology, there is not a common cellular mechanism, anatomical insult, or signature pattern of synaptic impairment that defines a common anatomically driven physiological phenotype. In addition, it is also known that there is an interaction between physiological and anatomical development, where anatomy develops first, and can be ‘reshaped’ by the ongoing maturation of physiological function (e.g., Kutsarova et al., 2017)
Response-response Relationship
Information does not exist to develop quantitative relationships between the KEs in this KER. Papers that utilize knock-out and mutant models have not provided ‘dose-response’ information for anatomy-physiology relationships.
Time-scale
Known Feedforward/Feedback loops influencing this KER
The majority of data in support of this KER is from rodent models. The evolutionary conservation of hippocampal anatomy in mammals, birds, and reptiles (see Hevner, 2016; Streidter, 2015) suggests, with some uncertainty, that this KER is also applicable to multiple species.