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Relationship: 1495
Title
7α-hydroxypregnenolone synthesis in the brain, decreased leads to Locomotor activity, decreased
Upstream event
Downstream event
AOPs Referencing Relationship
| AOP Name | Adjacency | Weight of Evidence | Quantitative Understanding | Point of Contact | Author Status | OECD Status |
|---|---|---|---|---|---|---|
| Inhibition of CYP7B activity leads to decreased reproductive success via decreased locomotor activity | non-adjacent | High | Moderate | Brendan Ferreri-Hanberry (send email) | Not under active development |
Taxonomic Applicability
Sex Applicability
| Sex | Evidence |
|---|---|
| Male |
Life Stage Applicability
| Term | Evidence |
|---|---|
| Adult, reproductively mature | High |
The presence of 7α-hydroxypregnenolone in the brain is associated with locomotor activity in the salmon and in the male bird and newt. 7α-hydroxypregnenolone is a neurosteroid synthesized from pregnenolone by CYP7B in vertebrates including bird, newt, and fish. When 7α-hydroxypregnenolone concentration increases in the brain (endogenous or exogenous), these animals become active. Oppositely, decreased synthesis of 7α-hydroxypregnenolone limits locomotor activity (Matsunaga et al., 2004).
The importance of 7α-hydroxypregnenolone synthesis is sex dependent in bird and newt. In these species, only male locomotor activity is influenced by the neurosteroid (Matsunaga et al., 2004, Tsutsui et al., 2008). However, both male and female are affected by 7α-hydroxypregnenolone in salmon (haraguchi et al., 2015).
It was known before that locomotor activity in vertebrates fluctuated over a circadian and/or seasonal cycle, although the full mechanism was elusive (Saper et al., 2005). The discovery of 7α-hydroxypregnenolone activity in the brain allowed a better understanding of the locomotor activity regulation in the context of cyclic variations of the environment.
| 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
No inconsistency was reported so far.
- 7α-hydroxypregnenolone injected in the quail brain (0, 10, or 100 ng) induced a dose-dependent increase of locomotor activity (Tsutsui et al., 2008).
- The same experiment was conducted in the newt using 0.1, 0.5, or 1 ng. A dose-dependent increase of locomotor activity was observed (Matsunaga et al., 2004).
- The same experiment was conducted in the chicken using 0.10, or 200 ng. A dose-dependent increase of locomotor activity was observed (Hatori et al., 2011).