Short communication: Maintained visual performance in birds under high altitude hypoxia.
Comp Biochem Physiol A Mol Integr Physiol
; 296: 111691, 2024 Oct.
Article
in En
| MEDLINE
| ID: mdl-38971399
ABSTRACT
Birds are highly dependent on their vision for orientation and navigation. The avian eye differs from the mammalian eye as the retina is avascular, leaving the inner, highly metabolically active layers with a very long diffusion distance to the oxygen supply. During flight at high altitudes, birds face a decrease in environmental oxygen partial pressure, which leads to a decrease in arterial oxygen levels. Since oxygen perfusion to the retina is already limited in birds, we hypothesize that visual function is impaired by low oxygen availability. However, the visual performance of birds exposed to hypoxia has not been evaluated before. Here, we assess the optomotor response (OMR) in zebra finches under simulated high-altitude hypoxia (10%) and show that the OMR is largely maintained under hypoxia with only a modest reduction in OMR, demonstrating that birds can largely maintain visual function at high altitudes. The method of our study does not provide insight into the mechanisms involved, but our findings suggest that birds have evolved physiological mechanisms for retinal function at low tissue oxygen levels.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Vision, Ocular
/
Finches
/
Altitude
/
Hypoxia
Limits:
Animals
Language:
En
Journal:
Comp Biochem Physiol A Mol Integr Physiol
Journal subject:
BIOLOGIA MOLECULAR
/
FISIOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Dinamarca
Country of publication:
Estados Unidos