Research suggests this is a behavioral compensation for developmental abnormalities in the routing of nerves in the optic chiasm.Strabismus may also occur in dogs, most often due to imbalanced muscle tone of the muscles surrounding the eye. Some breeds such as the Shar Pei are genetically predisposed to the condition. Treatment may involve surgery or therapy to strengthen the muscles. References
Further reading
Donahue SP, Buckley EG, Christiansen SP, Cruz OA, Dagi LR (August 2014). "Difficult problems: strabismus". Journal of American Association for Pediatric Ophthalmology and Strabismus. 18 (4): e41. doi:10.1016/j.jaapos.2014.07.132. External links
AAO Complex strabismus simulator
UC Davis strabismus simulator
Activation
Carnitine shuttle activation occurs due to a need for fatty acid oxidation which is required for energy production. During vigorous muscle contraction or during fasting, ATP concentration decreases and AMP concentration increases leading to the activation of AMP-activated protein kinase (AMPK). AMPK phosphorylates acetyl-CoA carboxylase, which normally catalyzes malonyl-CoA synthesis. This phosphorylation inhibits acetyl-CoA carboxylase, which in turn lowers the concentration of malonyl-CoA. Lower levels of malonyl-CoA disinhibit carnitine acyltransferase 1, allowing fatty acid import to the mitochondria, ultimately replenishing the supply of ATP. Transcription factors
Peroxisome proliferator-activated receptor alpha (PPARα) is a nuclear receptor that functions as a transcription factor. It acts in muscle, adipose tissue, and liver to turn on a set of genes essential for fatty acid oxidation, including the fatty acid transporters carnitine acyltransferases 1 and 2, the fatty acyl–CoA dehydrogenases for short, medium, long, and very long acyl chains, and related enzymes.PPARα functions as a transcription factor in two cases; as mentioned before when there is an increased demand for energy from fat catabolism, such as during a fast between meals or long-term starvation. Besides that, the transition from fetal to neonatal metabolism in the heart. In the fetus, fuel sources in the heart muscle are glucose and lactate, but in the neonatal heart, fatty acids are the main fuel that require the PPARα to be activated so it is able in turn to activate the genes essential for fatty acid metabolism in this stage.