Agouti-Related Protein 2 Is a New Player in the Teleost Stress Response System.

Agouti-related protein (AgRP) is a hypothalamic regulator of food consumption in mammals. However, AgRP has also been detected in circulation, but a possible endocrine role has not been examined. Zebrafish possess two agrp genes: hypothalamically expressed agrp1, considered functionally equivalent to the single mammalian agrp, and agrp2, which is expressed in pre-optic neurons and uncharacterized pineal gland cells and whose function is not well understood.

The sounds of silence: Barn owl noise in landing and taking off.

A barn owl swooping down generated a quieter, almost silent, noise (acoustic impulses) compared to a louder noise generated by the owl when taking off. These acoustic impulses are at low frequencies which are below the auditory threshold to most rodents. Therefore, rodents are less likely to hear these noises of owl flight.