Lordosis behavior is a sexual response during estrus in certain female animals, such as mice, that consists of a downwards arching of the spine.

Lordosis aids in copulation, as it elevates the female genitals so the male can more easily mate with the female.

In female mice during estrus, the hormone estrogen affects neurons in the ventromedial hypothalamus and the periaqueductal gray of the brain. Sexual stimuli trigger activity in the ventromedial hypothalamus, which sends impulses down axons synapsing with neurons in the periaqueductal gray. These convey an impulse to neurons in the medullary reticular formation which project down the reticulospinal tract and synapse with afferent neurons in the spinal cord (L1-L6) which contract muscles along the spine to exhibit the lordosis posture. Since these afferent neurons are also part of a reflex arc, lordosis can also be triggered reflexively.

See also

• Lordosis