What is the Origin of Lordosis Behavior?

This behavior is a fundamental concept in behavioral endocrinology, first described in ethological studies of mammalian reproductive physiology. The term lordosis itself is derived from the Greek word meaning a bending backward, which accurately describes the posture. Its expression is intrinsically linked to the cyclic fluctuation of ovarian steroid hormones.

What is the Mechanism of Lordosis Behavior?

The behavior is primarily controlled by the action of estradiol on specific neurons within the ventromedial nucleus of the hypothalamus (VMN). Estrogen sensitizes this neural circuit, which normally inhibits the spinal lordosis reflex arc. When the female is in estrus and estrogen levels are high, tactile stimulation from the male triggers the now-uninhibited reflex, causing the back muscles to contract and assume the receptive posture. Progesterone often acts synergistically with estrogen to optimize the timing and intensity of this neuroendocrine-regulated response.

Lordosis Behavior ∞ Area

Lordosis Behavior

Meaning

Lordosis Behavior is the species-typical, highly stereotyped body posture adopted by most non-primate female mammals to signal sexual receptivity and facilitate copulation. The characteristic stance involves a ventral arching of the spine, elevation of the hips, and often a deflection of the tail. This display is a crucial consummatory component of the female reproductive cycle, ensuring successful reproductive outcomes. Its expression is a direct neuroendocrine-behavioral readout of fertility status.