The hypothalamic neurotransmitter kisspeptin plays a central role in puberty and reproduction. Which receptor does kisspeptin act on, and what is its primary effect on GnRH neurons?
- A KISS1R (GPR54); potent stimulator of GnRH pulsatile release from hypothalamic neurons ✓
- B MC4R (melanocortin-4 receptor); modulates GnRH through the energy-sensing pathway
- C GnRHR; acts as a co-agonist potentiating LH surge in mid-cycle
- D LEPR (leptin receptor); bridges energy availability to the gonadal axis
Explanation
Kisspeptin acts on its cognate receptor KISS1R (also called GPR54), which is expressed on GnRH neurons in the arcuate nucleus (KNDy neurons) and the anteroventral periventricular nucleus. Kisspeptin is the most potent endogenous stimulator of GnRH pulsatile secretion; loss-of-function mutations in KISS1R cause idiopathic hypogonadotropic hypogonadism. It is the neural integrator for pubertal onset and mediates estrogen's positive feedback for the LH surge. While leptin (option D) also regulates GnRH, it acts through LEPR indirectly, not directly on GnRH neurons; MC4R (option B) is involved in energy balance, not direct GnRH stimulation.
Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.