Which statement describes the role leptin plays in the onset of puberty?

Which statement describes the role leptin plays in the onset of puberty?

• A. Low levels of leptin increase melatonin production, which triggers puberty
• B. Leptin stimulates production of kisspeptin, which triggers puberty
• C. Leptin is inhibited by cortisol, which can delay puberty
• D. High level of leptin inhibit kisspeptin, thus delaying puberty

Answer: (B)

Leptin serves as a signal of energy reserves to the brain, and its role in puberty is to enable the brain’s reproductive axis to turn on. It does this by promoting kisspeptin production in hypothalamic neurons. Kisspeptin then stimulates GnRH-secreting neurons, triggering pulsatile GnRH release, which drives the pituitary to secrete LH and FSH and leads to the physical and hormonal changes of puberty. So, the idea that leptin stimulates kisspeptin, which in turn triggers puberty, best captures how energy status influences the onset of puberty. The other statements don’t fit this chain: melatonin isn’t the trigger here, cortisol doesn’t directly inhibit leptin to delay puberty in this pathway, and high leptin does not inhibit kisspeptin.

Leptin serves as a signal of energy reserves to the brain, and its role in puberty is to enable the brain’s reproductive axis to turn on. It does this by promoting kisspeptin production in hypothalamic neurons. Kisspeptin then stimulates GnRH-secreting neurons, triggering pulsatile GnRH release, which drives the pituitary to secrete LH and FSH and leads to the physical and hormonal changes of puberty. So, the idea that leptin stimulates kisspeptin, which in turn triggers puberty, best captures how energy status influences the onset of puberty. The other statements don’t fit this chain: melatonin isn’t the trigger here, cortisol doesn’t directly inhibit leptin to delay puberty in this pathway, and high leptin does not inhibit kisspeptin.