INTRINSIC RESTRAINT THEORY

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Central nervous system (CNS) restraint hypothesis of puberty


"In the 1980s, it was found that agonadal subjects had a pattern of changes in gonadotropin concentration. It was  called as intrinsic restraint hypothesis"

  • In addition to sex steroid-mediated negative feedback, a central inhibitory system restrains GnRH release and maintains the prepubertal phase.  
  • At the onset of puberty, the intrinsic CNS restraint is inhibited or is dominated by a stimulatory system. 
  • During the last decades, considerable evidence has been gathered to support this intrinsic restraint hypothesis.


Factors involved in the regulation of gonadotropin-releasing hormone (GnRH) secretion:

Intrinsic restraints:

    1. GABA (Gamma Amino Butyric Acid)

Stimulators:

    1. Glutamate
    2. NPY
    3. Leptin
    4. TNF alpha
     
According to this idea, GnRH secretion is quiescent in childhood because of early neuronal growth, resulting in a restraint of GnRH release. Stimulating factors overcome this restraint and initiate GnRH release again at the onset of puberty.


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