text: *Orexins (-A and -B) are involved in a number of cognitive processes, including appetite, arousal, and reward, among many others.
  *Neurohypophysial hormones:
  **Arginine-vasopressin
  **Oxytocin regulates social cognition (e.g., trust and pair-bonding) and modulates maternal behavior.
  *Endogenous opioids:
  **Dynorphins
  **Endorphins
  **Endomorphins
  **Enkephalins
  * Neurotrophic factors are biomolecules – nearly all of which are peptides or small proteins – that support the growth, survival, and differentiation of both developing and mature neurons. Examples of notable neurotrophic factors include:
  ** Insulin-like growth factor-1 (IGF-1)
  ** Glial cell line-derived neurotrophic factor (GDNF)
  ** Vascular endothelial growth factor (VEGF)
  ** Brain-derived neurotrophic factor (BDNF)
  ** Nerve growth factor
  ** Neurotrophin-3
  ** Neurotrophin-4
  ** Ephrins
  ** Neuregulins