SMi Source Lesson Obesity: Drug Effects

  • SMi Source lesson Obesity: Drug Effects has the following microlearning topics

  • 1. Normal ARC Function

  • Lesson Obesity: Drug Effects teaches these concepts

  • Obesity, Homeostatic Mechanisms, Normal ARC Function, Control of Energy Homeostasis

    Obesity, Homeostatic Mechanisms, Normal ARC Function, The Weight Control Circuit

    Obesity, Homeostatic Mechanisms, Normal ARC Function, Monoamines

    Obesity, Homeostatic Mechanisms, Normal ARC Function

  • Lesson Obesity: Drug Effects addresses these key points

  • Control of energy homeostasis:

    • Multiple pathways converge in brain to balance energy in with energy out

    Arcuate nucleus:

    • Region of convergence
    • Neural network in the hypothalamus region
    • Integrates hormonal and neural signals to balance food intake with energy expenditure to maintain a stable body weight

    POMC neurons:

    • Activated by anorexigenic or appetite suppressing signals
    • Release α-MSH
      • Activate MC4 receptor
      • Reduce hunger/increase energy expenditure
    • Release beta-endorphin
      • Negative feedback to stop release of α-MSH

    AgRP/NPY neurons:

    • Activated by orexigenic or appetite stimulating signals 
    • Inhibited by appetite suppressing signals 
    • Release neuropeptide Y (NPY) and agouti-related protein (AgRP)
    • Increase hunger/decrease energy expenditure


    • Stimulate neurons to send signals that increase energy expenditure and decrease hunger


    • May occur when circuits of arcuate nucleus are ineffective
      • Resistance to the leptin satiety signal
    • May be treated with therapeutic agents that bypass signal resistance or substances useful in treating addictive disorders
  • Lesson Obesity: Drug Effects introduces and defines these terms

  • α-MSH = Alpha-Melanocyte Stimulating Hormone

    NPY/AgRP = Neuropeptide Y/Agouti-Related

    POMC = Pro-Opiomelanocortin