Steven Crane Compiled Section Handouts. Human Behavioral Biology 2012

What is the neuroscience of sex?

How do the sexes differ in the functions of various sex-related brain regions?

• 
  Females:
  
  • 
    Ventromedial hypothalamus - high levels of receptors for estrogen and progesterone, essential for female reproduction
    
  • 
    Midbrain structures: Relays from hypothalamus to the autonomic nervous system in the spine – ex. Lordosis reflex
    
• 
  Males:
  
  • 
    Medial pre-optic hypothalamus: sexual performance, testosterone receptors
    
  • 
    Amygdala: sexual motivation (and aggression…)
    

And what are universal neurobiological aspects of sex?

• 
  Autonomic nervous system used for erections in both sexes– animals can have vascular or muscular.
  
• 
  Orgasm is a shift from parasympathetic to sympathetic nervous stimulation. After orgasm, females on average take longer to return to physiologic baseline than males.
  
• 
  (side note) how does the dopamine system work?
  
  • 
    Something to do with pleasure, reward, anticipation, motivation.
    
  • 
    Active especially in ventral tegmentum and nucleus accumbens (the mesolimbic dopamine circuit)
    
  • 
    Spontaneous reward activates dopamine system.
    
  • 
    But on closer study it's also true that dopamine is about anticipation of a reward and fueling the goal- directed behavior to get the reward.
    
  • 
    Highest dopamine response (fueling reward-seeking behavior) in the context of intermittent rewards:
    

maybe.

• 
  What does dopamine have to do with sex?
  
  • 
    Attractive pictures of women activate these regions in heterosexual men. More attracitve --> more dopamine.
    
  • 
    D1/D2 dopamine receptor situation
    
    • 
      Receptor location
      
      •