Steven Crane Compiled Section Handouts. Human Behavioral Biology 2012

Ventromedial hypothalamus: female sexuality

Medial preoptic area: male sexuality

Suprachiasmatic nucleus: circadian rhythms

Paraventricular nucleus: makes CRH

Arcuate nucleus: location of release into the hyp-pit portal circulation

Lateral hypothalamus: hunger

How do we study the brain (and the limbic system specifically)?

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  Lesion studies like H.M.
  

• Stimulating electrodes (or Transcranial Magnetic Stimulation, Steven's favorite!)

• Recording electrodes (for electrical or chemical recording)

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  Gene expression and other molecular techniques (what NTs are at work?)
  
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  Imaging (anatomy)
  

^o Structural plasticity seen in London taxi cab drivers' hippocampi. Amygdala larger with PTSD.

What caveats do you have to watch out for when trying to infer brain function?

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  Centers vs. fibers of passage
  
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  Behavior doesn't lend itself well to a "center" concept: more distributed in reality
  
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  Ethological perspective is vital: what does the behavior mean for the survival of that animal?
  
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  Individual differences like rank can cause very different outcomes from stimulation: rank in baboons, for example, influences how they respond to a threat yawn
  

What is subliminal presentation? What brain region responds to it?

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  Amygdala is easily activated by stimuli so subtle or quick that you don't consciously recognize them. It then influences the hypothalamus which influences the body.
  
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  Explains anxiety triggers in panic attacks and PTSD that are too subtle to be consciously perceived.
  

How is CRH tied to alertness?

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  When something is different/novel/unexpected the hippocampus recognizes that and alerts the hypothalamus to get CRH moving to stimulate alertness.
  

How do the hippocampus and amygdala mediate fear memories?

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  Amygdala tends to "remember" the specific, most salient fright cue
  
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  Hippocampus tends to "remember" the context, the surroundings
  

How is the limbic system regulated by the peripheral bodily physiology?

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  Called the James-Lange theory of emotion. The body tells the brain what to feel.
  
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  Peripheral physiology influences emotional state.
  

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  Ex: (note from extended notes): administer epinephrine, lie to people about it, and they then interpret their aroused physiology as intensifying whatever emotion was triggered by their social context.
  
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  Ex: holding a pen in the mouth as a frown or a smile influences people's mood.
  
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  Ex: benzodiazepines as muscle relaxants peripherally also decrease anxiety
  
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  Ex: good posture makes you prouder
  

Example Exam Questions

1. 
   In the triune (tri layer) brain concept, the is considered to comprise the third layer. From a functional standpoint, one part of this region, called the is considered by many to be actually part of the , which is considered to be part of the 2nd layer of the brain. (4 pts)
   

Why is that? (2pts)

2. 
   The post synaptic neuron is repeatedly exposed to massive levels of neurotransmitter. Over time, what changes might occur in receptors in the post-synaptic neuron? (1pt).
   

To call the study of chaos "nonlinear science" is like calling zoology "the study of nonelephant animals"
- Stanislaw Ulam in Chaos