The Brain and Behavior


Neural communications


Neurons are cells that are the building blocks of our major communication system, the nervous system.


They are comprised of a variety of parts


  1. Dendrites
  2. Soma
  3. Axon
    1. Action potential: a brief electrical charge that travels down the axon, rather like a line of dominoes falling, each one tripping the next.
    2. So the nerve cell is much like a battery
    3. Resting potential and refractory period
  4. Myelin Sheath:  a separate glial cells that provides support for the nerve cell.
  5. Terminal branches of the axon leading down the axon to the terminal
  6. Synapse
  7. Synaptic Cleft
  8. Synaptic vesicles
  9. Receptor sites


Neurotransmitters are chemicals that are excreted from the axon terminal and cross the synaptic cleft to the receptor sites on the dendrites.


Excitatory and inhibitory post synaptic potentials, all add up and see if the threshold for firing is determined on the subsequent Axon.




Monoamine family


Dopamine influences movement, learning, attention, and emotions.  Excess activity at dopamine receptors has been linked to schizophrenia.


Serotonin affects mood, hunger, sleep and arousal.  Prozac raises serotonin levels (SRI).


Norepinephrine helps control alertness and arousal.




  1. Best understood
  2. Plays a vital role in learning and memory
  3. Major messenger between motor neurons and a skeletal muscle, when ACH is released into the muscle, the muscle contracts
  4. If ACH is not released a muscle cannot contract
  5. Agonist: a drug that mimics a neurotransmitter at the receptor site (Nicotine)
  6. Antagonist: a drug that blocks a neurotransmitter from being recognized at the receptor site.

Links: : Highly technical : This one is great at explaining agonists, antagonists, and enzymatic breakdown of neurotransmitters in plain language.



The Endorphines


Right Brain/Left Brain :  Cerebral Laterality


Hemispheric Specialization in the Intact Brain


The Endocrine System:  Another Way to Communicate