13.8 Neuron Organization and Processing

• Neurons are the basic building blocks of the NS. The billions of neurons within the CNS are organized into a much smaller number of neuronal pools.
• Neuronal pool is group of interconnected neurons with specific functions
• Neuronal pools defined on basis of function rather than anatomy
• Neuronal pools can be both in brain and spinal cord
• Each neuronal pool has limited number of input sources and output destinations
• Pool may contain both excitatory and inhibitory neurons
• Basic wiring pattern in neuronal pool is neural circuit, which can do one of…

  • Divergence 
  • Convergence 
  • Serial processing  
  • Parallel processing  
  • Reverberation  
• • Divergence is spread of info from one neuron/pool to several 
  • Convergence is several neurons synapse on same postsynaptic neuron 
  • Serial processing relays info in sequence from one neuron/pool to another 
  • Parallel processing occurs when several neurons/pools are processing the same info at one time 
  • Reverberation uses positive feedback
• Distinguish between a neuronal pool whose function is divergence and a neuronal pool whose function is convergence.

  Divergence is the spread of information from one neuron to several neurons or from one pool to multiple pools. Convergence occurs when several neurons synapse on the same postsynaptic neuron, or several neuronal pools synapse on one neuronal pool.