Neuropsychology

• Most common brain cells

  • Neurons
  • Non-neuron cells called glia
• Neurons

  Cells in the brain that send and receive electrical and chemical signals, transmit information to other neurons, muscles, and tissues throughout the body
• What colour are neuron?

  • Cell bodies are often grey
• Glia

  Supporting cells in the brain that communicate through chemical processes
• Glia

  • Some glia insulate neuronal axons and appear white
• Main components of a neuron

  • Dendrites
  • Soma
  • Axon
• Dendrites

  Processes that extend outward from the soma, receive information from thousands of other neurons, main source of input
• Soma

  Cell body, contains nucleus with genetic information, directs protein synthesis, supplies energy and resources
• Axon

  Process that extends far away from the soma, carries action potential to another neuron
• Synapse

  Place where the axon of one neuron comes in close contact to the dendrite of another neuron
• Myelin sheath

  Insulating substance that covers the axon, allows rapid signal and communication between neurons
• Neurotransmitter release and activation

  1. Released from presynaptic terminal button

  2. Travel across synaptic gap

  3. Activate ion channels on postsynaptic spine by binding to receptor sites
• When one neuron fires

  It suppresses the firing of other nearby neurons
• If two neurons in an inhibitory way both fire

  Neither neuron can fire as vigorously as it would otherwise
• White matter

  Composed of the axons of neurons, especially axons covered with myelin sheath
• Axons

  Conduct the electrical signals from the cell, critical to cell communication
• Types of glia cells

  • Oligodendroglia
  • Microglia
  • Astrocytes
• Oligodendroglia

  Form the myelin sheaths by wrapping their dendritic processes around the axons of neurons
• Microglia and astrocytes

  Digest debris of dead neurons, carry nutritional support from blood vessels to the neurons, help regulate the ionic composition of the extracellular fluid
• Glial cells play a vital role in neuronal support, but do not participate in the communication between cells in the same fashion as neurons