Brain Plasticity

• What is functional recovery?

  When a function is regained after brain damage, because it is transferred from the damaged brain region to an undamaged brain region.
• Summarise how nerve impulses are passed from one neuron to the next.

  First, a nerve impulse arrives at the pre-synaptic terminal of the first neuron. This triggers the release of neurotransmitters from the pre-synaptic terminal to the synaptic cleft. The neurotransmitters diffuse across the cleft and bind to post-synaptic receptors. This causes charged particles to enter the post-synaptic neuron. A nerve impulse occurs in the post-synaptic neuron if there is a large enough, positive, change in voltage.
• Normally, a nerve impulse is only triggered in the post-synaptic neuron if multiple EPSPs summate.
• The first mechanism used by the brain to enable functional recovery is synapse strengthening, which is when the likelihood of nerve impulses being transmitted between two neurons increase.
• The second mechanism used by the brain to enable functional recovery is rewiring, which is when new neuron connections are formed between two neurons that aren’t already connected.
• What is a silent synapse?

  A synapse that becomes inactive due to a lack of nerve impulses.
• Neuronal unmasking occurs when silent synapses become active after a period of being inactive.
• Mechanisms of functional recovery

  • Synapse strengthening
  • Rewiring
  • Neuronal unmasking
• Brain plasticity refers to the brain’s ability to change and adapt in response to new experiences, including brain damage. Functional recovery refers to the brain’s ability to change and adapt only after brain damage.
• What is brain plasticity?

  The brain’s ability to change and adapt in response to new experiences or the brain’s ability to change and adapt in response to brain damage.
• Support for Effect of Experience on Brain Plasticity: Maguire's Taxi Driver Study.

  • Maguire took images brains in an MRI scanner to investigate brain plasticity.
  • Maguire performed a quasi experiment.
  • Maguire compared the brains of London taxi drivers to non-taxi drivers.
• What did Maguire find in her Taxi Driver Study?

  • Maguire found a positive correlation between the amount of time participants had spent as a taxi driver and the size of their hippocampus.
  • Maguire concluded that the experience of being a taxi driver led to changes in the brain, like rewiring.
  • Maguire found that taxi drivers have an increased brain volume in the hippocampus.
• Limitations of Maguire's taxi driver study

  • Quasi experiment, so couldn't control participant variables by random allocating participants to groups.
  • Couldn't establish a cause and effect relationship