Exam III short answer

• Briefly describe Hebb's Rule

  It states that when a presynaptic neuron repeatedly participates in firing a postsynaptic neuron, the strength of the synaptic connection between them increases. This is often summarized as “neurons that fire together, wire together.”
• Briefly explain the difference between E-LTP and L-LTP. What are the cellular events that differentiate them?

  E-LTP lasts for 1-3 hours and results from the modification of existing proteins and receptors at the synapse.L-LTP lasts for several hours to days and requires gene transcription, new protein synthesis, and the growth of new synaptic connections.The primary cellular events differentiating E-LTP and L-LTP are the involvement of new protein synthesis and structural changes in L-LTP, whereas E-LTP mainly relies on the modification of existing proteins and receptors.
• On an average neuron with a dendritic tree and a single un-branching axon, an action potential is initiated on the soma by a large sudden depolarization. Where does the action potential travel?

  Once initiated, the action potential propagates towards the dendrites and the axon.Dendrites have a lower density of voltage-gated sodium channels, limiting the regenerative propagation of action potentials.The action potential travels a significant distance along the axon, enabling the release of neurotransmitters at synapses
• What must be true about a mechanism for plasticity for it to be modeled by the binomial distribution?

  The probability of success or failure must remain constant across all trials.
• When studying the mechanism of hippocampal plasticity, what is commonly used for an induction protocol to ensure that LTP is induced?

  Post tetanic potentiation
• Classical conditioning in Aplysia

  Involves a neutral stimulus (conditioned stimulus) and a reinforcing stimulus (unconditioned stimulus) eliciting a natural reflex response (unconditioned response)
• Classical Conditioning in Aplysia

  1. Baseline response

  2. Acquisition (pairing)

  3. Conditioned response
• Classical Conditioning in Aplysia

  • Sensory neuron action potential precedes shock for calmodulin to be activated, activating facilitated interneuron and serotonin release
  • Action potential in sensory neurons cause more CA2+ to enter the cell, leading to Calmodulin activation and Adenylyl cyclase, enhancing AP and bigger PKA
  • Adenylyl Cyclase is a coincidence detector
  • Calmodulin, associated with Adenylyl cyclase, enhances Action potential and bigger PKA activation
  • MAP K inhibits CREB 2 and activates CREB 1, directing gene transcription and PKA activation