Cellular and Molecular Mechanisms Flashcards
What is cortical plasticity?
Plasticity refers to changes in neural pathways and synapses.
This occurs two ways:
- Pre and post are active simultaneously > synapse strengthens…fired together wired together
- Pre and post are not linked > synapse is weakened…fired out of sync lose their lync.
What is Long Term Potentiation?
LTP occurs when neurons fire together and become wired together.
Usually follows a strong NMDA receptor stimulation followed by a maintained response (LTP).
What is the mechanism of LTP?
- Glut is released and stimulates NMDA receptors
- Influx of Ca through NMDA receptors
- Influx of Ca signals intracellular stores of AMPA receptors
- AMPA receptors are released onto the post-synaptic membrane
- The increased number of receptors are able to maintain the post-synaptic response
Maintenance of the post-synaptic response is your LTP!
What is LTD?
Neurons that fire out of sync lose their link.
- Weak NMDA receptor activation
- Decline in AMPA receptors at post membrane
Which requries protein synthesis, LT or ST memory?
LT!
What is an engram?
The hypothetical physical representation or location of memory in the brain.
What did HEbb postulate?
He thought memory was in a specific region in the brain but then he realized that it mis actually more diffuse and like a cell assembly.
What is a cell assembly?
A group of simultaneously active neurons
The more stimulated an assembly the stronger a memory
What are the brain structures involved in memory formation?
Hippocampus
Parahippocampal cortex
perirhinal cotex
rhinal sulcus
How does ST memory occur molecularly?
NO protein synthesis!
PKA phosphorylates K channels > channels slow down > greater influx Ca this leads to ST memory formation
How is a LT memory formed on a molecular level?
REQUIRES PROTEIN SYNTHESIS
- PKA activates MAPK
- MAPK activates TFS (CREB 2)
- CREB 2 binds to cAMP response elements in nucleus
- Growth/synthesis of receptors to post synaptic membrane.
What does CreB do?
spatial memory
What does CASK do?
regulates CaMKII
What does PKA do
ACts on CREB 2
What gene is related to intelligence?
NPTN: protein coding gene involved in LTP and synaptic plasticity, affects cortical thickness.
Thicker your gray matter smarter you are.
