Glutamate Receptors Flashcards
What is Hebbian Learning?
When an axon of CellA is near enough to excite B and repeatedly or persistently takes part in firing it, some growth processes or metabolic change takes place in one or both cells such that A’s efficiency, as one of the cells firing B, is increased
What are Hebb’s three postulates?
- Hebbian learning
- Cell Assemblies
- Phase Sequences
What is a Cell Assembly?
Groups of neurons which tend to fire together
What is a Phase Sequence?
The sequential activation of sets of Cell Assemblies
What are the types of memory according to McDougall?
- Implicit
* Explicit
What are the types of memory according to Ryle and Bruner?
- Knowing how
* Knowing what
What are the types of memory currently accepted today?
- Declarative
* Non-declarative
What was removed from HM?
The hippocampus on both sides
What is the main excitatory NT in the mammalian CNS?
Glutamate
What is an NMDA receptor involved in?
An NMDA receptor is involved in mechanisms of synaptic plasticity in the mammalian brain
What are the two types of glutamate receptor?
- Ionotropic
* Metabotropic
What are Ionotropic Glutamate receptors?
Ligand-gated ion channels
What are Metabotropic glutamate receptors?
G-protein coupled receptors that act via secondary messenger systems
What is the pharmacological classification of Ionotropic glutamate receptors
• NMDA type receptors
• Non-NMDA type receptors
->AMPA receptors
->Kainate receptors
What are AMPA receptors?
GluR1-4
What are the kainate receptors?
GluR5-7, KA1 and KA2
What are the NMDA receptors?
NMDAR1, NMDAR2A-D
Who isolated GluR1?
Hollmann et al (1989)
What did Hollmann et al discover?
The genetic structure of GluR1
What is the structure of GluR1?
Two proteins:
• 4 transmembrane helices
• 3 transmembrane helices + pore loop
On ionotropic glutamate receptors what is the glutamate binding site formed by?
An N-terminal tail and the extracellular loop linking helices 2 and 3
What forms the channel in an Ionotropic glutamate receptor?
The P-loop between transmembrane helices 1 and 2
What type of ion channels do iGluRs form?
Tetrameric
What are the majority of AMPA receptors in the CNS?
Heteromers containing GluR2
What effect does the presence of GluR2 have on AMPA receptors?
It makes them impermeable to calcium
What do postsynaptic AMPA glutamate receptors mediate?
Postsynaptic depolarisation (due to a net influx of NA+)
What is the role of kainate receptors in synaptic transmission?
They have a modulatory role, both pre-and post synaptically
How did ionotropic glutamate receptors evolve?
They are evolved independently of nicotinic ACh, GABA and glycine channels
