Table of Contents
Cellular Basis of Synaptic Plasticity
Cellular Basis of Synaptic Plasticity
History
Hebb’s Postulate Revives Structural Basis of Learning
Overview - Synaptic Changes that could mediate Learning and Memory
New synapses are generated
Existing synapses are modified
New synapses are continuously generated in the brain.
Scope
Diversity in neuronal structure
Hippocampal CA1 Pyramidal Cell
Shaffer Collaterals Synapse on Dendritic spines
Spine Diversity
SYNAPSE WEB
Complexity of Synapse structure
Diversity in Synaptic Structure on Dendritic Spines
Diversity in Presynaptic Connectivity
Presynaptic axons - Connectivity
Presynaptic axons - Connectivity
Presynaptic axons - Connectivity
Complex synaptic interactions in dense Neuropil
MSBs
Complex circuitry revealed with 3D reconstructions
Presynaptic Axon does not determine spine shape
Diversity in the presynaptic vesicle pools
This spine has 241 nondocked vesicles
This spine has 1086 nondocked vesicles
Dimensions of Pre and Postsynaptic Elements are Proportional to one another
Astrocyte - LM
Diversity in Astrocyte support of CA1 Synapses
Mature Dendritic Spines
Hippocampal LTP
Morphological Correlates of LTP - Spine swelling, Neck widening
Morphological Correlates of LTP - Changes in Existing Synapse Structure
Morphological Correlates of LTP - Changes in Synapse Number
WHY NOT SINGLE SECTIONS ANALYSES?
LTP Within Slice Design
LTP Within Slices
Adult Hippocampal Slices
Structural Stability in Synapses 2hr After LTP
LTP in Mature CA1 slices
LTP in Immature Hippocampal Neurons
Hippocampal Dendritic Filopodia at PN6
Two dendritic filopodia synapse on 1 axon at PND6
Immature Dendrite
Postsynaptic Targets during Development
Spinogenesis during Development
Role of activity in filopodial outgrowth
Role of synaptically released glutamate in dendritic spine formation 1
Role of synaptically released glutamate in dendritic spine formation 2
Subset of synapses change connectivity with LTP in organotypic slices 1
Subset of synapses change connectivity with LTP in organotypic slices 2
Subset of synapses change connectivity with LTP in organotypic slices 3
Subset of synapses change connectivity with LTP in organotypic slices 4
Issue in all three of these developmental LTP studies
Caveats
Might LTP preserve newly formed synapses?
|