Refinement of Neuronal Connections Flashcards
What are the effects of a poor environment with a lack of cognitive stimulation?
Reduced synaptic connections - weaker brain neuronal network
Impaired and delayed cognitive development
What are the effects of an enriched environment?
Higher rates of synaptogenesis and more complex dendritic arbors - more synaptic connections - increased brain activity in development
What is the effect of synaptic pruning?
Smaller presynaptic:postsynaptic neuron ratio - more specific connections
Name the 2 models of neural development
Sequential model
Concurrent model
What is the sequential model of neural development?
Formation phase - elimination phase
What is the concurrent model of neural development?
Concurrent elimination and formation
How does neuronal activity affect connections?
Release of growth factors and neurotrophins
Loss of dendritic spines - synapse elimation
Localisation of proteins at synapses
Branching and pruning - synapse refinement
What are neurotrophins?
Proteins that induce survival, development, and function of neurons
What modulates the activity-dependent release of neurotrophins from neurons, and where is this derived from?
Activity-dependent neurotrophic factor (ADNF)
From astrocytes
What are the effect of BDNF on synapses?
Increases RGC axon arborisation and increases synaptobrevin clusters in axon terminal - more synaptic connections form
Define synaptic plasticity
Ability of synapse to strengthen/weaken over time in response to its environment
Define long-term potentiation
Long-lasting enhancement in synaptic strength between 2 neurons - after high frequency stimulation - underlies learning and memory
Define long-term depression
Long-lasting reduction in synaptic strength between 2 neurons - after low frequency stimulation
How does increased neuronal activity affect the localisation of proteins at synapses?
Increases level of TrkB at cell surface
Increases synaptic localisation of AMPARs and NMDARs
Which molecule is responsible for spine morphology changes and what type of molecule is it?
Cadherin - linked to intracellular actin
Cell adhesion molecule
