PSY2061 Lecture Notes - Lecture 7: Lewy Body, Basal Ganglia, Granular Material
1 Jun 2018
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Lecture 7 continued
Neuroplastic responses to Nervous System Damage:
•degeneration
•regeneration
•reorganisation, recovery
The Brain’s neuroplastic response
•The brain can reorganise it self based not only on experience but also after damage
•Neurodegenerative disorders are characterised by progressive cell loss in various brain
regions
•This can differ across disorders:!
- HD: degeneration in caudate & putamen (hyperkinetic)!
- PD: degeneration of neurones in substantial nigra (hypokinetic movement disorder)
Neural degeneration in PD
•Dopaminergic cell loss in subtantia nigra (which projects to the striatum) with formation
of lewy bodies
•Lewy bodies are the most characteristic pathological marker of PD and are laminated
inclusions in neurones still remaining
•They poses a dense core of granular material, with the main body compromised of ring
like filaments, intermingled with degenerating organelles
Neural degeneration in HD
•Striatum receives excitatory glutamatergic input from cortex
•In HD there is excessive excitatory glutamatergic input from cortex to Basal Ganglia
•This leads to over stimulation of glutamate receptors in the striatum and thus excessive
calcium influx, leading to neurotoxicity
•This causes loss of GABA neurones with a consequent imbalance of DAergic system,
GABAergic & cholinergic stratal neurones
Neural reorganisation
-There can be strengthening of existing connections (maybe due to release of inhibition)
and establisment of new connections
-Recovery of function does occur due to compensation
-Recovery may be due to cognitive reserve
-With appropriate rehabilitation and training functions may be regained
-Role of neurogenesis is brain recovery
Document Summary
Neuroplastic responses to nervous system damage: degeneration, regeneration, reorganisation, recovery. The brain"s neuroplastic response: the brain can reorganise it self based not only on experience but also after damage, neurodegenerative disorders are characterised by progressive cell loss in various brain regions, this can differ across disorders: Hd: degeneration in caudate & putamen (hyperkinetic) Pd: degeneration of neurones in substantial nigra (hypokinetic movement disorder) There can be strengthening of existing connections (maybe due to release of inhibition) and establisment of new connections. Recovery of function does occur due to compensation. Recovery may be due to cognitive reserve. With appropriate rehabilitation and training functions may be regained. There are factors that may offer protection against cognitive decline and dementia. Increased levels of physical and cognitive activity has been shown to signi cantly improve memory and other cognitive functions in healthy individuals and in clinical populations. 6 weeks of motor training with a balance board.
