Week Ten - Neuroplasticity

Question 1

What is Neuroplasticity?

Answer 1

The ability of the NS to respond to stimuli by organising its structure, function and connections

• eg after brain injury
• eg disease

Question 2

What is Hebbs Rule?

Answer 2

Neurons that wire together, fire together

Question 3

Eric Kandel & the Sea Slug

Answer 3

First evidence of how memory formation results from molecular changes

Question 4

Bliss & Lomo (1973) LTP

Answer 4

Formed the basis of molecular neuroplasticity that obeys Hebbian principles. Found LTP in mammalian hippocampal slices

Question 5

What is LTP?

Answer 5

The persistent strengthening of synapses based on recent patterns of activity. Long-lasting increases in the signalling between two neurons.

Question 6

Exercise and Depression relationship with Neurogenesis?

Answer 6

Exercise increase neurogenesis

Depression decreases neurogenesis

Question 7

What is adaptive plasticity?

Answer 7

When associated with a gain in function

Question 8

What is maladaptive plasticity?

Answer 8

Negative consequences such as a loss of function or increased injury.
Can occur in conjunction with adaptive changes.

Question 9

Spinal Cord Injury and Brain Plasticity?

Answer 9

Training induced changes in brain plasticity can occur in the absence of any behavioural change. This suggests that the connection between the limb and brain isn’t working/severed. Potential treatment option would be stem cells.

Question 10

Epilepsy occurring years after cerebral trauma indicates?

Answer 10

Progressive plastic changes in the brain leading to alterations in signalling and disinhibition in non-related areas, leading to seizures.

Question 11

How can we see maladaptive plasticity?

Answer 11

Show that it is related to a change in function/behaviour

- greatest plasticity = greatest movement problem.

Question 12

Treatment during Acute phase

Answer 12

Treatment in the acute phase may be beneficial when done at the site of injury

Question 13

Treatment during Chronic phase?

Answer 13

Chronic pain may occur, central changes in the joint and have maladaptive change to the CNS

Question 14

How to reverse abnormal changes to CNS?

Answer 14

Treat the injury (bottom up) - however its weak

Target the brain (top down) - addresses the pain sensitisation

Question 15

Maladaptive plasticity is seen to occur in response to treatment of what type of disorders?

Answer 15

Neuropsychiatric. Following from antipsychotic drugs eg tardive dyskinesia

Question 16

Addiction and Maladaptive Plasticity?

Answer 16

Maladaptive plasticity can occur in the subcortical reward circuit. Prefrontal regulation of limbic circuits are significantly reduced eg loss of modulation. This leads to drug seeking being under the control of brain regions with little control imposed by neo-cortex. Very resistant to reversal

Question 17

What is Neurodegeneration?

Answer 17

A progressive decline in behaviour and neural function often through a pathogenic process and maladaptive cycle.
Compensatory mechanisms may fail and become pathogenic. eg AD

Question 18

What happens when cochlear implanted are fitted to congenitally deaf children? Study

Answer 18

In the absence of normal stimulation, there is a sensitive period of about 3.5 years during which the auditory system remains maximally plasticity. Remains in some but not all children until age 7. After 7, plasticity is greatly reduced.
Helps decide when to place a cochlear implant.

Question 19

What is Metaplasticity?

Answer 19

The modification of plasticity induction by the previous activity of the same postsynaptic neuronal network

A lasting after-effect of an initial bout of neural activity which changes the state of the participating neurons such that the ability to induce synaptic plasticity in those neurons at a later time is altered.

Question 20

Chronic Pain and addressing approaches?

Answer 20

Chronic pain causes changes to the structure of the brain as well as causing reductions in cognitive ability

1. Target the injury
   - this only addresses the nociceptive signals from the peripheral receptors
   - very weak relationship between the extent of musculoskeletal damage and the extent of pain
2. Target pain centrally
   - address the pain sensitisation