Cellular Basis of Behavioural Illness

Question 1

What is catatonia?

Answer 1

Motor immobility as evidenced by catalepsy (including waxy flexibility) or stupor

Excessive motor activity (purposeless, not influenced by external stimuli)

Extreme negativism (motiveless resistance to all instructions or maintenance of a rigid posture against attempts to be moved) or mutism

Peculiarities of voluntary movement as evidenced by posturing, stereotyped movements, prominent mannerisms, or prominent grimacing

Echolalia or echopraxia

Question 2

Which region of the brain is one of the last to show grey matter loss?

Answer 2

Frontal

Question 3

In what order does cortical grey matter thinning occur?

Answer 3

Posterior regions first, prefrontal and lateral temporal later

Question 4

What role do synapses play in schizophrenia?

Answer 4

It is suggested that in schizophrenia and other disorders in childhood and adolescence, there is a problem with synaptic formation or pruning

Question 5

What happens to grey matter in the frontal cortex throughout adolescence?

Answer 5

It is lost

Question 6

What is the final phase of synaptogenesis?

Answer 6

Synaptic pruning

occurs early in sensory cortex

Late in frontal cortex

Question 7

What happens to synaptic spine density of pyramidal cells across development?

Answer 7

Decrease

Dendritic spine density is 2-3 x greater in children compared with adults, and

Begins to decrease during puberty

synaptic overproduction and elimination continues beyond adolescence and throughout 3rd decade, before stabilising

Question 8

What happens to anatomical connectivity during development?

Answer 8

↓Neuronal size

↓ neuronal connections (dendrites & synapses; ↓ connections between thalamus & cortex; ↓ synapsin, ↓ gap43, ↓connexins)

Question 9

What regulates the cell skeleton?

Answer 9

Wnt

Question 10

How are human protoplasmic astrocytes different compared to rodents?

Answer 10

Almost 3-fold greater in diameter

10 fold more abundant GFAP-defined processes

Question 11

What happens to glial density and neuronal size in shizophrenia?

Answer 11

Decreases

Question 12

What happens to neuron size in the DLPFC in schizophrenia?

Answer 12

Decreases (~20%)

Question 13

What is OCD behaviour linked to?

Answer 13

Microglia

Hoxb8 mutants have behaviour similar to OCD, can be rescued by transplantation of wild-type bone marrow

Question 14

What microglia abnormalities are seen in autism?

Answer 14

Dorsolateral prefrontal cortex is a region of peak early overgrowth

Grey and white matter both affected

Enlargement does not persist into late childhood

Question 15

What happens to microglia activity in autism?

Answer 15

Overactivated (amoeboid)

Question 16

What happens to microglial density and volume in autistic DLPFC?

Answer 16

Increases

Question 17

What does the first genetic test for autism look for?

Answer 17

Single nucleotide polymorphisms (SNPs)

Question 18

What did the monozygotic twin who didn’t have autism have in his SNPs?

Answer 18

More protective SNPs!

Therefore, you can have the autism SNPs but protective SNPs also play a role.

Question 19

Which SNP is important for protection against autism?

Answer 19

GRM5