2- Neuronal Polarization and Autism

Question 1

Filopodia

Answer 1

Slender cytoplasmic projections that extend beyond the leading edge of lamellipodia in migrating cells

Made of actin

Machinery used for migrating

Question 2

Axon Specification Requires

Answer 2

Microtubules stabilization (tubulin) in shaft

Microfilament stabilization (actin) in growth cone)

Extension of axon driven by extension of actin

Question 3

Neurofilaments

Answer 3

Provide structural support for axons

Regulate axon diameter

Cytoskeletal reorganization
occurs
No neurofilaments found in soma

Question 4

Cell Extrinsic Cues

Answer 4

Neurotrophins

Contact mediated regulators (axon specification)

Activity dependent Ca signals

Question 5

Cell Intrinsic Cues

Answer 5

TF

Cytoskeleton regulators

Question 6

Dendritic Spines

Answer 6

Actin rich protrusions from neuronal dendrites

Form postsynaptic part of excitatory synapses

Major sites of info processing and storage in brain

Question 7

Characteristics of Dendritic Spines in Mature Brain

Answer 7

Less than 3 microm in length

Have spherical head

Head connected to dendrite by thin neck (barrier for organelles, ions)

density fo 1-10 spins/ microm of dendrite

Question 8

Tuberous Sclerosis

Answer 8

Inactivation mutatin in TsC1 or TsC2

Too many spines

Question 9

FXS- Fragile X Syndrome

Answer 9

Abnormal CGG repeats in FMR1 gene

Spines can’t mature

Question 10

Rett Syndrome

Answer 10

Mutation in MECP2 gene

Spines don’t mature

Question 11

Angelman Syndrome

Answer 11

Deletion mutation in UBE3a gene

Not enough spine
Spines don’t mature

Question 12

Down Syndrome

Answer 12

Trisomy of chromosome 21

Not enough spines

Question 13

Autism Spectrum Disorder

Answer 13

Persistant and severe problems in

Social relationships and early communication failure

Idiosyncratic preoccupations and restricted interests

Repetitive behaviours and motor stereotypes

Unusually sensory sensitivties

Resistant to change

Appears early during child development

Groups with pervasive developmental disorders

Question 14

High Functioning Autism (Level 1)

Answer 14

Requires support

Difficulty initiating social interactions

Inflexible behaviour

Difficulty switching activities

Problems with organization

Question 15

Austim (level 2)

Answer 15

Substantial support requires

Deficits with social interactions

Inflexible behaviour

Difficulty/distress with change

Repetitive behaviour

Question 16

Severe Autism (level 3)

Answer 16

Requires very substantial support

Severe deficits with social interactions and communication

Inflexible behaviour

Extreme difficulty with coping with change

Repetitive behaviours interfere with functioning