Week 4 - Autism

Question 1

What is Epigenetics?

Answer 1

Molecular changes that regulate expression of the genome

You already have the genes but not all of them are expressed (available to make protein); epigenetics is what makes the unexpressed genes become expressed e.g. something you eat, an experience you have etc.

Chemical modifications that change the charge
of the histone protein will change how tightly it
associates with DNA and vice versa. Histones are positively charged and DNA are negatively charged so they would prefer to wrap around the histones and keep the genetic information tight - the chemical modifications change the charge of the histone protein and so therefore it changes how tightly it associates with the DNA.

Question 1

Neuropathology of ASD?

Answer 1

• Shorter cerebellum
• Alterations in prefrontal cortex and medial temporal lobe

Increased density of (smaller) neurons in:
- Amygdala
- Cortex (entorhinal)
- Hippocampus

Question 2

Other Causes of ASD?

Answer 2

Phenylketonuria (PKU)
- Phenylalanine inhibits myelination of neurons
- Can result in autistic disorder, learning disorders or psychosocial problems

Sickness of mother during pregnancy (measles/influenza)
Thalidomide

Opioid excess theory: Increased absorption of gluten and casein (dairy).

Serotonergic Dysfunction- High 5-HT during development = Reduced brain serotonin (Hyperserotonaemia)

Question 3

Treatments for ASD

Answer 3

1. Behavioural therapy
2. Dietary constraints (no wheat or dairy, food additives)
3. Pharmacotherapies treat the symptoms not the core aspects of ASD

Question 4

Medications used to help manage symptoms?

Answer 4

Anxiety, Obsessive behaviour: SSRI antidepressants

Aggression: Atypical antipsychotics

Hyperactivity: stimulants used for ADHD

Tics: A2 agonists, antipsychotics

Seizures: Anticonvulsants

Sleep difficulties: melatonin