CAP3 Flashcards
When is the neuronal density in the brain the greatest?
There is a dramatic decrease right before birth and steady decrease to 6 to 15 months and then there are adult values
When is synaptic density the greatest?
Increases before birth until 8 months in the visual cortex; 3 years in the auditory cortex; 1 to 3 years in the prefontal cortex. It then decreases to adult values from the age of 12 to mid-adolescence. The dendritic neuronal architecture matures until late adolescence
How late does myelinization last and where?
3rd decade of life in the intracortical association areas
How much does an infant sleep at birth?
16 hours
How much does an adolescent sleep?
8 hours
What is the percent of time spent in REM sleep at birth and at adulthood?
50% at birth. 20% at age 3 (adult values)
Infants enter REM sleep right away. At what age is sleep onset without REM?
2 1/2 months
Does sensory inhibition increase or decrease with age?
Increase
At what age is REM identified?
28 to 30 weeks (prenatally)
Describe neuronal synapses before and after puberty
Before puberty there is formation and elimination (competitive elimination). After puberty, learning and memory depend on strength of already existing synapses
What is the chromosomal deletion in Williams Syndrome?
7
Wiliams Syndrome is characterized by what clinical presentation?
Intellectual disability, cardiovascular disease, adequate verbal skills, cannot integrate complete picture; play instrument. 1/20,000
What chromosome is affected in Angelman Syndrome?
15 (deletion or two copies)
What are the clinical characteristics of Angelman Syndrome?
Intellectual disability, no speech, large mandible with open mouth expression, hypotonia, motor delays. 1/10,000
What is the clinical presentation of Prader-Willi?
Obesity, temper tantrums, aggression, OCD. 1/10,000
What chromosome is affected in Prader-Willi?
Chromosome 15 q11-q13 deletion from father. Two copies also a cause
What is lissencephaly?
Most common disorder of normal migration of neurons. There are 4 cortical layers instead of the normal 6. There is a smooth cortical surface
What percentage of those with the Fragile X gene are not intellectually impaired?
20%
What gene is affected in Fragile X?
FMR-1
Which repeat defect is there in Fragile X?
CGG (200-1000 vs. 29 found normally)
What is often the first clinical symptom of Rett’s disorder?
Loss of purposeful hand movements
What chromosome is affected in Rett’s?
Xq28
Which protein is implicated in Rett’s?
MECP2 (a mutation leads to inappropriate gene expression and its protein product)
When a young child learns two languages they are represented by a single language center or two?
A single language center. In adults, a new language is represented by a new language center separate from the primary language center