Lecture 9 Brain Development gpt

Question 1

What is synaptogenesis?

Answer 1

The formation of synapses between neurons, beginning before birth and continuing rapidly through childhood and adolescence.

Question 2

How many synapses form per second at the peak of synaptogenesis?

Answer 2

Around 40,000 per second at week 34 of gestation.

Question 3

Do different brain regions undergo synaptogenesis at the same time?

Answer 3

No, it varies. Sensorimotor cortex finishes earlier than the frontal cortex.

Question 4

What is apoptosis?

Answer 4

Programmed cell death that eliminates neurons which fail to connect effectively with other neurons.

Question 5

What is synaptic pruning?

Answer 5

The elimination of weaker or unused synaptic connections to improve the efficiency of neural networks.

Question 6

What percentage of synapses are pruned away?

Answer 6

Approximately 40% of synapses are eliminated.

Question 7

When does major synaptic pruning occur?

Answer 7

During infancy and adolescence.

Question 8

What part of the brain matures last?

Answer 8

The dorsolateral prefrontal cortex, important for executive functions.

Question 9

When does the dorsolateral prefrontal cortex reach adult size?

Answer 9

After the age of 20, with synaptic pruning continuing into the 30s.

Question 10

What is the impact of reduced synaptic pruning in ASD (autism)?

Answer 10

Increased brain size, higher synaptic density, and increased cortical thickness.

Question 11

What is the impact of excessive pruning in schizophrenia?

Answer 11

Abnormal neural connectivity due to loss of too many synapses during adolescence.

Question 12

What did Austin Riesen’s study on chimps show?

Answer 12

Dark-reared chimps developed retinal and optic nerve atrophy unless exposed to light before 7 months.

Question 13

What does cataract research suggest about human visual development?

Answer 13

There is a critical period for vision; delayed removal can cause lasting impairments.

Question 14

What is cross-modal plasticityin visual deprivation?

Answer 14

Auditory systems recruit visual cortex when visual input is delayed, limiting vision recovery.

Question 15

What is experience-dependent plasticity?

Answer 15

Neural connections are created and reorganized in response to individual-specific experiences.

Question 16

What are effects of enriched environments on animal brains?

Answer 16

More dendritic spines, synapses, thicker cortex, and more glial cells than animals in bare cages.

Question 17

What are the five key processes in brain development?

Answer 17

Neurogenesis, myelination, synaptogenesis, synaptic pruning, and apoptosis.