EXAM 3- Ch 25 Experience-Dependent Plasticity in the Developing Brain

A kitten is deprived of visual stimulation in both eyes for the first 2 months of life. When the cat reaches adulthood, the response of cells in the visual cortex to a light stimulus on the two eyes is recorded. Which outcome would you expect?

Most cells are activated by some degree to stimulation in both eyes.

A kitten is deprived of visual stimulation in one eye for the first 2 months of life. After the cat reaches adulthood, you record from cells in the visual cortex in response to light stimulus on both eyes. Which outcome would you expect?

Most cells are activated only by stimulation to the non-deprived eye

A kitten is deprived of visual stimulation in one eye for the first 2 months of life. After the cat reaches adulthood, you record from different areas of the nervous system the response to direct electrical stimulation to the deprived eye. Where would you expect to see neuronal dysfunction compared to a control cat?

Visual cortex cells

An adult cat is deprived of visual stimulation in one eye for a year. After that time, you record from cells in the visual cortex in response to light stimulus on both eyes. Which outcome would you expect?

Most cells are activated to some degree by stimulation in both eyes.

Critical periods are present for

All of the above

Explain how Ca²⁺ may be involved in Hebbian strengthening of synapses through changes in gene expression.

Calcium activates CaMKII and ERK, which phosphorylate target proteins like AMPA-R. The kinases also translocate to the nucleus and activate transcription factors like CREB, altering gene transcription. Increases in calcium signaling can also modify the cytoskeleton of the cell and alter trafficking of proteins in the cell.

Hebb's postulate

implies that co-activated synaptic contacts will be strengthened, and other synapses weakened.

In which cell type are the retinal waves initiated?

amacrine cells

The images shown are Golgi-stained neurons in the cerebral cortex from individuals at three different ages: birth, 2 years old, and 6 years old. In which choice is each image paired correctly with the subject's age?

left panel: birth; middle panel: 6 years; right panel: 2 years

Studies found that the neural response to an eyelid being sutured shut was

dramatic in kittens but very mild in adult cats

What is a critical period? Give three examples.

A critical period is a time in development during which experience can alter aspects of the nervous system that has highly plastic characteristics. Examples include the learning of proper songs from male tutors in young male zebra finches, imprinting on the mother bird in newly hatched chicks, the development of ocular dominance columns in the visual cortex in mammals, and language learning in humans.

Which characteristic may play a role in the fact that young children can acquire languages with more fluency than adults?

the regions of the brain activated by word-processing tasks in children are different than those activated in adults

Which statement correctly describes a characteristic of a critical period?

neural plasticity does not occur without sensory input