Chapter 2: The Developing Brain

Young

________ primate cerebral cortex: connections are greater in number & two times as dense.

Neural Induction

The process by which some cells in the ectoderm differentiate into nervous tissue cells when they receive certain signaling molecules.

Saltatory conduction

The motion of the electrical signal when it jumps from one node to another.

Interconnections

________ happen through the growth of dendrites and axons.

Migration

The process by which neurons move to their proper positions in the brain.

Glia

________ aid in the guidance mechanism for neurons & provide scaffolding for ushering neurons to their destination.

Synapses

Where axons make connections with other cells once they reach their target.

Injury

________ or deprivation of input occurring at specific stages of postnatal life can reshape the underlying circuit development.

Children

________ can learn languages /develop musical ability better than adults.

Ectoderm

The outermost layer of cells in an embryo.

Mesoderm

The middle layer of cells in an embryo.

Apoptosis

________ occurs when the neuron loses a battle with other neurons to receive trophic factors.

Critical periods

________ are characterized by high learning rates.

Cognitive recovery

________ from social deprivation, brain damage, and stroke is the greatest in early life.

Endoderm

The innermost layer of cells in an embryo.

Neurons

________ move from the tubes inner to outer surface.

Myelination

Wrapping around axons by extensions of glial cells.

Dendrites

________ are actively involved in process of initiating contact with axons & recruiting proteins to the postsynaptic side of synapse.

Plasticity

The ability of brain to modify itself and adapt to challenges of environment.

neural network

The ________ is pared back to create a more efficient system.

Interneurons

Neurons that communicate with other neurons.

Proliferation

The rapid reproduction of cells in an organism.

nervous system

The developing ________ must get sensory, movement, or emotional input to mature properly in postnatal life.

Sonic hedgehog

A specific signaling molecule secreted by mesodermal tissue lying beneath the future spinal cord.

process of neural induction

Signaling molecules begin the ________.

growth cone

The binding of signaling molecules with receptors tells the ________ whether to move forward, stop, recoil, or change direction.

Trophic factors

________ produced in limited quantities by target tissues.

Inhibitory neurons

Small neurons with short pathways usually found in CNS.

Loss of vision

________ is actually caused by loss of functional connections between eye and neurons in visual cortex.

Vertebrate netrins

________ guide axons around spinal cord.

proximity of cells

The ________ to the sonic hedgehog secretion site determines what organ they will be.

Apoptosis

Programmed cell death.

Migration

The process by which newly formed neurons travel to their final destination.

synapse

At the ________, the electric signal from the axon is transmitted by neurotransmitters to dendrites of other neuron.

Plasticity

________ is not unique to humans.

Growth Cones

Enlargements on an axons tip that actively explore the environment as they seek out their precise destination.

Signaling molecules

molecules that "turn on" and "turn off" genes

Proliferation

The rapid reproduction of cells in an organism

Migration

The process by which newly formed neurons travel to their final destination

endoderm

The innermost layer of cells in an embryo

ectoderm

The outermost layer of cells in an embryo

mesoderm

The middle layer of cells in an embryo

Neural Induction

The process by which some cells in the ectoderm differentiate into nervous tissue cells when they receive

Sonic hedgehog

A specific signaling molecule secreted by mesodermal tissue lying beneath the future spinal cord

Interneurons

Neurons that communicate with other neurons

Migration

The process by which neurons move to their proper positions in the brain

Inhibitory neurons

Small neurons with short pathways usually found in the CNS

Birth and beyond

the reaction to listening to voices, toy responses, and even the temperature in the room can lead to more connections in neurons

Growth Cones

Enlargements on an axon's tip that actively explore their environment as they seek out their precise destination

Synapses

Where axons make connections with other cells once they reach their target

Myelination

Wrapping around axons by extensions of glial cells

Nodes of Ranvier

Gaps between sections of myelin

Saltatory conduction

The motion of the electrical signal when it jumps from one node to another

Apoptosis

Programmed cell death

E.g

Nerve growth factor is important for sensory neurons

Primates

projections from 2 eyes to brain overlap and then sort to their own territories for each eye

Young primate cerebral cortex

connections are greater in number & two times as dense

Function

judgment, insight, impulse control

Plasticity

The ability of brain to modify itself and adapt to challenges of environment

Experience-expectant plasticity

Developing functions to prepare for the experience to come

Experience-dependent plasticity

Developing the function after the experience has happened