Brain communication & Plasticity

Action potentials

Electrical impulses that allow neurons to communicate, characterized by the all-or-none response.

Threshold of excitation

The level of membrane depolarization that must be reached for an action potential to occur.

Refractory period

The period after an action potential during which a neuron cannot fire another action potential.

Absolute refractory period

The short phase following an action potential during which it is impossible to generate another action potential.

Relative refractory period

A phase during which a neuron can fire again, but requires a stronger than normal stimulus.

Conduction along the axon

The process of action potentials traveling along the axon, depolarizing the membrane as they go.

Myelinated axon

An axon covered with myelin sheath, leading to faster action potential propagation.

Saltatory conduction

A method of action potential propagation in myelinated axons where the signal jumps between nodes of Ranvier.

Neuroplasticity

The brain's ability to change and adapt in response to experience and environment.

Synaptic pruning

The process of eliminating weaker synaptic contacts while strengthening others, crucial for efficient brain function.

Synaptic sprouting

The growth of new synapses as a response to injury or learning.

Hebbian theory

A theory stating that neurons that fire together wire together, facilitating learning and memory.

Long-term potentiation (LTP)

An enduring increase in synaptic strength following high-frequency stimulation of a synapse.

Long-term depression (LTD)

A lasting decrease in synaptic strength following low-frequency stimulation of a synapse.

Glial cells

Non-neuronal cells in the brain that support, nourish, and protect neurons; play roles in neuroplasticity.

Cortical representation

The mapping of sensory input to specific regions of the cerebral cortex.

Maguire et al. (2000)

Study that showed experienced taxi drivers have larger hippocampi than novices, indicating brain changes due to experience.

Pascual-Leone et al.'s Braille readers study

Research showing that Braille readers have an enlarged cortical representation of reading fingers.

Phantom limbs

Sensations, including pain, that appear to come from an amputated limb.

Mirror box therapy

A therapeutic technique that creates visual feedback to alleviate phantom limb pain.

Maladaptive plasticity

Plastic changes in the brain that lead to negative outcomes, such as chronic pain.

Central sensitization

A condition where the nervous system becomes overly sensitive, leading to prolonged pain.

Constraint-induced movement therapy (CIMT)

A recovery therapy that encourages the use of an affected limb while restraining the unaffected limb.

Cortical reorganization

The brain's ability to reorganize itself due to changes in sensory input or injury.

Neural pathways

Connections between neurons that facilitate communication within the nervous system.

Dendritic sprouting

The growth of new dendrites to form connections after neural injury.

Neurotransmitter

Chemicals released by neurons that transmit signals across synapses.

Excitatory post-synaptic potential (EPSP)

A temporary increase in the postsynaptic membrane potential, making it more likely to fire an action potential.

Inhibitory post-synaptic potential (IPSP)

A temporary decrease in the postsynaptic membrane potential, making it less likely to fire an action potential.

Membrane potential

The difference in electrical charge across a neuron's membrane, key to generating action potentials.

Cell body (soma)

The part of a neuron that contains the nucleus and organelles.

Axon

The long, thin part of a neuron that transmits electrical impulses away from the cell body.

Dendrites

Branch-like structures of neurons that receive incoming signals from other neurons.

Neuron

A nerve cell that transmits signals throughout the body.

Sensory neurons

Neurons that carry information from sensory receptors to the central nervous system.

Motor neurons

Neurons that transmit signals from the central nervous system to muscles, facilitating movement.

Interneurons

Neurons that connect sensory and motor neurons within the central nervous system.

Neurogenesis

The process of generating new neurons, which can occur in certain brain regions throughout adulthood.

Cerebral cortex

The outer layer of the brain, responsible for higher-order brain functions such as perception and cognition.

Learning

A process leading to relatively permanent changes in behavior due to experience.

Developmental plasticity

Changes in brain structure and function that occur throughout childhood and adolescence.

Adult neuroplasticity

The capacity for brain plasticity that continues into adulthood and can be influenced by learning and environmental factors.

Functional systems

Organized behavioral and cognitive processes that rely on coordinated brain activity.

Genetic factors

Inherited characteristics that may influence brain plasticity and individual differences.

Environmental influences

External conditions and experiences that can shape brain development and plasticity.

Myelin sheath

The insulating layer surrounding axons that facilitates faster electrical signal conduction.

Axonal injury

Damage to axons that can affect neural transmission and potentially lead to regeneration.

Neural circuits

Networks of interconnected neurons that process specific types of information.

Brain injury

Damage to the brain that can result from trauma, stroke, or disease, often leading to neuroplastic changes.

Structural changes in the brain

Physical alterations in brain architecture due to various factors, including learning and injury.

Cognitive rehabilitation

Therapy aimed at improving cognitive functions that have been impaired by brain injury or disease.

Plasticity during critical periods

The idea that certain experiences have a stronger impact on brain development during specific time frames.

Recovery of function

The process by which the brain adapts after injury, potentially restoring lost functions.