Neuroplasticity: The Mechanisms of Learning (copy)

Neuroplasticity

The brain’s ability to reorganize itself by forming new neural connections throughout life.

Functional plasticity

Changes in neural activity and signaling without major structural changes; includes synaptic efficacy changes.

Structural plasticity

Anatomical changes in brain circuitry, including synapse formation, dendritic spine remodeling, and neurogenesis.

Synapse

A junction where one neuron communicates with another; two main types are excitatory (increases postsynaptic excitability) and inhibitory (decreases postsynaptic excitability).

Long-Term Potentiation (LTP)

A long-lasting enhancement in synaptic strength following high-frequency stimulation; a key mechanism for learning and memory.

Long-Term Depression (LTD)

A long-lasting decrease in synaptic strength, counterbalancing Long-Term Potentiation (LTP).

Dendritic spine

A tiny protrusion on a dendrite where most excitatory synapses occur; its morphology relates to synaptic strength and memory encoding.

Astrocyte

A type of glial cell that modulates neurotransmission, regulates the extracellular environment, and can coordinate activity across neuron populations.

Microglia

Immune cells of the brain that prune synapses and participate in remodeling during development and learning.

Critical period

A developmental window when the nervous system is particularly receptive to specific environmental stimuli.

Neurogenesis

Birth of new neurons, particularly in the hippocampus and olfactory regions of adult mammals.

Pruning

Elimination of unused synapses (and sometimes neurons) to streamline neural circuits.

Environmental enrichment

A concept where increased environmental complexity promotes neurogenesis and enhances brain health.

Adult neurogenesis

The process by which new neurons are generated in specific regions of the adult brain, most notably the hippocampus.

Physiologic adaptive capacity

How well a person’s physiology can adapt to increased demand or behavioral change in the presence of disease or aging.

Multiple Sclerosis (MS)

An autoimmune disease where the immune system attacks the central nervous system myelin, leading to neurological symptoms.

Long-Term Potentiation (LTP)—Key Steps

The process involving glutamate release, receptor activation, depolarization, and subsequent signaling pathways that strengthen synaptic communication.

Long-Term Depression (LTD) Mechanisms

Involves reduced rate of synaptic vesicle recycling and the potential removal of receptors from the postsynaptic membrane.

Dendritic spine morphology

Variations in the shape of dendritic spines, such as mushroom-shaped, long, and small spines, which may function differently in memory storage.