Cells of the Nervous System: Synaptic Function, Learning, and Neuroplasticity

Vocabulary flashcards (term and definition) covering synaptic function, neural circuits, learning, and neuroplasticity from the lecture notes.

Synapse

The mechanism for communication between two neurons.

Chemical transmission

Release of neurotransmitter from the presynaptic terminal into the synaptic cleft, where it binds to receptors on the postsynaptic membrane.

Presynaptic terminal

The end of the neuron where neurotransmitter-containing vesicles fuse with the membrane to release transmitter.

Vesicles

Membrane-bound sacs in the presynaptic terminal that store neurotransmitter.

Neurotransmitter

Chemical substance released by neurons to transmit signals across the synapse.

Calcium (Ca2+) entry

Calcium ions enter the presynaptic terminal to trigger vesicle fusion with the membrane.

Exocytosis

Release of neurotransmitter from vesicles into the synaptic cleft.

Postsynaptic membrane

Membrane of the neuron receiving the signal, with receptors for neurotransmitters.

Postsynaptic receptor

Receptor proteins on the postsynaptic membrane that bind neurotransmitter and open ion channels.

Excitatory postsynaptic potential (EPSP)

Depolarizing postsynaptic potential caused by Na+ influx through transmitter-activated receptors.

Inhibitory postsynaptic potential (IPSP)

Hyperpolarizing potential reducing the likelihood of an action potential, often via K+ channels.

Depolarization

Increase in membrane permeability leading toward a less negative (more positive) membrane potential.

Action potential

Rapid electrical impulse fired when the postsynaptic membrane reaches threshold.

Threshold potential

Membrane potential (about -55 mV in notes) that must be reached to trigger an action potential.

Resting membrane potential

Baseline membrane potential (about -70 mV) when the neuron is at rest.

Presynaptic action potential

Action potential arriving at the presynaptic terminal, opening Ca2+ channels.

Hebbian learning

“Neurons that fire together wire together.” Learning principle proposed by Donald Hebb.

Neural circuit

An axonal network connecting thousands of neurons; learning strengthens connections.

Synaptic pruning

Selective elimination or weakening of unused synapses during development and learning.

Neuroplasticity

Brain's ability to change at the cellular level and reorganize synaptic pathways; can involve cortical reorganization.

Acquired brain damage

Brain injury obtained after birth with potential rehabilitation and reorganization.

Cortical reorganization

Reassignment of brain activity to different cortical areas following injury or learning.

Habituation

Decreased neural response to a stimulus over time or when pain stops.

Pain intensity

Pain level related to how frequently neurons fire and how many neurons are firing.