385 CH 2: Synapses

Temporal Summation

Several impulses from one neuron overtime, firing repeatedly to get the next neuron to go, repeated stimuli with a brief time combine their effects

Spatial summation

Impulses from multiple neurons at the same time, combination of effects from the activity of 2+ neurons into one.

EPSP

More likely to fire an action potential, excitatory

IPSP

Decays overtime and distance, hard to fire an action potential, hyperpolarization, inhibitory

Exocytosis

Release of neurotransmitters into the synaptic cleft triggered by calcium

Endocytosis

Bringing of substances into the cell from an external environment.

Degradation

Proteins break down neurotransmitters and the enzymes from receiving neurons break down, degrading or regulation of molecules.

Reuptake

Progressive process that releases neurotransmitters, sucks them back up from synaptic cleft, and reuses and transports back to the terminal. 

Synaptic transmission

An electrical signal is converted into a chemical one to cross between cells at the synapse and generate a signal that excites, inhibit, or modulates activity.

Catecholamines

Neurotransmitters and hormone are essential to the body’s response to stress and physiological situations. 

Ionotropic Effect

Depends on the rapid opening of some kind of gate in the membrane

Metrabotropic Effect

Initiation of a sequence of metabolic reactions that start slower and last longer

Neuropeptide

Chain of amino acid that is released by the cell body, dendrites, or side of axons with gradual effects and spread out receptors.

Neurotransmitter

Released by axon terminal with immediately adjacent receptors with sudden effects. 

Negative Feedback

Receptors that respond to released transmitters by inhibiting further synthesis and release, attempt to restore balance. 

Dopamine Hypothesis

too much dopamine causes hallucinations

Agonist

Binds to receptors in the brain to mimic effects of neurotransmitters that would usually bind to that receptor. 

Antagonist

Opposes the action of the neurotransmitter by binding to the receptor and blocking the neurotransmitter from binding, decreasing or inhibiting effects.