Chemical Synapses and Neurotransmitters

Flashcards covering key vocabulary related to chemical synapses, neurotransmitters, and their function, including examples of specific neurotransmitters and the effects of drugs like cocaine.

Chemical Synapses

Much more abundant but slower and more precise synapses that use neurotransmitters to send messages.

Neurotransmitters

Chemical signals that diffuse across a synaptic gap to deliver a message from one neuron to another.

Presynaptic Neuron

The cell that is sending the signal in a synapse.

Presynaptic Terminal

A knob-like structure, usually the axon terminal, on the presynaptic neuron that holds synaptic vesicles.

1Synaptic Vesicles

Tiny sacs within the presynaptic terminal, each loaded with thousands of molecules of a given neurotransmitter.

Postsynaptic Neuron

The receiving cell in a synapse, which accepts neurotransmitters in its receptor region.

Synaptic Cleft

A tiny gap between the presynaptic and postsynaptic neurons, across which neurotransmitters diffuse.

Voltage-gated Calcium Channels

Channels in the presynaptic terminal that open when an action potential arrives, releasing calcium into the cytoplasm.

Excitatory Neurotransmitters

Neurotransmitters that depolarize the postsynaptic neuron, making it more likely to fire an action potential.

Inhibitory Neurotransmitters

Neurotransmitters that hyperpolarize the postsynaptic neuron, making it inside more negative and less likely to fire an action potential.

Reuptake

A process where neurotransmitters diffuse back across the synapse and are immediately reabsorbed by the sending neuron.

Serotonin

An inhibitory neurotransmitter that plays an important role in regulating mood, appetite, circadian rhythm, and sleep.

Dopamine

A neurotransmitter that influences emotion and attention, primarily associated with feelings of pleasure.

Norepinephrine

A neurotransmitter that triggers the fight-or-flight response, increasing heart rate and priming muscles.

Cocaine's Effect

Blocks the reuptake of neurotransmitters like dopamine, serotonin, and norepinephrine, leading to their accumulation in the synapse and causing intense euphoric and stimulant effects.