Communications between
Neurons: Synaptic Transmission
,• These communications make it possible for circuits of neurons to gather sensory information,
make plans, and initiate behaviors.
• The primary means of communication between neurons is synaptic transmission—the
transmission of messages from one neuron to another through a synapse.
• chemicals diffuse across the fluid-filled gap
• We will see - postsynaptic potentials—brief depolarizations or hyperpolarizations—that increase
or decrease the rate of firing of the axon of the postsynaptic neuron. Or Alterations in the
membrane potential of a postsynaptic neuron, produced by liberation of neurotransmitter at the synapse.
, • Neurotransmitters exert their effects on cells by attaching to a particular region of a receptor molecule
called the binding site.
• A molecule of the chemical fits into the binding site the way a key fits into a lock:The
shape of the binding site and the shape of the molecule of the neurotransmitter are complementary.
• A chemical that attaches to a binding site is called a ligand, from ligare, “to bind.”
• Neurotransmitters are natural ligands, produced and released by neurons. But other chemicals found in
nature (primarily in plants or in the poisonous venoms of animals) can serve as ligands too. In addition,
artificial ligands can be produced in the laboratory.
Neurons: Synaptic Transmission
,• These communications make it possible for circuits of neurons to gather sensory information,
make plans, and initiate behaviors.
• The primary means of communication between neurons is synaptic transmission—the
transmission of messages from one neuron to another through a synapse.
• chemicals diffuse across the fluid-filled gap
• We will see - postsynaptic potentials—brief depolarizations or hyperpolarizations—that increase
or decrease the rate of firing of the axon of the postsynaptic neuron. Or Alterations in the
membrane potential of a postsynaptic neuron, produced by liberation of neurotransmitter at the synapse.
, • Neurotransmitters exert their effects on cells by attaching to a particular region of a receptor molecule
called the binding site.
• A molecule of the chemical fits into the binding site the way a key fits into a lock:The
shape of the binding site and the shape of the molecule of the neurotransmitter are complementary.
• A chemical that attaches to a binding site is called a ligand, from ligare, “to bind.”
• Neurotransmitters are natural ligands, produced and released by neurons. But other chemicals found in
nature (primarily in plants or in the poisonous venoms of animals) can serve as ligands too. In addition,
artificial ligands can be produced in the laboratory.
