Final answer:
Changes in synaptic efficacy can be a result of changes in depolarization in the postsynaptic potential (PSP) or changes in the presynaptic membrane. Synapses can be strengthened and weakened through synaptic plasticity mechanisms like long-term potentiation (LTP) and long-term depression (LTD).
Step-by-step explanation:
Changes in synaptic efficacy can be a result of changes in depolarization in the postsynaptic potential (PSP) or changes in the presynaptic membrane.
In a chemical synapse, the action potential causes release of neurotransmitter molecules into the synaptic cleft. Through binding to postsynaptic receptors, the neurotransmitter can cause excitatory or inhibitory postsynaptic potentials by depolarizing or hyperpolarizing, respectively, the postsynaptic membrane. In electrical synapses, the action potential is directly communicated to the postsynaptic cell through gap junctions.
Synapses are not static structures and can be strengthened and weakened. Two mechanisms of synaptic plasticity are long-term potentiation (LTP) and long-term depression (LTD).