What is a synapse in psychology?

The synapse is the junction between two neurons and includes all the components necessary for neural communication within the nervous system. It consists of the terminal sacs (or vesicles) located at the axon terminal of the presynaptic neuron, the synaptic gap (or cleft) between the neurons, and the receptor sites on the dendrites of the postsynaptic neuron.

When a neurotransmitter (a chemical messenger) is released from the terminal sacs of the presynaptic neuron, it crosses the synaptic gap and binds with complementary receptors on the postsynaptic neuron. These neurotransmitters can either stimulate or inhibit the activity of the postsynaptic neuron. In doing so, neurotransmission can influence human behaviour.

Whether a neurotransmitter has an excitatory or inhibitory effect depends on the type of neurotransmitter and the specific receptors involved in the synapse.