What is a synapse?

A synapse is specifically defined as the junction between two neurons where communication occurs. This process is vital for transmitting signals throughout the nervous system. At a synapse, the sending neuron (presynaptic neuron) releases neurotransmitters, which cross the synaptic cleft and bind to receptors on the receiving neuron (postsynaptic neuron). This complex interaction enables the propagation of nerve impulses and is crucial for various functions such as reflexes, learning, and memory.

Understanding synapses is essential in fields like neurobiology and psychology, as they are foundational to understanding how neurons interact and form networks that underpin brain function. The other options do not accurately capture this specific role or definition.