What are chemical substances released in the brain that facilitate communication between neurons?

The correct choice highlights neurotransmitters as the key chemical substances in the brain responsible for facilitating communication between neurons. Neurotransmitters are molecules that transmit signals across the synaptic cleft from one neuron to another, allowing for the propagation of nerve impulses and the modulation of various physiological functions. Each type of neurotransmitter has specific functions and can influence a wide range of processes in the body, including mood, emotion, and cognition.

In contrast, hormones are chemical messengers produced by glands and released into the bloodstream, where they can affect distant targets, but they do not play a direct role in the rapid signaling between neurons. Enzymes are proteins that catalyze biochemical reactions but do not serve as signaling molecules. Electrolytes, on the other hand, are minerals in the body that carry an electric charge and are essential for various cellular processes, including nerve conduction, but they do not specifically mediate communication between neurons like neurotransmitters do. Understanding the role of neurotransmitters is crucial in the study of psychopathology, as imbalances in neurotransmitter systems can be linked to various mental health disorders.