Chapter 2 provides a review of intra and extracelluar components of neurons and the associated functions of each component. Development of the action potential is discussed, including concepts such as electrostatic pressure, diffusion, depolarization, and hyperpolarization. The process of neurotransmission is explained with respect to exocytosis, pinocytosis, and endocytosis. Information regarding presynaptic receptors, including transporter proteins, heteroreceptors, and autoreceptors is presented along with information concerning postsynaptic receptors (ionotropic, metabotropic). Specific transmitter substances are discussed, including transmitter gases and large and small molecule transmitters. The chapter concludes with a discussion of psychopharmacology, including pharmacokinetics, agonists and antagonists, and information concerning specific medications, including antianxiety, antipsychotic, and antidepressant medications along with mood stabilizers and psychostimulants.