4.1 OVERVIEW OF RELEVANT NEUROANATOMY

AND NEUROPHYSIOLOGY

This chapter deals with endogenous messenger molecules (neurotransmitters) within the
human central and peripheral nervous systems (CNS, PNS), their targets, and the drugs that
affect them. Since most of these messengers act on nerve cells (neurons), it is appropriate
to review the anatomy and physiology of the nervous system and to discuss briefly the
neuronal networks that can be manipulated therapeutically. Since the nervous system also
influences homeostasis throughout the entire body, neurotransmitters are ideal messengers
to target when designing drugs within a rational biochemical conceptual framework.
Neurons offer some of the most important targets in drug design (see figure 4.1).

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Messenger Targets for Drug Action I

Neurotransmitters and their receptors

Figure 4.1Neurotransmitters and neurotransmitter receptors as messenger targets: Neurotrans-

mitters affect organs and disease processes throughout the entire body, affording a wealth of targets

for drug design. Drugs based on neurotransmitters are not restricted to brain diseases; they can be

used for the treatment of diseases affecting virtually any organ system within the body.