Zn2+ Modulation of Neurotransmitter Transporters -- Molecular Microfluorometry: Converting Arbitrary Fluorescence Units into Absolute Molecular Concentrations to Study Binding Kinetics and Stoichiometry in Transporters -- Structure/Function Relationships in Serotonin Transporter: New Insights from the Structure of a Bacterial Transporter -- The Importance of Company: Na+ and Cl? Influence Substrate Interaction with SLC6 Transporters and Other Proteins -- Currents in Neurotransmitter Transporters -- Mutational Analysis of Glutamate Transporters -- The Diverse Roles of Vesicular Glutamate Transporter 3 -- Extraneuronal Monoamine Transporter and Organic Cation Transporters 1 and 2: A Review of Transport Efficiency -- The Role of SNARE Proteins in Trafficking and Function of Neurotransmitter Transporters -- Regulation of the Dopamine Transporter by Phosphorylation -- The Dopamine Transporter: A Vigilant Border Control for Psychostimulant Action -- Oligomerization of Neurotransmitter Transporters: A Ticket from the Endoplasmic Reticulum to the Plasma Membrane -- Acute Regulation of Sodium-Dependent Glutamate Transporters: A Focus on Constitutive and Regulated Trafficking -- Regulation and Dysregulation of Glutamate Transporters -- Regulation of Vesicular Monoamine and Glutamate Transporters by Vesicle-Associated Trimeric G Proteins: New Jobs for Long-Known Signal Transduction Molecules -- Human Genetics and Pharmacology of Neurotransmitter Transporters -- ADHD and the Dopamine Transporter: Are There Reasons to Pay Attention? -- Inactivation of 5HT Transport in Mice: Modeling Altered 5HT Homeostasis Implicated in Emotional Dysfunction, Affective Disorders, and Somatic Syndromes -- Lessons from the Knocked-Out Glycine Transporters -- The Norepinephrine Transporter in Physiology and Disease -- The High-Affinity Choline Transporter: A Critical Protein for Sustaining Cholinergic Signaling as Revealed in Studies of Genetically Altered Mice. Neurotransmitter transporters play a pivotal role in synaptic transmission: They function as a reset button and thus de?ne the shape and duration of signal transfer across the synaptic cleft. This statement nowadays appears to be a self-evident truism, but the concept is fairly young: It builds on la- mark studies on "reuptake sites" that were done by Georg Hertting and Julius Axelrod about four decades ago. It is, in this context, a special pleasure that Georg Hertting will celebrate his 80th birthday while this volume goes to press. Initially, the pharmacological and biochemical characterization relied on cl- sical organ and tissue preparation techniques as well as on brain homogenates and platelets. This allowed for the characterization of the substrate speci?cities of individual transport processes and the identi?cation of speci?c inhibitors, and it spurred conjecture about the co-transported ions and the stoichiom- ric coupling of ion in?ux and substrate translocation. The impact on clinical medicine of these efforts is best documented by the continuous proliferation of improved-that is, more selective-antidepressant drugs. A major bre- through was achieved by the puri?cation of a prototypical transporter and by themoreorlessconcomitantisolation of cDNAsthatencoded varioustra- porters some 15 years ago. This marked the advent of a new era: What had been an assorted mix of functional activities that was best de?ned by phar- cological criteria was now attributable and accounted for by de?ned molecular species.