1. Studying the Nervous Systems of Humans and Other Animals 1 UNIT I NEURAL SIGNALING 2. Electrical Signals of Nerve Cells 31 3. Voltage-Dependent Membrane Permeability 47 4. Channels and Transporters 69 5. Synaptic Transmission 93 6. Neurotransmitters, Receptors, and Their Effects 129 7. Molecular Signaling within Neurons 165 UNIT II SENSATION AND SENSORY PROCESSING 8. The Somatic Sensory System 189 9. Pain 209 10. Vision: The Eye 229 11. Central Visual Pathways 259 12. The Auditory System 283 13. The Vestibular System 315 14. The Chemical Senses 337 UNIT III MOVEMENT AND ITS CENTRAL CONTROL 15. Lower Motor Neuron Circuits and Motor Control 371 16. Upper Motor Neuron Control of the Brainstem and Spinal Cord 393 17. Modulation of Movement by the Basal Ganglia 417 18. Modulation of Movement by the Cerebellum 435 19. Eye Movements and Sensory Motor Integration 453 20. The Visceral Motor System 469 UNIT IV THE CHANGING BRAIN 21. Early Brain Development 501