Outline

5.1 Ramón y Cajal Described Growth Cones and Discerned Their Significance

5.2 In Vitro Approaches Reveal Principles of Axonal Growth and Adhesion

• RESEARCHERS AT WORK Getting a Grip: The Role of Adhesion in Axonal Growth

5.3 Guidance Cues May Be Attractive to One Type of Growth Cone and Repulsive to Others

5.4 Families of Receptors Offer a Multitude of Guidance Cues

5.5 Pioneer Neurons and Guidepost Cells Establish Pathways for Later Axons

5.6 Many Axonal Growth Cones Have to Deal with Crossing the Midline

• RESEARCHERS AT WORK What Makes the Floor Plate so Attractive?

5.7 Motor Neuronal Axons Must Find the Correct Target Muscles

• RESEARCHERS AT WORK Can You Navigate Your Way Home?

5.8 The Axons of Retinal Ganglion Cells Must Reach the Midbrain

• RESEARCHERS AT WORK I’d Rather Walk over Here

5.9 The Corpus Callosum Is Directed across the Midline by a Glial Bridge

• RESEARCHERS AT WORK Glia Can Help Axons Cross a Border