Description
'I had the good fortune to behold for the first time that fantastic ending of the growing axon. In my sections of the spinal cord of the three day chick embryo, this ending appeared as a concentration of protoplasm of conical form, endowed with amoeboid movements. It could be compared with a living battering ram, soft and flexible, which advances, pushing aside mechanically the obstacles which it finds in its path, until it reaches the region of its peripheral termination. This curious terminal club, I christened the growth cone.' (Santiago Ramón y Cajal, Recollections of My Life, 1937). In Neuronal Growth Cones, Phillip Gordon-Weeks presents the molecular biology of the behavior of growth cones. The book covers the basic morphology and behavior of growth cones, motility and neurite extension via the growth cone cytoskeleton, pathfinding, intracellular signalling, and synaptogenesis. It is the first detailed, critical analysis of all aspects of growth cone biology.
Chapter
Factors influencing growth cone shape
Developmental age and type of substratum
Growth cone collapse/contact inhibition
Leader (pioneer) and follower growth cones
Appearance under the electron microscope: organelles of the growth cone
Membrane-bounded organelles
Axonal versus dendritic growth cones
2 Motility and Neurite Extension: The Growth Cone Cytoskeleton
Organisation of the growth cone cytoskeleton
Microtubule organisation in neurites and growth cones
Neurite extension and microtubule dynamics
Location of microtubule assembly
Direct visualisation of microtubule dynamics
Post-translational modifications of tubulin
Assembly competent tubulin in growth cones
A model for the organisation of microtubules in neuritis and growth cones
A role for microtubules in growth cone pathfinding
Microtubule-associated proteins
Microfilament organisation in neurites and growth cones
Growth cone motility and actin filament dynamics
Do growth cones 'push' or 'pull'?
Differential adhesivity and growth cone pathfinding
Neurite extension and surface membrane growth
Membrane recycling in growth cones
Decision regions and pathfinding
Suitable animals and appropriate techniques
Pathfinding is a property of growth cones
How can guidance cues be identified?
Extracellular matrix molecules
Laminin receptors: integrins
Do extracellular matrix molecules have permissive or instructive roles in pathfinding?
Neural cell adhesion molecule and the immunoglobulin superfamily
The labelled pathways hypothesis
Molecules mediating growth cone-cell surface interactions in invertebrates
Growth cone collapse and retraction
Collapsin/semaphorin receptors
Eph receptors and their ligands (ephrins)
Chemotropic (diffusible) factors
Can growth cones detect chemical gradients and with what steepness?
Demonstration of chemotropic factors in vitro
Molecular characterisation of chemotropic factors
Netrins and their receptors
4 Intracellular Signalling in Growth Cones
Calcium is implicated in neurite growth
The calcium 'set-point' hypothesis
Calcium regulation in growth cones
Do changes in growth cone calcium regulate pathfinding events?
Physiological agents affecting growth cone calcium levels
Down-stream targets for calcium in growth cones
Growth cone calcium concentration and the cytoskeleton
Growth-associated protein 43
Widespread expresssion of GAP-43 in the developing nervous system
GAP-43 is a calmodulin and actin-binding phosphoprotein
GAP-43 regulates phosphatidylinositol-4-phosphate kinase and G protein activity
Non-receptor tyrosine kinases and phosphatases
Heterotrimeric G proteins, small GTP-binding proteins and GTPases
Rho subgroup of the Ras superfamily
Morphological differentiation of synapses
Acquisition of synaptic properties by growth cones
Neurotransmitter release from growth cones
Neurotransmitter storage in growth cones
Neurotransmitter receptors
Molecular mechanisms underlying synaptogenesis at the neuromuscular junction
Motoneuron growth cones release factors that induce synaptogenesis
Agrin induces neurotransmitter receptor aggregation at the synapse