Classics in Neuroscience: Axonal Growth Cone and Signaling Molecules

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What was the outcome of the experiments conducted by Shorey and Detwiler in the early 20th century?

Understanding of embryonic development process

Characterization of neurotrophic and neurotrophic action

Identification of the role of muscle tissues in nerve cell sustenance (correct)

Discovery of NGF protein

What was the significant finding of Hamburger and Rita Levi-Montalcini's 1949 study?

Characterization of muscle tissue influence on nerve cell sustenance

Discovery of NGF protein

Identification of neurotrophic and neurotrophic action

Observation of naturally occurring nerve cell death during embryonic development (correct)

What was the contribution of Levi-Montalcini's work in the discovery of NGF?

Discovery of neurotrophic and neurotrophic action

Biochemical identification of NGF protein

Characterization of embryonic development process

Development of tissue culture assays for assessing growth factor levels (correct)

What is the term introduced by Wilhelm His to describe the branched extensions of neurons?

Dendrites Signup and view all the answers

What was the significance of NGF in the field of neuroscience?

It marked the advent of trophic factors controlling neuron targeting and survival Signup and view all the answers

What is the primary function of the axonal growth cone?

To establish contact with target cells Signup and view all the answers

What was the outcome of Cohen's biochemical analysis of tumor extracts?

Biochemical identification of NGF protein Signup and view all the answers

What is the difference between the approaches of His and Ramón y Cajal, and Ross Harrison?

The traditional histological approach vs. the experimental histological approach Signup and view all the answers

What is the primary focus of the class in terms of organizing connections?

Contact Guidance Theory Signup and view all the answers

What was the primary goal of Ross Harrison's experiment on axon formation?

To address misconceptions about axon formation Signup and view all the answers

What was the outcome of Bueker's experiment involving tumor, snake venom, and mouse submaxillary gland?

Discovery of NGF protein Signup and view all the answers

Who is credited with the conceptualization of the axonal growth cone as a specialized structure?

Ramón y Cajal Signup and view all the answers

What was the method used by Ross Harrison in his experiment on axon formation?

Dissecting small pieces of neural tube from frog embryos Signup and view all the answers

What was the key concept behind the chemoaffinity hypothesis proposed by Roger Sperry?

Biochemical 'identification tags' for specific connections Signup and view all the answers

What was the main idea behind Paul Weiss's Resonance Theory?

Muscle contraction coordination and specific patterns of activity Signup and view all the answers

What was the primary experimental approach used by Roger Sperry in the 1940s to test the chemoaffinity hypothesis?

Cutting the optic nerve and rotating the eye in newts, goldfish, and frogs Signup and view all the answers

According to John Langley's experiments, what was observed after cutting preganglionic fibers?

Precise reinnervation Signup and view all the answers

What was the focus of research in the 1980s and 1990s related to the chemoaffinity hypothesis?

The identification of molecular tags and cell surface molecules Signup and view all the answers

What was the conclusion drawn from Paul Weiss's experiments in 1934?

Physical features in the culture dish guide axon alignment Signup and view all the answers

What concept was anticipated by John Langley's speculation on chemical relations and chemotactic guidance?

Nerve Growth Factor (NGF) concepts Signup and view all the answers

What is the key difference between the Contact Guidance Theory and the Resonance Theory?

One relies on chemical signals, while the other relies on physical features Signup and view all the answers

What is the current understanding of the molecules controlling cell-cell interactions in the nervous system?

Multiple signal molecules, including NGF, control cell-cell interactions Signup and view all the answers

What is an example of specific molecules guiding axons to different targets in the nervous system?

Olfactory receptors guiding axons to different glomerular targets Signup and view all the answers

What is the main function of fast axonal transport?

To deliver vesicles and components to the presynaptic active zone Signup and view all the answers

What was the outcome of Paul Weiss's ligature experiment?

Net flow of material from the cell body to the periphery Signup and view all the answers

What was the significance of introducing radioactive tracers in axoplasmic transport studies?

To obtain more precise measurements of axonal transport Signup and view all the answers

What is a challenge in understanding the organization of connections in the nervous system?

Identifying individual cell-specific molecules Signup and view all the answers

What is the approximate speed of fast axonal transport?

400 mm per day Signup and view all the answers

What is the critical role of axonal transport in axonal growth?

To link transport and growth Signup and view all the answers

What is the role of microtubules in axonal transport?

To provide the molecular basis for fast axonal transport Signup and view all the answers