Nobody downloaded yet

Various Mechanisms Used by the Nervous System to Guide Axonal Growth - Essay Example

Comments (0) Cite this document
VARIOUS MECHANISMS USED BY THE NERVOUS SYSTEM TO GUIDE AXONAL GROWTH By Your name Subject Tutor name University Date Various Mechanisms used by the Nervous System to Guide Axonal Growth During the development of the nervous system in the embryonic stage, neurons develop and differentiate from multipotent stem cells away from their target cells (Schatten 2005; Bean 2012)…
Download full paperFile format: .doc, available for editing
GRAB THE BEST PAPER96.2% of users find it useful
Various Mechanisms Used by the Nervous System to Guide Axonal Growth
Read TextPreview

Extract of sample
"Various Mechanisms Used by the Nervous System to Guide Axonal Growth"

Download file to see previous pages Congress 1990). The end of each growing axon is called a growth cone, and functions as a sensing device, interacting with molecules in the environment in order to reach the correct target (Schatten 2005; Bean 2012). The growth cones can be described as expanded “sensory-motile” tips of the growing axons that respond to various attractive and repulsive molecular signals in order to direct and guide axons to their synaptic targets (Myers & Gomez 2011, p. 13585). Thus, axonal growth is guided with the help of guidance cues in the environment. As the nervous system matures, about half the neurons die and only those that have grown properly and are connected to the available synaptic sites survive (U.S. Congress 1990). A study of the mechanisms behind axon guidance to the appropriate targets is necessary in order to better understand the development of the nervous system and to elucidate the formation of the neural network. Mechanisms Underlying Axonal Guidance The guidance of axonal growth is a result of interplay of four types of guidance forces, namely contact attraction, contact repulsion, chemoattraction and chemorepulsion (Tessier-Lavigne & Goodman 1996). ...
At the leading end of the growth cone, actin is polymerized and then moved to the rear for depolymerisation (Bean 2012). This continuous cycling of polymerised actin from the leading end to the rear end and then back to the leading end leads to a “tank-tread” kind of movement that enables the guiding of the growth cone (Bean 2012). Santiago Ramon y Cajal first described the movement of growth cones in 1880 (Zheng 2000; Bean 2012). He described that growth cones move towards their synaptic targets in a circuitous route, thus providing evidence that growth cones themselves have an active role in the guidance process (Bean 2012). However, the first live microscopic observations of growth cones were not made until Ross Harrison developed modern tissue culture (Vitriol & Zheng 2012). Later on, Roger Sperry upon observing the optic nerve lesions of frogs showed that retinotectal axons could regenerate and find their targets, subsequently making precise synaptic connections (Bean 2012). It thus became evident that specific surface markers exist and are used by growth cones for the recognition of targets. This was further demonstrated through studies on zebrafish, drosophila, grasshopper and chick, which showed that guidance of axon growth followed specific and similar pathways in different species, indicating that the mechanisms are conserved across species (Bean 2012). Studies by Gomez et al., Renaudin et al., and Robles and Gomez have shown that point contacts are formed by growth cones using various focal adhesion-related molecules like ?1-integrins, paxillin, FAK and vinculin (Myers & Gomez 2011). Extrinsic Environment-Related Mechanisms Apart from the intrinsic mechanism of growth cone movement, extrinsic ...Download file to see next pagesRead More
Cite this document
  • APA
  • MLA
(“Various Mechanisms Used by the Nervous System to Guide Axonal Growth Essay”, n.d.)
Various Mechanisms Used by the Nervous System to Guide Axonal Growth Essay. Retrieved from https://studentshare.org/biology/1448807-question
(Various Mechanisms Used by the Nervous System to Guide Axonal Growth Essay)
Various Mechanisms Used by the Nervous System to Guide Axonal Growth Essay. https://studentshare.org/biology/1448807-question.
“Various Mechanisms Used by the Nervous System to Guide Axonal Growth Essay”, n.d. https://studentshare.org/biology/1448807-question.
  • Cited: 0 times
Comments (0)
Click to create a comment or rate a document
Automatic Nervous System
Age- related changes and environmental temperature play a significant role in the sympathetic vasoconstriction effect of the autonomic nervous system. Actually, the episodes of fainting when he stands is normally seen in the elderly upon suddenly arising from a reclining or sitting position as long as the average decrease in the blood pressure is just around 20 mmHg of the systolic BP, or 10 mmHg of the diastolic BP, and 10% to 20% increase in heart rate.
3 Pages(750 words)Essay
Central Nervous System Depressent Drugs
The drugs are potent and can have adverse affects to different systems, including the cardiac system, thus leading to death when improperly used. Heath Ledger’s death is an example of the abuse of CNS depressants as his heart stopped when the drugs were misused.
3 Pages(750 words)Essay
The various mechanisms used by the nervous system to guide axonal growth and to determine the survival of neurons
In human beings, the nervous system is consisted of the brain, the spinal cord and the retina (63).1 The peripheral nervous system in human beings is constituted by ganglia and nerves that join each ganglion to the central nervous system and sensory neurons (63).2 Complex neural pathways interconnect these regions.
4 Pages(1000 words)Essay
The Autonomic Nervous System
Therefore, the autonomic nervous system controls the involuntary activities of the smooth muscles and several undertakings o the glands. It forms a component of the peripheral nervous system and can be subdivided into two categories. These include the sympathetic and parasympathetic nervous system. In all these categories are comprised of effector neurons which connect the central nervous system top their effector organs.
7 Pages(1750 words)Essay
Nervous system
353). The cuticle is 5µm thick in young larvae (36 hours, first instar), 25µm in 60-hour-old larvae (second instar), and 40µm in last (third) instar larvae. Maggot behavior is linked to instar development; for example, in the first and second instar the maggots stay close together and feed, but in the third instar, they move away from each other and seek a safe placement for pupal development to occur.
3 Pages(750 words)Essay
Nervous System Anatomy Senses
A. Corresponding to the position of an optic disc, blind spot is a minute portion of the visual field of human eye within the retina. This area cannot detect any images as it does not have any photoreceptors (Dean, Rosen, Mathe,
1 Pages(250 words)Essay
The Sensory Nervous System
The central nervous system comprises of the brain and the spinal cord, whereas the peripheral nervous system includes the spinal nerves and cranial nerves. The PNS essentially acts as a channel to relay sensory impulses
2 Pages(500 words)Essay
Autonomic Nervous System
The nervous system exists in our body to regulate the involuntary actions like heart beat and breathing by transmitting motor impulses to the organs responsible for carrying out those
1 Pages(250 words)Essay
Nervous System Research
The cortical columns or modules are usually more in mammals than they are in invertebrate nervous system where they are compartmentalized during construction. In most cases, during
4 Pages(1000 words)Essay
Human Nervous System
As the author of the essay puts it, the Central Nervous System form the major portion of the nervous system and includes both the brain as well as the spinal cord. Furthermore, some classifications of the Central Nervous System also include retina and the cranial nerves as part of the Central Nervous System.
5 Pages(1250 words)Essay
sponsored ads
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Let us find you another Essay on topic Various Mechanisms Used by the Nervous System to Guide Axonal Growth for FREE!
logo footer
Contact us:
Contact Us Now
FREE Mobile Apps:
  • StudentShare App Store
  • StudentShare Google play
  • About StudentShare
  • Testimonials
  • FAQ
  • Blog
  • Free Essays
  • New Essays
  • Essays
  • Miscellaneous
  • The Newest Essay Topics
  • Index samples by all dates
Join us:
Contact Us