|
|
 |
|
|
Know your neurons: how to classify different types of neurons inthe brain's forest by ferujkll sdff
|
|
|
Know your neurons: how to classify different types of neurons inthe brain's forest by FERUJKLL SDFF
|
|
| Article Posted: 07/17/2012 |
| Article Views: 74 |
| Articles Written: 2023 - MORE ARTICLES FROM THIS AUTHOR |
| Word Count: 778 |
| Article Votes: 0 |
|
Know your neurons: how to classify different types of neurons inthe brain's forest |
|
|
|
|
|
Business,Business News,Business Opportunities
|
|
Researchers also categorize neurons by function. Sensory neuronscollect information from sensory organs from the eyes, nose , tongue and skin, for example. Motor neurons carry signals from the brainand spinal cord to muscles. Interneurons connect one neuron toanother: the long axons of projection interneuons link distantbrain regions; the shorter axons of local interneurons form smallercircuits between neighboring cells. Do these basic classes account for all types of neurons? Well, justabout every neuron in the human nervous system should fall into onethese broad categories but these categories do not capture thetrue diversity of the nervous system.
Not even close. If you reallywant to catalogue neurons in their many forms somewhat like theway scientists have classed living things into families and speciesand subspecies you're going to need a lot more categories.Neurons differ from one another structurally, functionally andgenetically, as well as in how they form connections with othercells. In some ways, it's up to you how far you want to takethis. Some people are content with a few broad categories and donot see a need to identify and categorize every single type ofneuron. Others are fascinated by the differences between cells inthe brain and nervous system, even the subtlest distinctions.
Someare fascinated for practical reasons, because some of thesedifferences help explain, for example, why certain diseases onlyharm a certain population of neurons. Others are motivated by purecuriosity. Since at least the 19th century even before Cajal convinced theleading anatomists of the time that the nervous system was made ofdiscrete cells scientists recognized that not all components ofthe nervous system looked the same and began differentiating thesecomponents by name. In 1840, Adolphe Hannover discovered what todaywe call the ganglion cells of the retina, the light-sensitivetissue at the back of the eye. In 1866, Leopold August Besser namedlarge, densely branching neurons "Purkinje cells" aftertheir discoverer, Czech anatomist Jan Purkyn.
VladimirAlekseyevich Betz discovered the largest cells in the centralnervous system, today known as Betz cells. Cajal tried out variousnames for different kinds of neurons, as well as their tinierfeatures. He called little bumps along the length of dendrites espinas , the Spanish word for thorns. Today, we call them dendritic spines.
So how many different types of neurons have scientists named sofar? To find out, I contacted several neuroscientists whospecialize in cell biology and what you could call neuron taxonomy.Perhaps unsurprisingly, no one has an exact number, but if you count all the types and subtypes in the entirenervous system, the answer is at least in the hundreds . One great resource for exploring the cellular diversity of thenervous system is NeuroMorpho.org , a database of digitally reconstructed neurons that you can browseby species, brain region and cell type. Check out the Cell Types page and you'll encounter descriptive names like cone cell,climbing fiber, crab-like, medium spiny cell, pyramidal cell,chandelier cell and tripolar cell each of which boasts a uniquestructure. 3D models of these neurons pop into view when you mouseover the file names of different reconstructions. Gordon Shepherd of Yale University pointed me to the Neuroscience Lexicon, adatabase that he and his colleagues are building.
Take a look foryourself at their current list of types of neurons . Here's what the Lexicon lists for distinct types of neuronsin the cerebellum, an evolutionarily ancient part of the brain thathelps coordinate movement: Cerebellum Golgi cell Cerebellum Lugaro cell Cerebellum Purkinje cell Cerebellum basket cell Cerebellum candelabrum cell Cerebellum granule cell Cerebellum nucleus reciprocal projections neuron Cerebellum stellate cell Cerebellum unipolar brush cell And that's just one region of the brain. Remember that thehuman brain contains around 100 billion neurons densely packed intothree-pounds of tissue. Consider that the human brain is one of themost complex structures we have ever tried to understand. All thoselayers of fragile, excitable tissue folded upon one another.
Withinthose folds we will surely discover new types of neurons of whichwe have no inkling at present. Next time on Know Your Neurons, we meet the members of the secondbroadest category of nervous system cells the glia! References Bentivoglio, M. Life and Discoveries of Santiago Ramon y Cajal.Nobelprize.org. 1998.nobel_prizes/medicine/laureates/1906/cajal-article.html Costandi, M.
The discovery of the neuron. Neurophilosopy. 2006.neurophilosophy.wordpress.com/2006/08/29/the-discovery-of-the-neuron/ Kandel ER, Schwartz JH, Jessell TM 2000. Principles of Neural Science, 4th ed. McGraw-Hill, New York Mazzarello, P.
A unifying concept: the history of cell theory.Nature Cell Biology 1, E13 – E15 (1999) doi :10.1038/8964 Schoonover, Carl. 2010. Portraits of Mind . Abrams. I am an expert from General Industrial Equipment, usually analyzes all kind of industries situation, such as electric egg cookers , woven sack bags.
Related Articles -
electric egg cookers, woven sack bags,
|
Rate This Article  |
|
|
|
|
|
Do you Agree or Disagree? Have a Comment? POST IT!
| Reader Opinions |
|
|
|
|
|
|
|
|
|
| Author Login |
|
|
 |
Advertiser Login
ADVERTISE HERE NOW!
Limited Time $60 Offer!
90 Days-1.5 Million Views
|
|
TIM FAY
After 60-plus years of living, I am just trying to pass down some of the information that I have lea...more
|
|
|
|
|
LAURA JEEVES
At LeadGenerators, we specialise in content-led Online Marketing Strategies for our clients in the t...more
|
|
|
|
|
ALEX BELSEY
I am the editor of QUAY Magazine, a B2B publication based in the South West of the UK. I am also the...more
|
|
|
|
|
GENE MYERS
Author of four books and two screenplays; frequent magazine contributor. I have four other books "in...more
|
|
|
|
|
SUSAN FRIESEN
Located in the lower mainland of B.C., Susan Friesen is a visionary brand strategist, entrepreneur, ...more
|
|
|
|
|
STEPHEN BYE
Steve Bye is currently a fiction writer, who published his first novel, ‘Looking Forward Through the...more
|
|
|
|
|
SHALINI MITTAL
A postgraduate in Fashion Technology. Shalini is a writer at heart! Writing for her is an expression...more
|
|
|
|
|
ADRIAN JOELE
I have been involved in nutrition and weight management for over 12 years and I like to share my kn...more
|
|
|
|
|
JAMES KENNY
James is a Research Enthusiast that focuses on the understanding of how things work and can be impro...more
|
|
|
|
