What cells conduct electricity?

[gib65]

Neurons obviously conduct electricity, but are they the only cells in the body that do this? Do other cells conduct electricity?

[Mokele]

Well, technically all cells do. They'll all basically sacks of saltwater. Also, as you know, neurons don't conduct electricity the same way a wire does, but instead it would be more accurate to say that a wave of depolarization propagates down the axon. Other than nerves, AFAIK muscle cells are the only animal cell that is electrically excitable. There may be other types in plants; IIRC, flytraps show a voltage change when closing to capture an insect.

 

Mokele

[chuinhen]

As we know that neurones acquire myelin sheath to conduct electric impulse!

 

But why only neurone contains Schcwann cell that grows to form the sheath

wheras

other cells donnot have it ???

[scicop]

As we know that neurones acquire myelin sheath to conduct electric impulse!

 

But why only neurone contains Schcwann cell that grows to form the sheath

wheras

other cells donnot have it ???

 

Neurons do not necessarily need "mylein sheaths" to conduct electric impulses. It certainly increases the speed of current flow (saltatory conduction) by limiting current flow-by increasing membrane resistance-to regions along the process that are very conductive (clustering of voltage gated sodium channels).

 

Neurons do not "contain" schwann cells. Schwann cells are their own individual type cells that wrap around the neuron. There is, however, an inter-dependance between schwann cells and the neuron, one needs the other to survive.

 

However, schwann cells are just a type of GLIAL cell, which more recently has had alot of attention. Glial cells include schwann cells, oligodedrocytes, astrocytes, and microglia and the latter three play an important role in the CNS. They all wrap around neuronal processes and provide structural and "life" support to their associated neurons. With respect to microglia, they actually exert an immunological role in the CNS.

 

In the academic neuroscience world the concept of neuron signaling is being (if not already) changed. Scientist are now receptive to the idea the a a neuronal synpase is not just between pre- and post-synaptic neurons, but also involve their surrounding glia, so the they term the synapse now a "tripartate synapse" VERY RECENT studies have shown that glia can participate in modulating not only neuronal plasticity (i.e.glutamate clearance), but also they can display a form of LTP (long term potentiation), a phenomea linked to memory formation (Science Magazing, 2006 vol 312).

 

Pharmaceutical companies are now very interested in Glia (especially microglia) since they have been linked to the "initiation and/or maintaince" of number of pathologies including neuropathic pain, epilepsey, complications due to stress, certain cancers, psychological disorders such as schizophernia and bipolar disorder, as well as parkinsons and alzheimers disease. In fact, Cold Spring Harbor labs (famous for their research and lecture series/meetings/week long learning seminars) is having a learning seminar next week titled "Glia in Health and Disease" .

 

There is a great article calle the "dark side of glia" published last year in science magazine, by Greg Miller (writer for science mag) , check it out!

[scicop]

darkglia.pdf

 

here's that paper, "dark side of glia"

[chuinhen]

is this a mutualism ?!?!?!

 

What benefit do the 2 cells get ?