Question about neural connections.

Richard Norman rsnorman at mediaone.net
Thu Feb 17 12:04:54 EST 2000

Actually, a single neuron does not have up to 10,000 dendrites, but it may
have many thousands of synaptic inputs impinging on its dendrites.

An axon typically branches and these branches can spread even more widely
than the dendritic branches.  So one axon can form synaptic contacts on
thousands of other cells.

The fact that one cell receives input from so many other cells is called
"convergence", while the fact that one cell can send its output to so many
other cells is called "divergence".  The enormous scope of both of these
factors contributes to the very powerful information processing ability of
the neuron.

Laughter, like many other emotional aspects of our behavior, is
useful in shaping our behavior.  See an ongoing thread in this
group on the evolutionary significance of emotions.  Finding
pleasure in unusual juxtapositions contributes to our maintaining
curiosity and exploratory behavior, allowing us to learn a tremendous
amount about our environment.  Finding pleasure in shared humor
helps cement social relationships.

But be careful to note that answers to such evolutionary questions
are purely speculative (including my own) unless someone provides
you with data demonstrating the adaptive significance in well
controlled experiments.

Ev <ev at cs.columbia.edu> wrote in message news:88h0r4$51g$1 at nnrp1.deja.com...
> This may seem silly and obvious but I'm confused. Since every neuron
> can have up to 10,000 dendrites but only 1 axon it seems to me that
> there is a mismatch of inputs and outputs. What am I missing? Can a
> single axon terminal sit on more than 1 dendrite?
> Also, I posed the following question to a newsgroup on evolutionary
> biology but the responses were not very convincing: what is the purpose
> of laughter and why do we have areas in the brain devoted to finding
> things comical and humorous? Can anyone help with this?
> Sent via Deja.com http://www.deja.com/
> Before you buy.

More information about the Neur-sci mailing list

Send comments to us at biosci-help [At] net.bio.net