Posted by BarbaraCat on March 27, 2002, at 1:57:03
In reply to BCat: HUH??!!?? » BarbaraCat, posted by Janelle on March 27, 2002, at 1:14:26
Janelle,
Sorry if I confused you. Yes, you are right about the pumps being dedicated to specific transmitters (each neuron is in fact dedicated to a separate transmitter). I had a bit of a brain fart there and wanted to say 'and the various other chemicals, or neurotransmitter-like molecules' also get recycled, but I'm not 100% sure of that. In other words, there are many drugs that mimic the shape of the actual neurochemicals, bind to the receptor and fools the receptor into thinking it's got the real thing. I just don't know if those other chemicals get recycled along with the real ones or not.To answer your question about whether neurons both receive and send, yes, absolutely. That's how neurons, and the entire brain (and stomache, BTW) communicate with each other. The neuron has a cell body, and then has many branches on the receiving end called dendrites, where the receptors are found. The neuron communicates with a web of other neurons by sending an electrical spike down a long arm called the axon. This long arm then branches and each branch terminates in the sending end, or the axonal terminal bulb. This is where the reuptake pumps are found and the neurotransmitters are both stored and released. Each axonal terminal connects (across the synaptic cleft) with the dendrite of another neuron. And recall that each neuron has many many dendrites and axon terminal bulbs like the branches of a tree. Each neuron is communicating with God knows how many other neurons, but it's alot.
The brain is highly electrical. The only way that electric impulses can communicate once they reach that synaptic cleft is by chemical means, hence the neurotransmitters. They get released, float across the synaptic cleft and hopefully find a receptor. Once the neurotransmitters lock into the receptors of ANOTHER neuron's dendrites, an electrical spike is initiated, sending the impulse down the axon to the axonal terminal bulbs and on and on. It's pretty amazing stuff and to think of all that activity, coordination, opening and closing of gates, is mind boggling. It's a wonder that more doesn't go wrong with our wiring. - BCat
poster:BarbaraCat
thread:100140
URL: http://www.dr-bob.org/babble/20020322/msgs/100491.html