X-Message-Number: 3902 Date: Fri, 24 Feb 1995 22:12:08 -0800 From: John K Clark <> Subject: SCI.CRYONICS Uploading -----BEGIN PGP SIGNED MESSAGE----- (Eli Brandt) Wrote: >If the simplest part of the brain is, as postulated, an >N-state device, then... that is the simplest part of the brain. You can postulate that 2+2 =5 if you like but that doesn't make it true. >You're saying that it's equivalent to a bunch of 2-state >devices, and going from there to claiming that it actually is >that bunch of devices. Parts always treat other parts as black boxes or they wouldn't be separate parts they'd be subparts of the same part. How a black box does something is not important to other components, what a black box does is important to other components. >They're good enough over the span of a small dendritic tree. >Passive transmission *does* happen in the brain. I never said it didn't, only that it's slow and short range. Incidentally "good enough" is evolution's motto not "perfection". > In fact, it's the predominant sort of dendritic transmission. That of course is the standard view , recently however suspicion has mounted that certain neurons may have active transmission even in their dendrites because passive transmission is just too slow for some things. >I think this isomorphism/identity issue needs to be addresses >if this discussion is to go anywhere. That's what I've been doing for the last 2 months so I'd rather not repeat everything I said in my last 40 posts, but if there's something new you'd like to add, be my guest. >the gap junction. This is not a gated channel at all; it's a >direct ionic coupling. As such, it's much faster than an >electrochemical synapse, Yes, it's much faster than a chemical synapses, but still a LOT slower than electronics because it doesn't use electrons it uses ions and in this case some of them are big, very big, up to 1500 AMU. One AMU is as massive as 1822 electrons. Something that heavy isn't going anyplace in much of a hurry. Also, the gap in a gap junction is 2 to 4 nanometers wide, depending on the neuron that's between a millionth and a billionth it's total length. >but doesn't do much information processing. I agree, their function can't be subtly adjusted as chemical synapses can be. It's not even clear that all neurons have connexons and so form gap junctions. >Conduction in salt water isn't light-speed fast, but I fail >to see how you're going to speed it up much. By junking salt water and their overweight ions and moving to electronics with their fast light electrons. It doesn't matter how a neuron process and transmits information internally if you treat neurons as black boxes, neurons treat their neighbors that way in the brain so we can too. Their is no reason that electrons can't produce the same input output relationship that ions do and do it astronomically faster. John K Clark -----BEGIN PGP SIGNATURE----- Version: 2.6.i iQCzAgUBL07D2303wfSpid95AQHs2gTvabrFbH06PVPFxtnB6uvyvMkU6Sa4u89o ySpxwlYAwu1/9eZVX2OQnfmvQSeA0ttguDPhLxvJGkQcUykmqzrVLLpULCvt9ApF twhH+pwL690wnbyRGP70ZMIXsHHGA2+taBnom9lPTZRbfKS+8xvyRpzhOWltJ0Vn 08F1K2aDebVDSfLhvbeTnaMOawLnpUL375/W9z6ztayAgJkPVcc= =MGwB -----END PGP SIGNATURE----- Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3902