Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!utcsri!utegc!utai!garfield!dalcs!mnetor!uunet!seismo!mcnc!ece-csc!ncrcae!ncr-sd!hp-sdd!hplabs!hp-pcd!uoregon!omepd!mipos3!cpocd2!howard From: howard@cpocd2.UUCP Newsgroups: sci.bio Subject: Re: Octopus....fish, reptile or what? Message-ID: <795@cpocd2.UUCP> Date: Mon, 20-Jul-87 13:41:22 EDT Article-I.D.: cpocd2.795 Posted: Mon Jul 20 13:41:22 1987 Date-Received: Thu, 23-Jul-87 01:42:22 EDT References: <596@xn.LL.MIT.EDU> <2797@phri.UUCP> Reply-To: howard@cpocd2.UUCP (Howard A. Landman) Organization: Intel Corp. ASIC Systems Organization, Chandler AZ Lines: 34 In article <2797@phri.UUCP> lonetto@phri.UUCP (Michael Lonetto) writes: >These animals also have very fast, complex nervous systems, once again >on a par with vertebrate systems. Interestingly, the speed is achieved >without myelination of the nerve axons (the system used in vertebrates). >Instead, the axons are enormous in size (hence the use of the "giant" >squid axon in neurotransmission studies. Even more interesting is that octopus nervous systems use neurohormones which are catecholamines, and are very similar to adrenaline and noradrenaline (also catecholamines). (Nor)Adrenaline is also called (nor)epinephrine. The synthetic pathways are also similar, with about as much difference between different species of octopus as there is between some octopi and humans. (The enzymes involved are different, but the sequence of transformations from phenylalanine -> tyrosine -> ... -> final hormone is nearly identical to human in some species.) Considering that this entire pathway appears to have evolved separately from the mammalian one, the parallel is remarkable. This leads to some curious speculations. For example, it is quite possible that certain catecholamine-like psychotropic drugs (mescaline, MDA, "Ecstasy", amphetamines, ...) would "work" in octopi in a similar manner to the way they "work" in humans. Of course, this would be hard to verify experimentally, since recording the subjective experience of an octopus is a difficult matter. The prospect of dealing with an octopus on a bad trip must also give one pause :-O. If there's any interest, I could dig out my paper on neurohormone biosynthesis, but it's of ~1970 vintage, hence not entirely up to date. -- Howard A. Landman ...!{oliveb,...}!intelca!mipos3!cpocd2!howard howard%cpocd2%sc.intel.com@RELAY.CS.NET "... precisely the opposite of what we now know to be true."