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Evolutionary advantage of Dopamine-Serotonin interactions?

Peter F - for EIMC Internetional Ptd. Lty. fell_spamtrap_in at ozemail.com.au
Tue Apr 26 00:24:57 EST 2005


"hoarse with no name" <no2 at spam.com> wrote in message
news:no2-7600AD.15105616042005 at cnews.newsguy.com...
>
> I have read that serotonin suppresses dopamine levels and vice versa.
> How is this interaction of benefit? What evolutionary advantage derives
> from this?

I hope I am allowed to surmise! ;-)

In relatively simple animals (worms or sea-slugs) neural secretion of
serotonin
has been seen to trigger feeding behavior. (And, dominant and self-assured
animals release and synthesize more serotonin than do lowly ranked
subdominant ones.)

When an animal feeds it ignores (or does not "focus actention" on)
current or past adverse environmental influences.

When the "total situation" (that an animal is in) does not favor
survival by feeding behavior (the animal may not yet be hungry)
but by meeting some other "opportunity type"
evolutionary challenge, such as one that would be met by some
explorative/exploitative (e.g. curiosity expressing)
preoccupation - any of which is primarily pleasurably stressful (or
eustressful) by the way - dopamine may
assist to reinforce the pleasure of (and tending to addict the animal to)
such preoccupations.

Serotonergic focuses of actention such as feeding and similarly safely and
self-assuredly self-promoting
pursuits or preoccupations (on one hand) and (on the other hand)
dopaminergic novelty seeking (explorative/exploitative) behaviors,
are mutually exclusive; So it should not be surprising that (as you write)
"serotonin suppresses dopamine levels and vice versa".

Peter


P.S.
Our different focuses of actention (~= from mainly mental to mainly motor
type preoccupation) are
underpinned by different, functionally (and adaptively) incompatible,
"actention modules" (mainly neural - but not only neural - program
structures).

Incompatible actention modules do mutually as if compete with each other
by way of the brain function organizing principle of "lateral (mutual)
inhibition".
They are also of course nearly always differentially as if 'cheered-on' (and
'booed') by both present and prior (conditioned-in)
environmental features of influence.
And, many have been 'phylogenetically programmed' to have unequal, hence
also innately unequal, synaptic
(and generally neurophysioanatomical) "weights".

Since lifetime opportunities and adversities often overlap (occur at the
same time),
and since some adversities are anything from slowly and imperceptively
traumatizing to rapidly and dramatically so,
and since such experiences normally become stored as correspondingly
insidious memories
(a kind of memories that may be described as "Conditioned-in Chronically
Kept as if precision-Hibernated Hence as if
Unconsciously Remembered, Stressors Effecting Symptoms"), our actention
selecting system (brain/nervous system)
hence our individual psychologies and personalities can in general be seen
to have a functionality that to an important extent
is (and can be conceptualized as) AEVASIVE.

Ambiadvantageously Evolved (that is: in phylogeny proven to be in respect of
the above-mentioned overlap between
positive (opportunity type) environmental evolutionary selection pressures,
and specific hibernation imploring type situations
(a subset of adverse selection pressures) Vital Actention (Selection and/or)
System Involving Various Endorphins (whose known functions
are suitably instructive of the meaning of, as well as supplies an E to,
this acronym).

In persistently adverse and physically unavoidable situations
enogenous opiate-like neuromodulators has the role of assuring that futile
and
self-defeating distressful or flight or fight type focuses of actention
(preoccupation)
does not get energized within the animals "actention selection system" (or
the ASS - a fresh alternative to
"nervous system":-)).





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