cyble <bmiller at scott.skidmore.edu> wrote:
>i'm afraid that i can't help on this one, but i have an additional
>question: are levels of various neurotransmitters hereditary? in other
>words, have there been any studies suggesting that normal/abnormal
>levels of chemicals like dopamine and serotonin have a genetic basis?
>i'm doing a paper on the hereditary nature of bipolar disorder and
>schizophrenia, and i'm intrigued by this part.
Sorry, can't answer your question but I can add one of my own.
It's always puzzled me why some mental disorders should occur at
all. If a disorder is caused by a deficiency in one or more
neurotransmitters, why doesn't normal cellular metabolizm lead
to a similar repression in neurotransmitter resceptor sites?
Why doesn't the brain addapt to the new level of neurotransmitter?
The basic processes of life are geared toward homeostatic regulation;
genes are constantly switching on and off in response to changes in
the external environment. Can the level of neurotransmitters and
their resceptor sites really be arbitrary and unconnected?
Shouldn't they eventually reach a balance? What is it that
sets the 'normal' levels anyway if it isn't a process of feed-
back regulation? Poisoning of the brain with chemicals such
as alcohol and MDMA do lead to a re-adjustment of resceptor
levels along with a loss in neurotransmitter activity.
What is it about a 'diseased' brain that prevents it from
adjusting its sensitivity to itself? Surely the interesting
thing about neurotransmitter deficiencies is not the loss
of the transmitter but the fact that the sensitivity to the
transmitter is unaffected by its absence. This seems to go
against everything that is known about the biochemistry of
cells which have amazing powers of self regulation.
Could it be that these diseases have causes oposite to the
usual explaination. Perhaps the resceptors for certain
neurotransmitters are over expressed. Maybe its this that
causes a drop in neurotransmitter levels as the brain
attempts to keep itself regulated. Maybe low transmitter
levels are not the cause of disfunction but a _result_
of a more fundamental disfunction at the genetic
Comments to this post would be welcom
j.e.cox at cranfield.ac.uk
John E. Cox