I guess the major issue has involved the interpretation of your original
question. Depletion of ALL calcium will cause death. A maintained level of
calcium is required for normal functioning. So I think the rather negative
responses to your question has been that you can't divorce functioning with
an absence of calcium. It would be similar to me setting up a post asking
about what would happen if all the oxygen on earth would suddenly be
removed. What would happen to consciousness, awareness, emotions, etc.???
However, within your question there is an aspect of creative insight and
purposefulness. The question is valid if certain conditions are maintained
The major thing that you may want to consider is not permanent removal of
calcium but a transient suppression in such a manner not to cause the total
deleterious effects upon physiological functioning like death that would
occur during total calcium removal. You mention what you happen if a bout
of hypocalcemia was restricted to areas of the brain localized to these
1. voluntary movement (including speech; excluding breathing)
2. memories (all types)
10. senses of vision, hearing, and balance
If you can show me conclusively where "awareness", "consciousness",
"attention", "association", or "emotion" is localized within the brain I
will be looking forward to hear your nomination this October-November from
the Royal Swedish Academy of Sciences.
If we consider that the extracellular levels of calcium are maintained, but
there is some particular functioning within some channels conducting
calcium. For the example of memory, we know that calcium is an extremely
important ion that triggers biochemical signaling in such a manner that can
induce changes in synaptic functioning. A variety of studies have
implemented the role of L-type voltage dependent calcium channels in
facilitating the necessary changes in synaptic efficacy that accompany
stimulation. In this case depletion of the transient conductance of calcium
through these channels will interference in the extent of calcium-dependent
biochemical signaling. As a result the extent of synaptic changes that are
the result of learning is functionally suppressed.
For wide-range diverse functions: Some of Becker's work has shown that
within glial cells slow activity is produced that can mediate the occurrence
of infraslow potentials that proliferates within neuronal tissue. This slow
wave process has been considered to be calcium mediated. The infraslow
potentials have been implemented in many cognitive functioning. Therefore,
interference in calcium waves will functionally suppress these infraslow
potentials / rhythms as they propagate throughout the entire syncitium.
Thus transiently affecting calcium could interfere with these processes.
However, consider when you say "completely loose there supply of calcium"
that this will evoke the same effect as too much calcium. At the extreme
ends depletion of calcium will evoke death and too much calcium will evoke
death. However, there is also a creative aspect of your question that I
don't think the other individuals who have respond consider.
Say you transiently remove all the extracellular calcium and you were
capable of measuring ALL the type of changes that accompany such a process
on an extremely small time scale. What I'm saying is there will be no
limitation or lag in measurement. I would theorize that a sudden removal of
all extracellular calcium within a small area (say a few 100 neurons) will
cause the internal membrane stores of calcium within neuronal organelles to
expel out and be released. This would allow for interaction with
calcium-dependent signaling and transient interaction with ion channels
themselves. Furthermore, some have speculate that because of the
interesting electrovalent processes that the calcium ion can possess, unique
electrostatic interactions can help influence the "voltage sensors" of
resting sodium and potassium channels. However, if this loss is permanent
then the neuron will die. Before this period of necrosis, however, there
would interesting cellular activity. For example the sudden release of
internal calcium store might trigger a calcium spike. Therefore, there is
the possibility that during this period unique alterations will occur in
cognitive functioning. Profound hallucinations and alterations in behavior
are often noticed in individuals suffering hypocalcemia.
Lastly, I would suggest reading a little more about the concept of neuronal
relaxation. This is often a difficult concept to grasp and many people
often make mistake with many of the operations and processes that are occur
during "relaxation". There ARE no NORMAL (IN VIVO) conditions when a
neuron is relaxed in the humanistic sense. That is an absence of activity.
If the neuron is not active it dies. Period. Activation is required. Even
if the end result may not be to trigger response in its receptive
connections, neuronal activation always takes place. If you ever have the
opportunity to make any kind of cellular recordings you will instantly
realize that neurons are always active and never quiescent.
Any how your question does have a level or merit.