Biomedical Engineering Reference
In-Depth Information
Of interest is the observation that the various tasks of
astrocytes may preferentially activate oxidative or glycolytic
metabolism. In a recent study using 2-photon NADH imaging,
we found that cortical spreading depression was associated with a
sharp decrease in NADH signaling reflecting increased oxidation
in perivascular endfeet. The decrease in NADH occurred during
the repolarization phase during which plasma membrane pumps
are engaged in normalization of ion gradients
(75)
.
7. Concluding
Remarks
Deciphering the metabolic responses of astrocytes in response to
neural activation is likely to add a new dimension to our under-
standing of BOLD signal changes during fMRI. A question for
future research is whether astrocytic Ca
2
+
signaling is necessary
and sufficient for increases in local blood flow similar to what have
been demonstrated in mice using targeted photolysis of caged
Ca
2
+
(51)
.
Acknowledgments
This
work
was
supported
by
NINDS/NIH
NS030007,
NS038073, NS50315.
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