Brain glucose sensing: a subtle mechanism

Luc Pénicaud, Corinne Leloup, Xavier Fioramonti, Anne Lorsignol, Alexandre Benani
Current Opinion in Clinical Nutrition & Metabolic Care. 2006-07-01; 9(4): 458-462
DOI: 10.1097/01.mco.0000232908.84483.e0

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1. Curr Opin Clin Nutr Metab Care. 2006 Jul;9(4):458-62. doi:
10.1097/01.mco.0000232908.84483.e0.

Brain glucose sensing: a subtle mechanism.

Pénicaud L(1), Leloup C, Fioramonti X, Lorsignol A, Benani A.

Author information:
(1)Université Toulouse III, Toulouse, France.

PURPOSE OF REVIEW: Brain nutrient sensing allows a fine regulation of different
physiological functions, such as food intake and blood glucose, related to
energy homeostasis. Glucose sensing is the most studied function and a parallel
has been made between the cellular mechanisms involved in pancreatic beta cells
and neurons.
RECENT FINDINGS: Two types of glucosensing neurons have been
characterized–those for which the activity is proportional to changes in
glucose concentration and those for which the activity is inversely proportional
to these changes. A new level of complexity has recently been demonstrated, as
the response and the mechanism appear to vary in function according to the level
of the glucose change. For some of the responses, the detection is probably not
at the level of the neuron itself, but astrocytes also appear to be involved,
indicating a coupling between the two types of cells. Finally, numerous data
have demonstrated the modulation of glucose sensing by other nutrients, in
particular fatty acids, hormones (insulin, leptin and ghrelin) and peptides
(neuropeptide Y). This implies a common pathway in which AMPkinase may play a
crucial role.
SUMMARY: Recent observations in brain nutrient sensing indicate subtle
mechanisms, with different cellular and molecular mechanisms involved. This fact
would explain the discrepancies reported in the expression of different proteins
(glucose transporters, hexokinases, channels). Astrocytes may be involved in one
type of response, thus adding a new level of complexity.