TY - JOUR
T1 - Astrocytic involvement in learning and memory consolidation
AU - Gibbs, Marie Elizabeth
AU - Hutchinson, Dana Sabine
AU - Hertz, Leif
PY - 2008
Y1 - 2008
N2 - Astrocytes play fundamental roles in brain function, interacting with neurons and other astrocytes, yet their role in learning is not widely recognized. This review focuses on astrocytic involvement in memory consolidation following bead discrimination learning in day-old chick and draws parallels to mammalian learning, providing strong empirical support for the conclusion that the described neuronal-astrocytic interactions are universally valid. It identifies specific mechanisms whereby astrocytes support memory consolidation. Uptake of glucose, stimulated in astrocytes by beta(3)-noradrenergic receptor activation, provides energy by glycolytic/oxidative metabolism. Unlike neurons, astrocytes carry out net synthesis of tricarboxylic acid cycle intermediates needed for synthesis of transmitter glutamate formed by rapid degradation of glucose-derived glycogen and stimulated by beta(2)-noradrenergic receptor activation. This makes learning dependent on glycogenolysis and its stimulation by noradrenaline. Astrocytes take up most synaptically released glutamate, terminating transmitter activity and returning glutamate to neurons in a glutamate-glutamine cycle, interference with which abolishes learning. The various astrocytic activities follow a rigidly controlled time schedule, easily determined after bead discrimination learning but also detectable in other paradigms.
AB - Astrocytes play fundamental roles in brain function, interacting with neurons and other astrocytes, yet their role in learning is not widely recognized. This review focuses on astrocytic involvement in memory consolidation following bead discrimination learning in day-old chick and draws parallels to mammalian learning, providing strong empirical support for the conclusion that the described neuronal-astrocytic interactions are universally valid. It identifies specific mechanisms whereby astrocytes support memory consolidation. Uptake of glucose, stimulated in astrocytes by beta(3)-noradrenergic receptor activation, provides energy by glycolytic/oxidative metabolism. Unlike neurons, astrocytes carry out net synthesis of tricarboxylic acid cycle intermediates needed for synthesis of transmitter glutamate formed by rapid degradation of glucose-derived glycogen and stimulated by beta(2)-noradrenergic receptor activation. This makes learning dependent on glycogenolysis and its stimulation by noradrenaline. Astrocytes take up most synaptically released glutamate, terminating transmitter activity and returning glutamate to neurons in a glutamate-glutamine cycle, interference with which abolishes learning. The various astrocytic activities follow a rigidly controlled time schedule, easily determined after bead discrimination learning but also detectable in other paradigms.
UR - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18462796
M3 - Article
SN - 0149-7634
VL - 32
SP - 927
EP - 944
JO - Neuroscience and Biobehavioral Reviews
JF - Neuroscience and Biobehavioral Reviews
IS - 5
ER -