Inhibition of mGluR1 and IP3Rs impairs long-term memory formation in young chicks.
Calcium (Ca(2+)) is involved in a myriad of cellular functions in the brain including synaptic plasticity. However, the role of intracellular Ca(2+) stores in memory processing remains poorly defined. The current study explored a role for glutamate-dependent intracellular Ca(2+) release in memory processing via blockade of metabotropic glutamate receptor subtype 1 (mGluR1) and inositol (1,4,5)-trisphosphate receptors (IP(3)Rs). Using a single-trial discrimination avoidance task developed for the young chick, administration of the specific and potent mGluR1 antagonist JNJ16259685 (500nM, immediately post-training, ic), or the IP(3)R antagonist Xestospongin C (5microM, immediately post-training, ic), impaired retention from 90min post-training. These findings are consistent with mGluR1 activating IP(3)Rs to release intracellular Ca(2+) required for long-term memory formation and have been interpreted within an LTP2 model. The consequences of different patterns of retention loss following ryanodine receptor (RyR) and IP(3)R inhibition are discussed.
Baker
K D
KD
School of Psychology, Psychiatry and Psychological Medicine, Monash University, Clayton, 3800 Vic., Australia. Kathryn.Baker@med.monash.edu.au
Edwards
T M
TM
Rickard
N S
NS
D000367:Age Factors; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D047028:Macrocyclic Compounds / Q000494:pharmacology; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D010080:Oxazoles / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000378:metabolism*
C495417:(3,4-dihydro-2H-pyrano(2,3)b-quinolin-7-yl)-(cis-4-methoxycyclohexyl) methanone; D053496:Inositol 1,4,5-Trisphosphate Receptors; D047028:Macrocyclic Compounds; D010080:Oxazoles; D011804:Quinolines; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1; C511704:xestospongin C; D002118:Calcium