Decreased calcium/calmodulin-dependent protein kinase II and protein kinase C activities mediate impairment of hippocampal long-term potentiation in the olfactory bulbectomized mice.
Olfactory bulbectomized (OBX) mice showed significant impairment of learning and memory-related behaviors 14 days after olfactory bulbectomy, as measured by passive avoidance and Y-maze tasks. We here observed a large impairment of hippocampal long-term potentiation (LTP) in the OBX mice. Concomitant with decreased acetylcholinesterase expression, protein kinase C (PKC)alpha autophosphorylation and NR1(Ser-896) phosphorylation significantly decreased in the hippocampal CA1 region of OBX mice. Both PKCalpha and NR1(Ser-896) phosphorylation significantly increased following LTP in the control mice, whereas increases were not observed in OBX mice. Like PKC activities, calcium/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation significantly decreased in the hippocampal CA1 region of OBX mice as compared with that of control mice. In addition, increased CaMKII autophosphorylation following LTP was not observed in OBX mice. Finally, the impairment of CaMKII autophosphorylation was closely associated with reduced pGluR1(Ser-831) phosphorylation, without change in synapsin I (site 3) phosphorylation in the hippocampal CA1 region of OBX mice. Taken together, in OBX mice NMDA receptor hypofunction, possibly through decreased PKCalpha activity, underlies decreased CaMKII activity in the post-synaptic regions, thereby impairing LTP induction in the hippocampal CA1 region. Both decreased PKC and CaMKII activities with concomitant LTP impairment account for the learning disability observed in OBX mice.
Moriguchi
Shigeki
S
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan. shigeki@mail.pharm.tohoku.ac.jp
Han
Feng
F
Nakagawasai
Osamu
O
Tadano
Takeshi
T
Fukunaga
Kohji
K
D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000378:metabolism; D000544:Alzheimer Disease / Q000378:metabolism / Q000503:physiopathology; D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002799:Cholinergic Fibers / Q000378:metabolism / Q000473:pathology; D003714:Denervation / Q000009:adverse effects*; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000502:physiology; D004525:Efferent Pathways / Q000293:injuries / Q000378:metabolism / Q000503:physiopathology; D006624:Hippocampus / Q000378:metabolism* / Q000503:physiopathology; D007859:Learning Disabilities / Q000378:metabolism / Q000503:physiopathology; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D008569:Memory Disorders / Q000378:metabolism / Q000503:physiopathology; D051379:Mice; D009830:Olfactory Bulb / Q000293:injuries* / Q000378:metabolism / Q000503:physiopathology; D009924:Organ Culture Techniques; D010766:Phosphorylation; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D018091:Receptors, AMPA / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
C409466:NR1 NMDA receptor; D018091:Receptors, AMPA; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; C104077:metabotropic glutamate receptor type 1; D051571:Protein Kinase C-alpha; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D000110:Acetylcholinesterase; D000109:Acetylcholine