Chirality  Clausenamide  Dementia  Long-term potentiation  Signaling pathway  Calcium  6-OHDA  6-hydroxyldopamine  ACE  acetylcholinesterase  ACh  acetylcholine  AD  Alzheimer's disease  AUC0–12 h  0–12 h area under curve  APP  amyloid precursor protein  APV  R-2-amino-5-phosphonopentanoate  AUC0−∝  whole area under curve  BBB  blood–brain barrier  BDNF  brain-derived neurotrophic factor  CaM  calmodulin  CaMKII  calmodulin kinase II  ChAT  choline acetyltransferase  CREB  cAMP responding element binding  CHM  Chinese herbal medicine  clau  clausenamide  CL  clearance  Cmax  maximum concentration  CDK-5  cyclin-dependent kinase-5  DM  diabetes mellitus  DAG  diacylglycerol  ER  endoplasmic reticulum  ERK  extracellular signal-regulated kinases  GSK-3  glycogen synthase kinase-3  IP3  inositol triphosphate  LTP  long term potentiation  MWM  Morris water maze  NGF  nerve growth factor  NMDA  N-Methyl-D-aspartate  D  nNOS  neural nitric oxide synthase  PAT  passive avoidance tasks  Pir  piracetam  PLC  phospholipase C  PP1  phosphate 1  PKC  protein kinase C  tmax  time of peak concentration  t1/2α  absorption half-life  t1/2β  elimination half-life  Tau  microtubule-associated proteins  TCM  traditional Chinese medicine  Vd  apparent volume of distribution  VDCC  voltage-dependent calcium channel