Protection against glutamate toxicity through inhibition of the p44/42 mitogen-activated protein kinase pathway in neuronally differentiated P19 cells22Abbreviations: AMPA, (±)-α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid; NMDA, N-methyl-d-aspartate; MAP, mitogen-activated protein; ERK1/2, extracellular signal regulated kinase 1/2; MEK, mitogen-activated protein kinase kinase; JNK, Jun N-terminal kinase; NO, nitric oxide; CDK1, cyclin-dependent kinase I; PKA, protein kinase A; PKC, protein kinase C; CK1/2, casein kinase 1/2; EGFR, epidermal growth factor receptor; CaM-K, calcium/calmodulin-dependent kinase; ATRA, all-trans-retinoic acid; RT-PCR, reverse transcriptase-polymerase chain reaction; and CFDA, carboxyfluorescein diacetate.