EFFECT OF EXCITATORY AMINO-ACIDS ON MICROTUBULE-ASSOCIATED PROTEINS IN CULTURED CORTICAL AND SPINAL NEURONS

The effect of excitatory amino acid stimulation on the cytoskeleton of cultured spinal cord and cortical neurons was monitored with antibodies against microtubule-associated proteins tau and MAP2. In unstimulated cultures tau-1 immunoreactivity was restricted to axon-like processes. Stimulation with glutamate (0.1-1 mM) or N-methyl-d-aspartate (NMDA) (0.1 mM) resulted in a dramatic increase in the intensity of tau labelling in axons and the appearance of staining within a proportion of neuronal cell bodies and dendrites. Quisqualate or kainate stimulation resulted only in an increase in tau immunoreactivity within axons. The NMDA mediated events were calcium dependent and the effects of all excitatory amino acids could be blocked by specific antagonists. In contrast, following stimulation with excitatory amino acids, MAP2-immunoreactivity was associated with filaments which formed a complex network within the cell body. This suggests that the different excitatory amino acid receptor subtypes can have differential effects on the neuronal cytoskeleton. © 1990.