HIGH-SENSITIVITY QUANTITATIVE-ANALYSIS OF COBALT UPTAKE IN RAT CEREBELLAR GRANULE CELLS WITH AND WITHOUT EXCITATORY AMINO-ACIDS

We quantified the effect of the excitatory amino acids kainate and glu tamate on the uptake of cobalt in primary rat cerebellar granule neuro ns, by using inductively coupled plasma-atomic emission spectroscopy ( ICP-AES). We quantitatively demonstrated that Co2+ uptake, although en hanced by glutamate and kainate also takes place in the absence of exc itatory amino acids. We also found that cobalt uptake is not significa ntly altered by the presence of glutamate receptor competitive or nonc ompetitive antagonists, indicating that cobalt uptake in granule neuro ns does not require glutamate receptor stimulation. Our results sugges t, therefore, that Co2+ may enter the cell by passive diffusion throug h the plasma membrane. (C) 1998 Elsevier Science Ireland Ltd.