Figure 7.

Selective loading and release of d-[³H]serine from neuronal cells. A) d-[³H]serine uptake in neuronal (•) or astrocytic (○) primary cultures was assayed in a Na⁺-free in which cholineCl was substituted for NaCl (Na⁺-free HCSS). B) Release of d-[³H]serine from cortical slices preloaded with d-[³H]serine in the absence of Na⁺. Cortical slices were first loaded with d-[³H]serine in HMK containing cholineCl instead of NaCl. Then, the slices were perfused with NaCl-containing HMK, and d-[³H]serine release was elicited by veratridine. Results represent average ± se of 4 or 5 experiments with different preparations done in triplicates. Neu, neurons; Ast, astrocytes.