NEUROTRANSMITTER UPTAKE INTO SLICES OF RAT CEREBRAL CORTEX IN VITRO: EFFECT OF SLICE SIZE

Abstract— The uptake of ¹⁴C]GABA, ¹⁴C]taurine, ³H] β -alanine and ¹⁴C]dopamine was compared in slices of rat cerebral cortex of three different sizes (0.1 × 0.1 × 2 mm, 0.2 × 0.2 × 2 mm and 0.4 × 0.4 × 2 mm prepared with a mechanical tissue chopper). ¹⁴C]Taurine and ³H] β -alanine uptake increased whereas ¹⁴C]GABA uptake decreased with increasing slice size. ¹⁴C]Dopamine uptake was optimal in 0.2 × 0.2 × 2 mm slices. Increasing slice size was shown to decrease inhibition of ³H] β -alanine and ¹⁴C]GABA uptake by l -2,4-diaminobutyric acid. Lactate dehydrogenase activity increased with increasing slice size indicating decreased tissue damage or increased cellular integrity. The possibility that varying slice size can be used to distinguish between neuronal and glial uptake is discussed. It is suggested that taurine uptake in the cerebral cortex is predominantly glial.