Developmental changes in high-affinity uptake of GABA by cultured neurons.
High-affinity uptake of [3H]gamma-aminobutyric acid (GABA) was studied in cultures of neonatal rat cortical neurons grown on pre-formed monolayers of non-neuronal (glial) cells. Both the maximum rate (Vmax) and, to a smaller extent, the Km of [3H]GABA uptake increased with time. In addition, in parallel with these changes, 2,4-diaminobutyric acid and cis-3-aminocyclohexane-1-carboxylic acid (ACHC), compounds which are considered typical substrate/inhibitors of GABA uptake in neurons, became progressively stronger inhibitors of [3H]GABA uptake. Consequently, the present results may mean that the studies using uptake of [3H]GABA, [3H]ACHC, or [3H]DABA as a specific marker for GABAergic neurons differentiating during the ontogenetic development of the central nervous system may have to be interpreted with caution.
Balcar
V J
VJ
Biological Research Laboratories, CIBA-GEIGY Ltd., Basel, Switzerland.
Hauser
K L
KL
Demieville
H
H
D000083:Acetanilides / Q000494:pharmacology; D000596:Amino Acids / Q000494:pharmacology; D000598:Amino Acids, Cyclic; D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology; D051381:Rats; D005680:gamma-Aminobutyric Acid / Q000493:pharmacokinetics*
D000083:Acetanilides; D000596:Amino Acids; D000598:Amino Acids, Cyclic; D003509:Cyclohexanecarboxylic Acids; C015666:3-aminocyclohexanecarboxylic acid; C002605:DABA; D005680:gamma-Aminobutyric Acid