Hedner T, Iversen K, Lundborg P
J Neural Transm. 1984;59(2):105-18. doi: 10.1007/BF01255409.
Various biochemical characteristics of the developing GABA system was studied in rats from 1 to 60 days of age. Endogenous GABA concentrations were high in the limbic system, midbrain, brain stem and spinal cord at birth. Until 7 days of postnatal age, GABA concentrations generally decreased, thereafter an increase was seen and at 60 days of age the GABA concentrations exceeded those found in the neonate except for the spinal cord regions. After GABA-T inhibition with AOAA, GABA concentrations increased in all brain regions, however considerably more marked in the 28 days old rats compared to the 4 days old animals. Turnover rate of GABA was estimated by investigating the rate of disappearance of GABA after GAD inhibition with 3-MPA. Calculated turnover time of whole brain GABA was 34.1 min in the 4 days old rats and 19.9 min in the 28 days old animals. The results from this investigation clearly indicate a caudal to rostral maturational gradient in the development of endogenous GABA concentrations as well as synthesis capacity. Furthermore, turnover rate of total whole brain GABA but probably not of GABA in the neuronal pool is retarded in the 4 days old rats compared to the adolescent animals.
研究了1至60日龄大鼠发育中的γ-氨基丁酸（GABA）系统的各种生化特性。出生时，边缘系统、中脑、脑干和脊髓中的内源性GABA浓度较高。在出生后7天之前，GABA浓度普遍下降，此后出现上升，到60日龄时，除脊髓区域外，GABA浓度超过了新生儿期的水平。在用氨氧乙酸（AOAA）抑制GABA转氨酶（GABA-T）后，所有脑区的GABA浓度均升高，但与4日龄动物相比，28日龄大鼠的升高更为明显。通过研究用3-巯基丙酸（3-MPA）抑制谷氨酸脱羧酶（GAD）后GABA的消失速率来估计GABA的周转率。4日龄大鼠全脑GABA的计算周转时间为34.1分钟，28日龄动物为19.9分钟。这项研究的结果清楚地表明，内源性GABA浓度以及合成能力的发育存在从尾端到吻端的成熟梯度。此外，与青春期动物相比，4日龄大鼠全脑GABA的周转率，但可能不是神经元池中的GABA周转率，有所延迟。
