Mcginnis M Y, Gordon J H, Gorski R A
Brain Res. 1980 Feb 17;184(1):179-97. doi: 10.1016/0006-8993(80)90596-x.
In the first experiment the role of gamma-aminobutyric acid (GABA) in the display of lordosis behavior was examined in septal-lesioned and sham-operated ovariectomized rats. Following estradiol benzoate (EB) priming, septal-lesioned rats were tested for lordosis behavior before and after bilateral infusion of picrotoxin or saline directly into the substantia nigra (SN). Sham animals were given the same behavioral tests but received intranigral infusion of either hydrazinopropionic acid (HPA) or saline. Picrotoxin, which blocks GABA receptors, was effective in suppressing the high levels of lordosis behavior seen in the EB-primed septal-lesioned female rat 30 min after infusion, but not at 120 min. Conversely, HPA, which elevates endogenous GABA levels, was effective in facilitating lordosis behavior in sham-operated rats treated with EB only. The lordosis quotient was moderately increased 30 min after HPA infusion, reached high levels at 120 min, and returned to low levels by 360 min post-infusion, demonstating the reversibility of the drug effect. Saline infusions in lesioned and sham-operated controls were without effect. In the second experiment sepal-lesioned and sham-operated rats were primed with EB and infused with the drugs as in the first experiment, but were sacrificed at the time the macimal behavioral effect had been observed in the first experiment. Tyrosine hydroxylase (TH) activity and dopamine (DA) and homovanillic acid (HVA) levels were measured. No effect on TH activity was found. However, sham-operated rats receiving HPA infusions had lower DA and HVA levels compared to those of saline-injected controls, and septal-lesioned rats receiving picrotoxin infusions had higher DA and HVA levels than those of lesioned saline-injected controls. Septal-lesioned saline-infused rats also showed decreased DA and HVA levels relative to sham-operated saline-infused animals. These results support the concept of a GABA inhibitory neuronal feedback system which modulates DA turnover and perhaps plays a critical role in the neural control of lordosis behavior.
在第一个实验中，研究了γ-氨基丁酸（GABA）在隔区损伤和假手术的去卵巢大鼠中对脊柱前凸行为表现的作用。经苯甲酸雌二醇（EB）预处理后，在向黑质（SN）双侧注射印防己毒素或生理盐水之前和之后，对隔区损伤大鼠进行脊柱前凸行为测试。假手术动物接受相同的行为测试，但接受黑质内注射肼基丙酸（HPA）或生理盐水。阻断GABA受体的印防己毒素在注射后30分钟可有效抑制经EB预处理的隔区损伤雌性大鼠中出现的高水平脊柱前凸行为，但在120分钟时无效。相反，提高内源性GABA水平的HPA仅对经EB处理的假手术大鼠的脊柱前凸行为有促进作用。HPA注射后30分钟，脊柱前凸商适度增加，120分钟时达到高水平，注射后360分钟恢复到低水平，表明药物作用具有可逆性。损伤组和假手术对照组注射生理盐水均无效果。在第二个实验中，隔区损伤和假手术大鼠经EB预处理并如第一个实验那样注射药物，但在第一个实验中观察到最大行为效应时将其处死。测量酪氨酸羟化酶（TH）活性以及多巴胺（DA）和高香草酸（HVA）水平。未发现对TH活性有影响。然而，接受HPA注射的假手术大鼠的DA和HVA水平低于注射生理盐水的对照组，接受印防己毒素注射的隔区损伤大鼠的DA和HVA水平高于损伤组注射生理盐水的对照组。相对于假手术注射生理盐水的动物，隔区损伤注射生理盐水的大鼠也表现出DA和HVA水平降低。这些结果支持了GABA抑制性神经元反馈系统的概念，该系统调节DA的周转，可能在脊柱前凸行为的神经控制中起关键作用。
