Marwaha J, Hoffer B, Pittman R, Freedman R
Brain Res. 1980 Nov 10;201(1):85-97. doi: 10.1016/0006-8993(80)90777-5.
The spontaneous discharge of cerebellar Purkinje neurons was studied in 3-, 12-, 15-, and 20-month-old rats. Fluphenazine and haloperidol administered intraperitoneally produced a dose-dependent increase in the spontaneous discharge in 3-month-old animals, but were ineffective in 12-, 15- and 20-month-old rats. Intraperitoneal administration of amphetamine resulted in a dose-dependent decrease in spontaneous Purkinje neuron discharge in 3-month-old rats without affecting neurons from the older animals. Discrution of norepinephrine afferents by 6-OHDA or reserpine increased spontaneous discharge rate in 3-month-old animals. This treatment did not affect Purkinje neurons in 12-, 15- and 20-month-old rats. Local application of drug with the same multibarreled electrode revealed that neurons from older rats were significantly less sensitive to inhibition by norepinephrine than were Purkinje neurons from 3-month-old animals. Similar application of GABA did not reveal a differential sensitivity. For locus coeruleus activation to produce 50% inhibition in Purkinje neuron discharge, significantly higher stimulation currents were required in 15-month-old rats than in 3-month-old animals. Our results suggest a decreased postsynaptic sensitivity to norepinephrine in 12-, 15- and 20-month-old rats as compared to 3-month-old animals.
在3个月、12个月、15个月和20个月大的大鼠中研究了小脑浦肯野神经元的自发放电。腹腔注射氟奋乃静和氟哌啶醇会使3个月大大鼠的自发放电呈剂量依赖性增加，但对12个月、15个月和20个月大的大鼠无效。腹腔注射苯丙胺会使3个月大大鼠浦肯野神经元的自发放电呈剂量依赖性减少，而对年龄较大动物的神经元没有影响。用6-OHDA或利血平破坏去甲肾上腺素传入神经会增加3个月大大鼠的自发放电率。这种处理对12个月、15个月和20个月大的大鼠的浦肯野神经元没有影响。用同一多管电极局部给药显示，与3个月大大鼠的浦肯野神经元相比，年龄较大大鼠的神经元对去甲肾上腺素抑制的敏感性明显较低。类似地应用GABA并未显示出差异敏感性。为了使蓝斑激活在浦肯野神经元放电中产生50%的抑制，15个月大大鼠所需的刺激电流明显高于3个月大大鼠。我们的结果表明，与3个月大大鼠相比，12个月、15个月和20个月大的大鼠对去甲肾上腺素的突触后敏感性降低。
