Takeda M, Onoda N, Suzuki M
Department of Physiology, Medical School, Gunma University, Maebashi, Japan.
Thyroid. 1994 Winter;4(4):467-74. doi: 10.1089/thy.1994.4.467.
To characterize the effect of thyroid hormone on the central nervous system in adult rats, we recorded evoked potentials by photic (VEP) and electrical stimulation in normal, thyroidectomized (Tx) and T3- or T4-supplemented (Tx-T3, Tx-T4) male adult rats under pentobarbital anesthesia. The latencies of VEPs recorded in the visual cortex (VC) and lateral geniculate nucleus (LGN), and the b-waves of the electroretinograms (ERG) of these three groups were compared. A significant prolongation of the latency of VEP by photic stimulation (flash light intensity 2J, 0.2 Hz) in the VC was observed 14 to 28 days after thyroidectomy (27.9 +/- 0.4 vs. 33.4 +/- 0.43 msec, p < 0.01). Similar prolongations were also observed when those of the VEP in the LGN and the b-wave of the ERG were compared to those of normal rats (22.4 +/- 0.37 vs. 27.3 +/- 0.41 msec, p < 0.01; 21.8 +/- 0.21 vs. 25.3 +/- 0.41 msec, p < 0.01, respectively). The prolonged latencies observed in the VC, LGN, and ERG-b-wave were partially normalized 24 hr after T3 supplement (50 micrograms/kg, sc) and fairly restored to normal levels by 48 hr after T4 injection (100 micrograms/kg sc). The VEP latencies in the LGN and VC showed a positive correlation with the b-wave latency of the ERG in these three groups.(ABSTRACT TRUNCATED AT 250 WORDS)
为了研究甲状腺激素对成年大鼠中枢神经系统的影响，我们在戊巴比妥麻醉下，对正常、甲状腺切除（Tx）以及补充T3或T4（Tx-T3、Tx-T4）的成年雄性大鼠进行光刺激（VEP）和电刺激以记录诱发电位。比较了这三组在视皮层（VC）和外侧膝状体核（LGN）记录的VEP潜伏期以及视网膜电图（ERG）的b波。甲状腺切除术后14至28天，观察到VC中光刺激（闪光强度2J，0.2Hz）诱发的VEP潜伏期显著延长（27.9±0.4对33.4±0.43毫秒，p<0.01）。将LGN中的VEP潜伏期和ERG的b波与正常大鼠相比时，也观察到类似的延长（分别为22.4±0.37对27.3±0.41毫秒，p<0.01；21.8±0.21对25.3±0.41毫秒，p<0.01）。补充T3（50微克/千克，皮下注射）24小时后，VC、LGN和ERG - b波中观察到的延长潜伏期部分恢复正常，注射T4（100微克/千克，皮下注射）48小时后基本恢复到正常水平。在这三组中，LGN和VC中的VEP潜伏期与ERG的b波潜伏期呈正相关。（摘要截断于250字）
