Groc Laurent, Petanjek Zdravko, Gustafsson Bengt, Ben-Ari Yehezkel, Hanse Eric, Khazipov Roustem
Institute of Physiology and Pharmacology, Department of Physiology, Göteborg University, Göteborg, Sweden.
Eur J Neurosci. 2002 Nov;16(10):1931-8. doi: 10.1046/j.1460-9568.2002.02264.x.
During development, neural activity has been proposed to promote neuronal growth. During the first postnatal week, the hippocampus is characterized by an oscillating neural network activity and a rapid neuronal growth. In the present study we tested in vivo, by injecting tetanus toxin into the hippocampus of P1 rats, whether this neural activity indeed promotes growth of pyramidal cells. We have previously shown that tetanus toxin injection leads to a strong reduction in the frequency of spontaneous GABA and glutamatergic synaptic currents, and to a complete blockade of the early neural network activity during the first postnatal week. Morphology of neurobiotin-filled CA1 pyramidal cells was analyzed at the end of the first postnatal week (P6-10). In activity-reduced neurons, the total length of basal dendritic tree was three times less than control. The number, but not the length, of basal dendritic branches was affected. The growth impairment was restricted to the basal dendrites. The apical dendrite, the axons, or the soma grew normally during activity deprivation. Thus, the in vivo neural activity in the neonate hippocampus seems to promote neuronal growth by initiating novel branches.
在发育过程中，有人提出神经活动可促进神经元生长。在出生后的第一周，海马体的特征是神经网络活动振荡和神经元快速生长。在本研究中，我们通过向出生后第1天（P1）大鼠的海马体注射破伤风毒素，在体内测试这种神经活动是否确实促进锥体细胞的生长。我们之前已经表明，注射破伤风毒素会导致自发GABA和谷氨酸能突触电流的频率大幅降低，并在出生后的第一周完全阻断早期神经网络活动。在出生后第一周结束时（P6 - 10）分析了用神经生物素填充的CA1锥体细胞的形态。在活动减少的神经元中，基底树突的总长度比对照少三倍。基底树突分支的数量受到影响，但长度不受影响。生长受损仅限于基底树突。在活动剥夺期间，顶树突、轴突或胞体正常生长。因此，新生海马体中的体内神经活动似乎通过启动新的分支来促进神经元生长。
