Chen Fenghua, Madsen Torsten M, Wegener Gregers, Nyengaard Jens R
Stereology and Electron Microscopy Research Laboratory and MIND Center, Aarhus University, DK-8000 Aarhus C, Denmark.
Hippocampus. 2008;18(7):631-9. doi: 10.1002/hipo.20423.
Neuronal plasticity in hippocampus is hypothesized to play an important role in both the pathophysiology of depressive disorders and the treatment. In this study, we investigated the consequences of imipramine treatment on neuroplasticity (including neurogenesis, synaptogenesis, and remodelling of synapses) in subregions of the hippocampus by quantifying number of neurons and synapses. Adult male Sprague-Dawley rats were injected with imipramine or saline (i.p.) daily for 14 days. Unbiased stereological methods were used to quantify the number of neurons and synapses. No differences in the volume and number of neurons of hippocampal subregions following imipramine treatment were found. However, the number and percentage of CA1 asymmetric spine synapses increased significantly and, conversely, the percentage of asymmetric shaft synapses significantly decreased in the imipramine treated group. Our results indicate that administration of imipramine for 14 days in normal rats could significantly increase the excitatory spine synapses, and change the relative distribution of spine and shaft synapses. We speculate that the present findings may be explained by the establishment of new synaptic connections and by remodelling or transformation of existing synapses.
海马体中的神经元可塑性被认为在抑郁症的病理生理学和治疗中都起着重要作用。在本研究中，我们通过量化神经元和突触的数量，研究了丙咪嗪治疗对海马体各亚区神经可塑性（包括神经发生、突触形成和突触重塑）的影响。成年雄性Sprague-Dawley大鼠每天腹腔注射丙咪嗪或生理盐水，持续14天。采用无偏立体学方法量化神经元和突触的数量。丙咪嗪治疗后，未发现海马体亚区神经元的体积和数量有差异。然而，在丙咪嗪治疗组中，CA1不对称棘突触的数量和百分比显著增加，相反，不对称轴突突触的百分比显著降低。我们的结果表明，在正常大鼠中给予丙咪嗪14天可显著增加兴奋性棘突触，并改变棘突触和轴突突触的相对分布。我们推测，目前的发现可能是由于新突触连接的建立以及现有突触的重塑或转变所致。
