Ueno Hiroshi, Shoshi Chikafumi, Suemitsu Shunsuke, Usui Shinichi, Sujiura Hiroko, Okamoto Motoi
Department of Medical Technology, Graduate School of Health Sciences, Okayama University, Okayama 700-8558, Japan.
Acta Med Okayama. 2013;67(3):135-43. doi: 10.18926/AMO/50406.
In the phenomenon known as cross-modal plasticity, the loss of one sensory system is followed by improved functioning of other intact sensory systems. MRI and functional MRI studies suggested a role of the prefrontal cortex and the temporal lobe in cross-modal plasticity. We used a mouse model to examine the effects of sensory deprivation achieved by whisker trimming and visual deprivation achieved by dark rearing in neonatal mice on the appearance of parvalbumin (PV) neurons and the formation of glutamic acid decarboxylase 67 (GAD67)-positive puncta around pyramidal neurons in the prefrontal cortex and hippocampus. Whisker trimming, but not dark rearing, decreased the density of PV neurons in the hippocampus at postnatal day 28 (P28). In the prefrontal cortex, whisker trimming and dark rearing decreased the density of PV neurons in layer 5/6 (L5/6) at P28 and in L2/3 at P56, respectively, whereas dark rearing increased the density of PV neurons in L5/6 at P56. Whisker trimming decreased the density of GAD67-positive puncta in CA1 of the hippocampus at both P28 and P56 and in L5/6 of the prefrontal cortex at P28. Dark rearing decreased the density of GAD67-positive puncta in CA1 of the hippocampus and in both L2/3 and L5/6 of the prefrontal cortex at P28, and in L2/3 of the prefrontal cortex at P56. These results demonstrate that somatosensory or visual deprivation causes changes in the PV-interneuronal network in the mouse prefrontal cortex and hippocampus. The results also suggest that the alteration of the PV-interneuronal network, especially in the prefrontal cortex, may contribute to cross-modal plasticity.
在被称为跨模态可塑性的现象中，一个感觉系统的丧失会伴随着其他完好感觉系统功能的改善。磁共振成像（MRI）和功能磁共振成像（fMRI）研究表明前额叶皮质和颞叶在跨模态可塑性中发挥作用。我们使用小鼠模型来研究新生小鼠通过剪须实现的感觉剥夺和通过黑暗饲养实现的视觉剥夺对前额叶皮质和海马体中小清蛋白（PV）神经元的出现以及锥体神经元周围谷氨酸脱羧酶67（GAD67）阳性突触点形成的影响。剪须而非黑暗饲养降低了出生后第28天（P28）海马体中PV神经元的密度。在前额叶皮质中，剪须和黑暗饲养分别降低了P28时第5/6层（L5/6）和P56时第2/3层（L2/3）中PV神经元的密度，而黑暗饲养增加了P56时L5/6中PV神经元的密度。剪须降低了P28和P56时海马体CA1区以及P28时前额叶皮质L5/6中GAD67阳性突触点的密度。黑暗饲养降低了P28时海马体CA1区以及前额叶皮质L2/3和L5/6中GAD67阳性突触点的密度，以及P56时前额叶皮质L2/3中GAD67阳性突触点的密度。这些结果表明，体感或视觉剥夺会导致小鼠前额叶皮质和海马体中PV中间神经元网络发生变化。结果还表明，PV中间神经元网络的改变，尤其是前额叶皮质中的改变，可能有助于跨模态可塑性。
