Experimental Laboratory, Neurocenter of Southern Switzerland, Lugano, Switzerland.
Exp Neurol. 2013 Sep;247:730-6. doi: 10.1016/j.expneurol.2013.03.018. Epub 2013 Mar 26.
Spreading of slow cortical rhythms into the basal ganglia (BG) is a relatively well-demonstrated phenomenon in the Parkinsonian state, both in humans and animals. Accordingly, striatal dopamine (DA) depletion, either acute or chronic, drives cortical-globus pallidus (GP) and cortical-substantia nigra pars reticulata (SNr) slow wave coherences in urethane-anesthetized rats. This paper investigates the striatal dynamics following acute DA depletion by tetrodotoxin (TTX) injection in the medial forebrain bundle (MFB) with respect to the transmission of slow cortical rhythms throughout the BG in more detail. The acute DA depletion offers the advantage of detecting electrophysiological changes irrespectively of chronically developing compensatory mechanisms. We observed that the acute blockade of the dopaminergic nigro-striatal pathway reshapes the firing rate and pattern of the different striatal neuron subtypes according to cortical activity, possibly reflecting a remodeled intrastriatal network. The observed alterations differ amongst striatal neuronal subtypes with the striatal medium spiny neurons and fast-spiking neurons being the most affected, while the tonically active neurons seem to be less affected. These acute changes might contribute to the diffusion of cortical activity to BG and the pathophysiology of Parkinson's disease (PD).
皮质慢节律向基底神经节（BG）的扩散是帕金森病状态中一个相对得到充分证明的现象，无论是在人类还是动物中。因此，纹状体多巴胺（DA）的耗竭，无论是急性还是慢性的，都会导致在乌拉坦麻醉的大鼠中引起皮质-苍白球（GP）和皮质-黑质网状部（SNr）的慢波相干性。本文通过在中脑束（MFB）中注射河豚毒素（TTX）来研究急性 DA 耗竭后的纹状体动力学，以更详细地研究慢皮质节律在整个 BG 中的传递。急性 DA 耗竭的优点是可以检测到电生理变化，而无需考虑慢性发展的代偿机制。我们观察到，多巴胺能黑质纹状体通路的急性阻断根据皮质活动重塑了不同纹状体神经元亚型的放电率和模式，可能反映了重塑的纹状体内网络。观察到的改变因纹状体神经元亚型而异，纹状体中型棘突神经元和快速棘突神经元受影响最大，而持续活动神经元似乎受影响较小。这些急性变化可能有助于皮质活动向 BG 的扩散和帕金森病（PD）的病理生理学。
