Cholinergic modulation of response properties and orientation tuning of neurons in primary visual cortex of anaesthetized Marmoset monkeys.
Cholinergic modulation of response properties and orientation tuning of neurons in primary visual cortex of anaesthetized Marmoset monkeys.
复制标题
DOI：
10.1111/j.1460-9568.2006.04882.x
复制
发表时间：
2006-07
影响因子：
3.4
通讯作者：
Thiele, A
中科院分区：
文献类型：
--
作者：
Zinke, W;Roberts, M J;Guo, K;McDonald, J S;Robertson, R;Thiele, A
皮质处理受到神经调质如乙酰胆碱（ACh）的作用的强烈影响。在麻醉猫的早期研究认为，乙酰胆碱可以导致锐化的方向调谐功能和改善的信号噪声比（SNR）的神经元反应在初级视觉皮层（V1）。最近的体外研究表明，乙酰胆碱通过激活毒蕈碱受体降低反馈和皮质内连接的功效，并通过激活烟碱受体增加前馈连接的功效。如果定向调谐是由皮质内连接介导或增强的，那么高水平的乙酰胆碱应该会减弱定向调谐。在这里，我们调查的影响，乙酰胆碱的方向调谐和神经元的反应性麻醉绒猴。我们发现，乙酰胆碱引起了扩大的方向调谐在大多数细胞，而调谐功能变得尖锐，只有少数细胞。此外，乙酰胆碱一般促进神经元的反应，但既没有改善信噪比，也没有减少试验到试验的放电率方差系统。然而，乙酰胆碱，减少尖峰列车内的尖峰发生的变异性。我们讨论这些发现的背景下，动态控制的前馈和横向/反馈连接乙酰胆碱。
Cortical processing is strongly influenced by the actions of neuromodulators such as acetylcholine (ACh). Early studies in anaesthetized cats argued that acetylcholine can cause a sharpening of orientation tuning functions and an improvement of the signal-to-noise ratio (SNR) of neuronal responses in primary visual cortex (V1). Recent in vitro studies have demonstrated that acetylcholine reduces the efficacy of feedback and intracortical connections via the activation of muscarinic receptors, and increases the efficacy of feed-forward connections via the activation of nicotinic receptors. If orientation tuning is mediated or enhanced by intracortical connections, high levels of acetylcholine should diminish orientation tuning. Here we investigate the effects of acetylcholine on orientation tuning and neuronal responsiveness in anaesthetized marmoset monkeys. We found that acetylcholine caused a broadening of the orientation tuning in the majority of cells, while tuning functions became sharper in only a minority of cells. Moreover, acetylcholine generally facilitated neuronal responses, but neither improved signal-to-noise ratio, nor reduced trial-to-trial firing rate variance systematically. Acetylcholine did however, reduce variability of spike occurrences within spike trains. We discuss these findings in the context of dynamic control of feed-forward and lateral/feedback connectivity by acetylcholine.