Treviño Mario, Medina-Coss Y León Ricardo, Lezama Elí
Laboratorio de Plasticidad Cortical y Aprendizaje Perceptual, Instituto de Neurociencias, Universidad de Guadalajara, Guadalajara, México.
Front Synaptic Neurosci. 2019 Mar 20;11:9. doi: 10.3389/fnsyn.2019.00009. eCollection 2019.
Iontophoretic application of norepinephrine (NE) into the primary visual cortex (V1) reduces spontaneous and evoked activity, without changing the functional selectivity of cortical units. One possible consequence of this phenomenon is that adrenergic receptors (ARs) regulate the signal-to-noise ratio (SNR) of neural responses in this circuit. However, despite such strong inhibitory action of NE on neuronal firing patterns in V1, its specific action on visual behavior has not been studied. Furthermore, the majority of observations regarding cortical NE from recordings have been performed in anesthetized animals and have not been tested behaviorally. Here, we describe how micro-infusion of AR agonists/antagonists into mouse V1 influences visually-guided behavior at different contrasts and spatial frequencies. We found that cortical activation of α- and β-AR produced a substantial reduction in visual discrimination performance at high contrasts and low spatial frequencies, consistent with a divisive effect. This reduction was reversible and was accompanied by a rise in escape latencies as well as an increase in the group averaged choice variance as a function of stimulus contrast. We conclude that pharmacological activation of cortical AR regulates visual perception and adaptive behavior through a divisive gain control of visual responses.
将去甲肾上腺素（NE）离子导入初级视觉皮层（V1）可降低自发活动和诱发活动，而不改变皮层神经元的功能选择性。这种现象的一个可能结果是，肾上腺素能受体（ARs）调节该神经回路中神经反应的信噪比（SNR）。然而，尽管NE对V1区神经元放电模式有如此强烈的抑制作用，但其对视觉行为的具体作用尚未得到研究。此外，大多数关于皮层NE的记录观察都是在麻醉动物身上进行的，并未进行行为测试。在此，我们描述了将AR激动剂/拮抗剂微量注入小鼠V1区如何影响不同对比度和空间频率下的视觉引导行为。我们发现，α-AR和β-AR的皮层激活在高对比度和低空间频率下会导致视觉辨别性能显著下降，这与一种分裂效应一致。这种下降是可逆的，同时逃避潜伏期延长，并且随着刺激对比度的变化，群体平均选择方差增加。我们得出结论，皮层AR的药理学激活通过对视觉反应的分裂增益控制来调节视觉感知和适应性行为。
