Data_Sheet_1_Adrenergic Modulation of Visually-Guided Behavior.PDF

Iontophoretic application of norepinephrine (NE) into the primary visual cortex (V1) in vivo 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 in vivo 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 α1- 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）通过电渗法应用于活体小鼠初级视觉皮层（V1），能够显著降低其自发性及诱发性活动，而不会影响皮层单元的功能选择性。此现象的可能后果之一是，肾上腺素能受体（ARs）调节了该回路中神经反应的信噪比（SNR）。然而，尽管去甲肾上腺素对V1神经元放电模式的抑制作用十分强烈，但其对视觉行为的具体作用尚未得到研究。此外，关于皮层NE的多数观察均是在麻醉动物中通过活体记录进行的，且尚未在行为学上进行验证。在本研究中，我们描述了将AR激动剂/拮抗剂微注射入小鼠V1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，α1-和β-AR在皮层的激活导致在高对比度和低空间频率下视觉辨别能力的显著下降，这与分割效应相一致。这种下降是可逆的，并伴随着逃避潜伏期的增加以及随刺激对比度变化的组平均选择方差的增加。我们得出结论，通过视觉反应的分割增益控制，皮层AR的药理学激活调节了视觉感知和适应性行为。