Dept. of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
J Neurophysiol. 2012 Feb;107(3):758-65. doi: 10.1152/jn.00609.2011. Epub 2011 Nov 2.
To understand how activity in mammalian neural circuits controls behavior, the mouse is a promising model system due to the convergence of genetic, optical, and physiological methods. The ability to control and quantify behavior precisely is also essential for these studies. We developed an operant visual detection paradigm to make visual psychophysical measurements: head-fixed mice make responses by pressing a lever. We designed this task to permit neurophysiological studies of behavior in cerebral cortex, where activity is variable from trial to trial and neurons encode many types of information simultaneously. To study neural responses in the face of this complexity, we trained mice to do a task where they perform hundreds of trials daily and perceptual thresholds can be measured. We used this task to measure both visual acuity and the minimum detectable contrast in behaving mice. We found that the mouse contrast response function is similar in shape to other species. They can detect low-contrast stimuli, with a peak contrast threshold of 2%, equivalent to ∼15° eccentric in human vision. Mouse acuity is modest, with an upper limit near 0.5 cycles/°, consistent with prior data.
为了理解哺乳动物神经回路的活动如何控制行为，由于遗传、光学和生理学方法的融合，老鼠是一个很有前途的模型系统。精确控制和量化行为的能力对于这些研究也是必不可少的。我们开发了一种操作性视觉检测范式来进行视觉心理物理学测量：头部固定的老鼠通过按下杠杆来做出反应。我们设计了这个任务，以便在大脑皮层中进行行为的神经生理学研究，在大脑皮层中，活动在每次试验中都有变化，神经元同时编码多种类型的信息。为了研究面对这种复杂性的神经反应，我们训练老鼠每天进行数百次试验，并可以测量感知阈值。我们使用这项任务来测量行为老鼠的视觉敏锐度和最小可检测对比度。我们发现，老鼠的对比度反应函数与其他物种相似。它们可以检测低对比度的刺激，对比度阈值峰值为 2%，相当于人类视觉中的 15°偏心。老鼠的视力适中，上限接近 0.5 个/°，与之前的数据一致。
