Opt Lett. 2024 Oct 15;49(20):5909-5912. doi: 10.1364/OL.537449.
Long-term and non-narcotic hemodynamic imaging is indispensable for observing factual physiological information of the spinal cord. Unfortunately, achieving label-free, high-resolution, and widefield spinal cord imaging for mice under freely moving conditions is challenging. In this study, we developed a miniaturized photoacoustic microscope along with a corresponding photoacoustic spinal window to realize high-resolution, multi-segmental hemodynamic imaging of the spinal cord for freely moving mice. The microscope has an outer size of 32 mm × 23 mm × 10 mm, a weight of 5.8 g, and a 4.4 µm lateral resolution within an effective field of view (FOV) of 2.6 mm × 1.8 mm. To eliminate the off-focus phenomena during spinal imaging, the microscope is equipped with a miniature motor to adapt the focal plane. Besides, the microscope is slidable along a customized rail on the window to expand the FOV. We evaluated the stability of the microscope and analyzed vascular images of the spinal cord under various physiological states. The results suggest that the microscope is capable of performing stable, multi-segmental spinal cord imaging in freely moving mice, offering new insights into spinal cord hemodynamics and neurovascular coupling research.
长期的、非成瘾性的血流动力学成像是观察脊髓真实生理信息所必不可少的。遗憾的是，在自由活动的条件下，实现对小鼠的无标记、高分辨率、宽视场的脊髓成像极具挑战性。在本研究中，我们开发了一种微型化光声显微镜，并结合相应的光声脊髓窗，实现了用于自由活动小鼠的高分辨率、多节段脊髓血流动力学成像。该显微镜的外部尺寸为 32mm×23mm×10mm，重量为 5.8g，在 2.6mm×1.8mm 的有效视野内具有 4.4μm 的横向分辨率。为了消除在脊髓成像过程中的离焦现象，显微镜配备了一个微型电机以适应焦平面。此外，显微镜可沿窗口上的定制轨道滑动以扩展视野。我们评估了显微镜的稳定性，并分析了在各种生理状态下的脊髓血管图像。结果表明，该显微镜能够在自由活动的小鼠中进行稳定的、多节段的脊髓成像，为脊髓血流动力学和神经血管耦合研究提供了新的见解。
