Extended Data Fig. 9: Behavior tracking of spinally fixed mice and freely moving spinal cord imaging with miniature microscopes.
From: Long-term optical imaging of the spinal cord in awake behaving mice
a, Visibly opaque (black) infrared transmitting acrylic allows imaging of animal behavior using near-IR light sources and cameras, while blocking animal observation of experimenters (for example during stimulus delivery). b, Model error as a function of DeepLabCut iterations for a model trained using data from one mouse for each camera. Model training is terminated after 500,000 iterations, when the loss asymptotes. c, Part affinity fields for DeepLabCut networks across multiple cameras. d, Speed of individual body parts shows correlation of body part movement across cameras (#1–4). The mean speed across all cameras for each body part is used for display in Fig. 5g. Camera locations correspond to 1, left side of the body; 2, right side of the body; 3, right face; and 4, below the animal. Letters below each black arrow indicate the stimulus presented (C: cold; P: pinch; H; heat; A: air puff; S: sound); black bar denotes duration of the sound stimuli. e, 3D CAD of miniature microscope positioning above spinal implant chamber. f, Image of miniature microscope mounting (Inscopix, nVista). g, Image of miniature microscope mounting (Open Ephys, Miniscope V4.4). h, View of dorsal vein after procedure in g. Scale bar, 200 µm. i, Image of miniature microscope mounting in an awake animal (Inscopix, LScape module for nVue 2.0). j, Image of a miniature microscope mounted on the mouse using a clamp. k, Example of normal grooming behavior. l, Field of view from mouse in k. Scale bar, 200 µm. m, Ambulating mouse after mounting procedure in g. n, Locomotion of a mouse moving freely in an open field during spinal cord imaging (30 min, 10 Hz). Scale bar, 10 cm. o, Locomotor trace during the open field session in n. p, Multi-color miniature microscope imaging of both sides of the spinal cord 70 days after window placement in a Phox2a-Cre; Ai162 (GCaMP6s); Ai9 (tdTomato). Scale bar, 300 µm. q, Responses of SCPNsPhox2a (Phox2a-Cre; Ai162 [GCaMP6s]) to cold, hot, and air puff stimuli delivered to the left hindpaw during a ~1.8-hr continuous imaging session. Max projection of 5 s post-stimulus. Scale bar, 300 µm.
