bipolar suction electrode  (A-M Systems)

Journal: bioRxiv

Article Title: Mapping of dI3 neuron sensorimotor circuits across the cervical and lumbar spinal cord

doi: 10.1101/2024.11.17.624039

Figure Lengend Snippet: A. Diagram of genetic strategy for generating Isl1 Cre +/- ; Slc17a6 FlpO +/+ ; Ai80 (RCFL-CatCh)-D and Isl1 Cre +/- ; Slc17a6 FlpO +/+ ; Ai65 (RCFL-tdT)-D mice. Isl1 Cre +/- mice were crossed with Slc17a6 FlpO +/+ mice to drive the expression of Cre and FlpO recombinase in dI3 neurons and Vglut2 + nociceptive afferents, forming dI3-driver mice. For optogenetic experiments, Isl1 Cre +/- ; Slc17a6 FlpO +/+ (dI3-driver) mice were crossed with Ai80 (RCFL-CatCh)-D (CatCh) mice containing a frt -flanked STOP cassette and a loxP -flanked STOP cassette upstream of the CatCh/EYFP fluorescent protein, resulting in Isl1 Cre +/- ; Slc17a6 FlpO +/+ ; Ai80 (RCFL-CatCh)-D (dI3-driver-CatCh) mice. To visualize the dI3 neurons and Vglut2 + afferents, dI3-driver mice were crossed with Ai65 (RCFL-tdT)-D (TdTomato) mice containing a frt -flanked STOP cassette and a loxP -flanked STOP cassette upstream of the TdTomato fluorescent protein, resulting in Isl1 Cre +/- ; Slc17a6 FlpO +/+ ; Ai65 (RCFL-tdT)-D (dI3-driver-TdTomato) mice. B. Representative image of TdTomato (red) labelled dI3 neurons and Vglut2 + afferents in dI3-driver-TdTomato mice. To avoid activation of these afferents in dI3-driver-CatCh mice, a dorsal hemisection was performed at the indicated level. C. Diagram of the ex vivo spinal cord preparation. The spinal cord was isolated in neonatal P1-P7 dI3-driver-CatCh mice, and a dorsal hemisection was performed at the cervical (C1-C8) and lumbar (L1-L5) segments to remove Vglut2-CatCh + afferents. Three suction electrodes were simultaneously applied to various ventral roots to record from C4-C8 and L1-L5 segments, and blue light was applied to ipsilateral segments. Within the same animals, blue light was also independently applied to contralateral segments from C4-C8 and L1-L5.

Article Snippet: The micropipette tips were then attached to bipolar suction electrodes (A-M Systems; 573040) and filled to the electrode tip with aCSF before suctioning the roots.

Techniques: Expressing, Activation Assay, Ex Vivo, Isolation

Journal: bioRxiv

Article Title: Mapping of dI3 neuron sensorimotor circuits across the cervical and lumbar spinal cord

doi: 10.1101/2024.11.17.624039

Figure Lengend Snippet: A. Optogenetic stimulation of ipsilateral lumbar dI3s evokes fictive locomotion in flexor and extensor roots. (i) and (iii) Experimental setup and sample locomotor recordings. Spinal cord preparations consisted of isolated lumbar spinal cords from neonatal dI3-driver-CatCh mice with a dorsal hemisection. Suction electrodes were applied to (i) L1 and L4 (red) and (iii) L2 and L5 (blue) roots while optogenetically stimulating ipsilateral L1-L5 segments (L3 not shown). (ii and iv) Blue light was applied for 10 seconds continuously, and alternating, rhythmic activity was observed in both recording electrodes during the stimulation period.

Article Snippet: The micropipette tips were then attached to bipolar suction electrodes (A-M Systems; 573040) and filled to the electrode tip with aCSF before suctioning the roots.

Techniques: Isolation, Activity Assay