Flamming brown pipette puller

An optogenetic-microdialysis probe with a 125 μm-diameter optic fiber (0.22 numerical aperture) embedded in a microdialysis probe was used for optogenetic stimulation of glutamate release by cortico-striatal terminals (Quiroz et al., 2016a (link); Yepes et al., 2017 (link)). The tip of the optic fiber was given a conical shape to allow a local light dispersion through and around the working portion of the dialyzable membrane. The conical sculpted tip with the cladding fused to the core was obtained by pulling the fiber with a Flamming-Brown pipette puller (Sutter Instruments, Novato, CA), fitted with a custom platinum heating filament of circular cross-section (1 mm in diameter) and a holder specifically designed for the diameter of the optic fiber. Optical stimulation was delivered coupling the light guiding port of the implanted optogenetic-microdialysis probe to a 473-nm solid-state laser module driven by an electrical stimulator (Grass S88 stimulator). Light pulses were applied over a 20-min period in 160-ms trains of 1-ms pulses at a frequency of 60 or 100 Hz and intensity of 5–8 mW at the probe tip (one train/s). Light intensity at the probe tip was measured before implantation using an integrating sphere silicon photodiode power sensor designed for optical power measurements independent of beam shape and divergence (model S144C, Thor Labs, Newton, NJ).

An optogenetic-microdialysis probe with a 125 μm-diameter optic fiber (0.22 numerical aperture) embedded in a microdialysis probe was used for optogenetic stimulation of glutamate release by cortico-striatal terminals^{21 (link)}. The tip of the optic fiber was given a conical shape to allow a local light dispersion through and around the working portion of the dialyzable membrane. The conical sculpted tip with the cladding fused to the core was obtained by pulling the fiber with a Flamming-Brown pipette puller (Sutter Instruments, Novato, CA), fitted with a custom platinum heating filament of circular cross-section (1 mm in diameter) and a holder designed for the small diameter of the optic fiber. Optical stimulation was delivered coupling the light guiding port of the implanted optogenetic-microdialysis probe to a 473-nm solid-state laser module driven by the electrical stimulator (Grass S88 stimulator). Light was applied over a 20-min period in 160-ms trains of 1-ms pulses at 100 Hz at 5–8 mW at the probe tip (one train/s). Light intensity at the probe tip was measured before implantation using an integrating sphere silicon photodiode power sensor designed for optical power measurements independent of beam shape and divergence (model S144C, Thor Labs, Newton, NJ).