Journal: Scientific Reports

Article Title: Optogenetic stimulation of striatal patches modifies habit formation and inhibits dopamine release

doi: 10.1038/s41598-021-99350-5

Figure Lengend Snippet: Characterizing optogenetic patch stimulation on striatal dopamine release. ( a ) Experimental design. Sepw1 NP67 mice were injected with AAV5 driving Cre-dependent expression of ChR2-eYFP. Fast-scan cyclic voltammetry was used to monitor real-time changes in dopamine levels in striatum. An electrical stimulating electrode was placed in the pedunculopontine nucleus (PPTg) to drive increases in dopamine in the dorsal striatum. A fiber optic was placed above patch terminals in the substantia nigra pars compacta (SNc). Electrical or optogenetic or both stimulation types were randomly selected and delivered a minimum of three times each (see Methods). ( b ) (left) Representative recording of electrical stimulation of PPTg. Here, a line shows recorded current relative to stimulation delivery (straight line below current trace) above a pseudo-color plot. The color plot shows current collected (in color) at each waveform scan (y-axis) and across time (x-axis). INSET: a “cyclic voltammogram” collected at the vertical white dotted line on the pseudo-color plot suggesting that dopamine is the predominant analyte being monitored. (right) Same as left, but optogenetic stimulation of patch terminals occurs simultaneously with PPTg electrical stimulation. ( c ) Average responses across replicates for each of the three stimulation types. PPTg stimulation only denoted as E Stim, optogenetic stimulation of patch terminals as Opto. ( d ) Maximum recorded current during stimulation normalized to electrical PPTg stimulation. ( e ) Average cyclic voltammogram across replicates for each stimulation type. * p < 0.05; ** p < 0.01; *** p < 0.001; error bars, SEM. ( a ) drawn in Illustrator CC 2019 (Adobe).

Article Snippet: A twisted bipolar stimulating electrode (Plastics One, Roanoke, VA, USA) connected to a DS4 Biphasic Constant Current Stimulus Isolator (Digitimer) was lowered in 0.1-mm increments starting at − 1.5 DV into PPTg until robust dopamine increases were detected in the dorsal striatum.

Techniques: Injection, Expressing