The globus pallidus (GP) is a subcortical structure of the human brain. This structure is composed of both external and internal circuits, known as GPe and GPi, respectively. The article, “Targeting Circuits with DBS,” published October 29th, 2021, by Nature Reviews Neuroscience, details the findings of Spix et al., who have conducted multiple highly detailed studies on neuronal populations to determine which ones should be targeted with advanced DBS technology. In their initial study they found that optogenetic activation of parvalbumin-expressing (PV+) neurons and inhibition of LIM homeobox protein 6-expressing (LHX6+) neurons “reduced circuit dysfunction and motor deficits in dopamine-depleted mice several hours after stimulation.” This finding reveals an interesting commentary on the effects that PV+ neurons have on motor function and LHX6+ neurons have on motor dysfunction.
Using the trend noted above, Spix et al. used bursts of DBS, which were implanted into neuronal populations, PV+ and LHX6+, of the GPe, to activate PV+ neurons and inhibit LHX6+ neurons. What they found was that compared to conventional DBS, which stimulates the subthalamic nucleus (STN), thalamus (VIM), and globus pallidus interna (GPi) depending on which symptoms are most prevalent in the Parkinson’s Disease (PD). Implanted DBS devices are becoming ever-more important in the fight against the tremors, slowness, rigidity, dystonia (involuntary muscle contraction) and dyskinesia (muscle jerking) caused by PD.