An optogenetics device with smartphone video capture to introduce neurotechnology and systems neuroscience to high school students

Abstract

Although neurotechnology careers are on the rise, and neuroscience curriculums have significantly grown at the undergraduate and graduate levels, increasing neuroscience and neurotechnology exposure in high school curricula has been an ongoing challenge. This is due, in part, to difficulties in converting cutting-edge neuroscience research into hands-on activities that are accessible for high school students and affordable for high school educators. Here, we describe and characterize a low-cost, easy-to-construct device to enable students to record rapid Drosophila melanogaster (fruit fly) behaviors during optogenetics experiments. The device is generated from inexpensive Arduino kits and utilizes a smartphone for video capture, making it easy to adopt in a standard biology laboratory. We validate this device is capable of replicating optogenetics experiments performed with more sophisticated setups at leading universities and institutes. We incorporate the device into a high school neuroengineering summer workshop. We find student participation in the workshop significantly enhances their understanding of key neuroscience and neurotechnology concepts, demonstrating how this device can be utilized in high school settings and undergraduate research laboratories seeking low-cost alternatives.

Fig 1. A low-cost optogenetics device.

(A) Top view of the device mounted on a standard stereoscope. The eyepieces of the stereoscope were inserted into the sleeves of the Stereoscope Camera Mount. A smartphone was fixed in place on the Stereoscope Camera Mount, with the camera aligned to the eyepiece and the display clearly visible to the students. The Motion Sensor Module was located on the left side of the Stereoscope Camera Mount to detect finger movements. (B) The cardboard Stereoscope Camera Mount. Dimensions can be found within the technical drawing of S1 Fig. (C) Schematic representation of a tethered Drosophila. UV glue connects one end of a tungsten wire to the notum of the Drosophila. The other end of the tungsten wire is inserted into a piece of clay for positioning and stabilization. (D) Side view of the device mounted on a standard stereoscope, that includes the position of the tethered Drosophila in front of the Optogenetic Stimulation LED Module. The Arduino Development Board depicted in this figure has a shield that replaces the role of an ordinary protoboard. (E) Component diagram for the device. The Arduino Development Board controls the Connected Switch Module, Status LED Module, Board LED Module, Optogenetic Stimulation LED Module, and Motion Sensor Module necessary for the experiments. Modules depicted with double-sided arrows communicate to and from the Arduino for proper module function. The Stereoscope Camera Mount houses both the Motion Sensor Module and a user’s smartphone.

Fig 2. The optogenetics device replicates prior GF activation studies.

(A) Annotated response of optogenetic GF activation shows the fly holding a small piece of a Kimwipe before light stimulation, followed by subsequent leg extension, wing depression, and flight initiation after light stimulus presentation. (B) Percentage of escapes across genotypes (n = flies as stated in figure, χ2 test, P << .001, Bonferroni correction post hoc, *** = p < .001). Abbreviations: retinal food (+), standard food (-), GF-split-GAL4 (GF), Canton S wild type (WT), UAS-CsChrimson (CsChr).

Fig 3. The optogenetics device replicates prior freezing neuron activation studies.

(A) Annotated response of optogenetic activation of the freezing line shows the fly moving its legs before light stimulation, freezing during and after light stimulation, and then returning to leg motion (B) The percentage of flies that freeze with light stimulation (n = flies as stated in figure, χ2 test, P << .001, Bonferroni correction post hoc, *** = p < .001). Abbreviations: retinal food (+), standard food (-), SS1540-split-Gal4 (SS1540) CSMH wild type (WT), UAS-CsChrimson (CsChr).

Fig 4. Workshop assessment outcomes.

A total of 47 students distributed over three workshops were evaluated on four concepts, both before and after the workshop. Gray connected boxes indicate individual student scores and red squares indicate averages (Wilcoxon signed rank test, *** = p<<0.001). Abbreviations: quiz administered before the workshop (B); quiz administered after the workshop (A).