Design, fabrication and validation of a low-cost stereotaxic device for brain research in rodents

Environmental toxicants can impact brain health and function. Studying their effects on the rodent brain is paramount to understanding the mechanisms and devising therapies. The stereotaxic device is widely used to target brain regions. However, the cost of this device is very high and cannot be afforded by researchers from low- and low-middle-income countries. This study has modelled, designed, fabricated, and evaluated a cost-effective stereotaxic device. A 3-D model of the stereotaxic device was prepared using FUSION 360 software followed by fabrication using aluminium and steel. The aluminium has malleability, lightweight, high extrudability, and corrosion resistance property, making it the material of choice for fabricating the nose clamp, mouth restrainer, and ear bar. To construct the parts requiring motion, we used alloy steel, which has high density, tensile strength and smooth texture. To achieve better accuracy, computer numerical control (CNC) and an automatic wire-cutting (EDM) manufacturing processes were used in fabrication. Later, the dye microinjection and electrolytic lesion techniques were used to validate this instrument. A comparison of percent accuracy for hitting structures between the fabricated and commercial stereotaxic devices for both the deep and superficial brain structures such as the substantia nigra (91.7 vs. 92.5%), thalamus (92.6 vs. 98.22%) and hippocampus (92.85 vs. 98.75%), showcased comparable accuracies between devices. The cost of the materials used were approximately nine thousand Indian rupees, and the labour charges for different machining processes used were approximately seventeen thousand Indian rupees. Totalling to 26,000 Indian rupees or 310 US dollars. This cost may vary depending on the material type/vendor as well. The materials can be provided to a workshop, and the design reported here can be used to make a stereotaxic device for rodent research. The 3-D modeling approach presented here coupled with computerised numerical control/electronic discharge machining process achieves high precision comparable to a commercial product and is also affordable. This study will enable students/researchers in middle and low-income countries to perform neuroscience/toxicological studies on the brain using this self-made low-cost precision device.