[Solved] African naked mole rats show no behavioral response when exposed to capsaicin, the active ingredient in chili peppers. This is most likely due to the fact that they lack the neurotransmitter A) glutamate. B) GABA . C) substance P. D) serotonin. Neurotransmitters: Chemical substances that transmit signals across a synapse from one neuron to another in the nervous system. Sciatic Nerve: The largest nerve in the human body, running from the lower back down through the buttock and into the lower limb, responsible for sensation and movement in the leg. Phagocytes: Cells within the body capable of engulfing and absorbing bacteria and other small cells and particles. Meninges: Three protective membranes that surround the brain and spinal cord.