determined that the threshold by which the star-like structure senses the mechanical stimuli depends on which type of the Eimer’s organ was excited. He characterized three main classes of Eimer’s receptors, including one of slow adaptation (Tonic receptor) and two of rapid adaptation (Phasic receptor). The tonic receptor has a response similar to that of a Merkel cell-neurite complex. It has free terminals and is therefore able to detect pressure and texture with a high sensitivity and at a Random Sustained Discharge. The rapid adapting responses include a Pacinian-like response based on an (on-off) response caused by pressure and mechanical vibrations with maximum sensitivity to stimuli at a frequency of 250 Hz. The differences between both rapid responses rely on the fact that one of them only has a response during the compression phase. Frequency sensitivity Among the receptors described, Marasco identified that there were receptors relatively unresponsive to compressive stimuli but were acutely responsive to any kind of stimulus that brushed or slid across the surface of the nose (Stimuli applied with large displacements and high velocity). In contrast, there were other receptors that responded robustly to small magnitude compression of any kind but were not responsive to sweeping stimuli. The receptors that were sensitive to sweeping were maximally activated across a broad range of frequencies from 5–150 Hz at large displacements ranging from 85–485 μm. Conversely, the receptors that respond to compressive stimuli showed a narrow peak of maximal activity at 250–300 Hz with displacements from 10–28 μm. Directional sensitivity Based on the circular organization of the nerve endings and its innervation pattern in Eimer’s organs, Marasco proposed by mapping experiments that nearly all receptors in the star-nosed mole have a preference for a particular direction of applied stimuli. Thus, while one receptor elicits a strong response if compressed in one direction, it may stay "silent" when compressed in another one. Velocity sensitivity Examination of the threshold of velocity at which the receptors responded identified that the minimum velocity of cell response was 46 mm/s, corresponding to the approximate speed of the nose during foraging behavior. Transduction of the mechanical signal Taking into account that Eimer’s organ senses mechanical deformation, its mechanism of transduction can be explained in a few steps: Stimuli cause depolarization of the receptor membrane, resulting in a receptor potential and therefore a current towards the node of Ranvier. If the receptor potential is maintained