In mammals, physical vibrations in the environment are sensed by Pacinian corpuscles, which in mice forelimbs are located in deep tissue next to bones. Activation of these receptors triggers responses in the primary somatosensory cortex (S1). Two-photon imaging of the responses of layer 2/3 neurons in the contralateral forelimb S1 to a high-frequency vibrational stimulus showed that S1 spike rates were selectively tuned to stimulus features and specific combinations of frequency and amplitude of vibration. S1 encoding of high-frequency vibration frequency is similar to sound pitch representation in auditory cortex.
Prsa, M. et al. Feature-selective encoding of substrate vibrations in the forelimb somatosensory cortex. Nature 567, 384–388 (2019)