Alekseev N P, Velling V A, Grachev I I
Fiziol Zh SSSR Im I M Sechenova. 1975 May;61(5):738-43.
Three types of the mechanosensitive units were found in the skin of the rat mammary gland nipple: receptors detecting: 1) transients, 2) velocity, 3) position and velocity. The 1st and the 2nd types were spontaneously inactive and both adapted rapidly to mechanical stimuli. The 3rd type had a spontaneous activity 1-4/sec and adapted slowly to mechanical stimuli.