[Responses of individual receptor units of rat mammary gland parenchyma to tactile stimulation].

Two types of slowly adapting mechanosensitive units were revealed in the parenchyma of the rat mammary gland (SAI and SAII). At constant mechanical displacement of the parenchyma surface SAI exhibited irregular and SAII--regular firing. The diameter of the receptive fields of the SAI and SAII was 1.0--1.5 mm with the central point of this area being the most sensitive. Trapezoidal stimuli elicited both dynamic and static responses proportional to the velocity of the movement and its displacement amplitude; the threshold of the SAI and SAII increased as stimuli of increasing velocity were used.