Observation of single-sweat-gland activities by an improved electrical conductivity measurement technique

It was reported by Shamsuddin el al [1] that sweating from a sweat gland could be continuously recorded using a technique in which ion-free sucrose solution was perfused onto a small region of the skin, and the secreted sweat detected by the change in electrical conductivity. We have improved the technique of Shamsuddin et al., and have developed a system that can record sweating from up to four independent sweat glands simultaneously. Using the technique, we have observed differences in the sweat response of different sweat glands on the palms of 11 subjects subjected to applied physical or mental stresses. Simultaneous recordings from two or more sweat glands were obtained in all subjects, and in three subjects, sweating from four sweat glands was recorded repeatedly. In most observations, the sweat responses recorded from different sweat glands were different in amplitude and in waveform. However, similar sweat response patterns were occasionally observed. From this, we suspect that the sweat response depends on the nervous control of the sweat gland, and that sweat glands under the same nervous control exhibit quite similar sweat responses.