International Journal of Psychophysiology 52 (2004) 211–216 0167-8760/04/$ - see front matter  2003 Elsevier B.V. All rights reserved. doi:10.1016/j.ijpsycho.2003.10.004 Short communication Photo-acoustic stimulation increases the amount of 70 kDa heat shock protein (Hsp70) in human whole saliva. A pilot study Tibor Karoly Fabian , Zsuzsanna Toth , Laszlo Fejerdy , Borbala Kaan , Peter Csermely *, a a a a b, ´ ´ ´ ´ ´ ´ ´ ´ ´ ´ Pal Fejerdy a ´ ´ Faculty of Dentistry, Semmelweis University, Clinic of Prosthetic Dentistry H-1088 Budapest, Mikszath Kalman square 5, a ´ ´ ´ Budapest, Hungary Faculty of Medicine, Institute of Medical Chemistry, Semmelweis University, H-1444, Budapest 8 P.O. Box 260, Hungary b Received 19 June 2003; received in revised form 3 July 2003; accepted 22 October 2003 Abstract Long-term photo-acoustic stimulation leads to changes in the composition of saliva, which may have a key contribution to the effectivity of this technique in easing mucosal symptoms of psychosomatic patients. In the present study a significant (PF0.01) increase in salivary 70 kDa heat shock protein, Hsp70 was demonstrated in human whole saliva after repeated photo-acoustic stimulation. Increased salivary chaperones may contribute to the effectivity of photo-acoustic stimulation, because of their cytoprotective extracellular actions.  2003 Elsevier B.V. All rights reserved. Keywords: Chaperone; Hsp70; Mucosal; Saliva; Extracellular; Photo-acoustic stimulation; Human 1. Introduction Previous studies demonstrated the strong effect of short run photo-acoustic stimulation on the central nervous system. Berger (1930) demonstrat- ed a decreasing effect of photic stimulation on the amplitude of alpha waves on EEG. Similarly, an occipital decrease of alpha density (average of alpha wave’s amplitude) has been found by Kawa- bata (1972) using a 10 Hz frequency flash light stimulus or a confluent stimulus for 2 s on closed eyes. These effects have been called ‘light on *Corresponding author. Tel.: q36-1-266-2755x4102; fax: q36-1-266-7480. E-mail address: csermely@puskin.sote.hu (P. Csermely). effects’. The same effect have been found by him when he turned the 2 s light off. This effect has been called as ‘light off effect’. Aranibar and Pfurtscheller (1978) published results about the positive correlation between the ‘on’ effect and the intensity of the stimulus, and about the specific sensor modality of the ‘on’ and ‘off’ effects. These effects were more effective in the occipital region of the brain in the case of photic stimulation, and in the centric region of the brain in the case of the acoustic one. All above data indicate an effective stimulation of the central nervous system by a short photo-acoustic treatment. In contrast, long lasting photo-acoustic stimulation leads to sleepi- ness, and to a mixed alpha–theta activity of the