Transcranial electrostimulation augments physical working capacity

Abstract

Transcranial stimulation using weak electric current with rigidly fixed parameters is shown to prolong the time during which BALB/c and CBA/Lac mice are capable of swimming with a weight attached to their body and to accelerate their recovery after submaximal exercise. The increase in working capacity is blocked by the opioid receptor antagonist naloxone. The use of transcranial electrostimulation to augment adaptive capabilities of the body is discussed. Key Words: transcranial electrostimulation; opioid system; naloxone; working capacityFindings from recent studies enable adequate functioning of the endogenous opioid system (OS) to be regarded as one of the principal mechanisms by which failure of adaptation can be prevented when a stress reaction develops [1,4,5]. This raises the question of whether the adaptive capacity of the body can be increased by stimulation of endogenous OS. One method of such stimulation is transcranial electrostimulation (TCES) with a weak electric current having rigidly fixed parameters [3]. Indeed, the analgesic action of TCES as well as a number of its peripheral effects have been shown to be associated with stimulation of this system [2,3].The foregoing led us to suggest that TCES may be used to enhance adaptive capabilities of the body and, in particular, to increase its physical working capacity during submaximal exercise. The aim of the present study was experimental testing of this hypothesis. MATERIALS AND METHODSMale BALB/c (n=324) and CBA/Lac (n=99) mice weighing 20-25 g were used. They were obtained from the Stolbovaya Nursery of the Russian Academy of Medical Sciences and maintained under standard conditions in the vivarium for 2 weeks preceding the study.TCES was performed in immobilized mice with a modified EA-30-1 Elektronarkon-1 apparatus for electroanesthesia via subcutaneous needle electrodes inserted in the facial part of the skull from the midline of the eyes to the nasal cavity (cathode) and behind the auricular conchae (doubled anode). Control mice underwent the same procedures as did test mice (i.e., were immobilized and had electrodes inserted as described), but were not exposed to electric current. Each TCES session lasted for 30 min using a combination of direct current and rectangular pulses of 70 Hz and 3.0 msec in duration at a 2:1 ratio, the total current being 0.6 mA. While selecting parameters of the current, we took into account the fact that analgesia in rodents of different species occurs at a frequency of 60 or 70 Hz and