Svara (nostril dominance) and bilateral volar GSR.

The Svara yoga concept of Ida, Pingala and Susumna svara representing rest, active and turbulent states was examined in this study by recording nostril dominance (svara) and bilateral volar GSR (galvanic skin resistance) as an indicator of sympathetic activity under field and laboratory conditions. The sympathetic activity was low in Ida svara, followed by Pingala svara and was maximum in Susumna svara group of subjects under both field and laboratory conditions which agreed with the traditional Svara yoga description. The volar GSR on the right side more readily varied with svara, particularly so in the physically relaxed subjects of laboratory condition than the left volar GSR. The latter observation was worth noting because the subjects were right handed. The right side could be recommended as the standard site for recording volar GSR to closely reflect the sympathetic activity, particularly so when physical rest was given to subjects.

Reflex reversal of nostril dominance by application of pressure to the axilla by a crutch.

Effect of pressure application by a crutch to the axilla of the side of the dominant right nostril on the pattern of nostril dominance with emphasis on the time sequence of changes and recovery was studied in the young male Nigerians. The nostril dominance was assessed from the percentage of tidal volume flowing through the right and left nostril passages during expiratory phase (7). Application of pressure to right axilla for 20 min caused tidal volume flowing through left nostril to change from the control value of 20.3 +/- 15.8% (SD) to 74.1 +/- 10.4% while the rest of the tidal volume passed through the right nostril. The effect started in the first minute; air flow through both nostrils was equalized by 4 min; reversal of nostril dominance occurred thenceforth; and peak change was obtained by 17 min after application of pressure to the axilla. Removal of crutch could not lead to recovery.

Reversal of nostril dominance by posture.

Reflex reversal of differential air flow through nostrils (DAFTN) by the adoption of suitable lateral recumbent position was studied in male Nigerian subjects. The subjects who demonstrated more air flow through the left nostril initially in the supine position, adopted left lateral recumbent (LLR) position which brought the decongested left nostril to the down-side and the congested right nostril to the upside. Within 3 to 4 minutes after the adoption of LLR position, the air flow through the nostrils was equalised and by 11th minute the DAFTN was reversed, with more air flowing through the upsided right nostril. Return of the subjects to supine position could not result in the recovery to the initial pattern of DAFTN. It is suggested that reversal of DAFTN with adoption of suitable lateral recumbent position was a reflex effect due to the pressure stimuli to the lower lateral side of the body particularly around the shoulder region and effect was mediated through the sympathetic innervation to mucosal venous sinuses of the nostrils. Possibility of gravitational effect was ruled out.

Effect of inspiratory and expiratory air flow on congestion and decongestion in the nasal cycle.

The role of the inspiratory and expiratory airflow through nostrils during the process of breathing in the reflex reciprocal congestion and decongestion of the nasal cycle was examined in this study. Air flow through each nostril was measured separately in male subjects before and after four types of breathing practices for 15 min each consisting of (1) inspiration through the patent nostril and expiration through the congested nostril, (2) inspiration through congested nostril and expiration through patent nostril, (3) inspiration through both nostrils and expiration through mouth and (4) inspiration through mouth and expiration through both nostrils. The breathing practices had no effect on the congested nostril but caused decrease in air flow through the patent nostril, indicating congestion. It is suggested that the inspiratory and expiratory air flow through the nostrils caused reflex congestion of the patent nostril. The stimuli arising from the nasal mucosa due to air flow during breathing may form the basis for the reflex reciprocal congestion and decongestion of nostrils in the nasal cycle.