Activation patterns of different brain areas during incremental exercise measured by near-infrared spectroscopy

Abstract

Recent studies postulated that increased oxygenation of the prefrontal cortex (PFC) during elevating exercise intensities reflects a specific activation of this region. Furthermore, the drop in PFC oxygenation often measured shortly before exhaustion is interpreted as a main factor limiting exercise. Nevertheless, a limitation of these studies is that they often measured NIRS only in the PFC. Within this study, we hypothesized that these findings are not region specific but rather result from systemic blood redistribution to the working skeletal muscle. NIRS was measured in three different brain regions and the working skeletal muscle during incremental cycling till exhaustion in nine healthy men. Oxygenated hemoglobin of the PFC increased from low to submaximal intensities and leveled off at maximal intensities. There was no drop in PFC oxygenation before exercise abortion. Interestingly, the occipital cortex was unaffected during exercise, while the motor cortex showed an increasing deoxygenation with elevating exercise intensities, just as observed in the skeletal muscle. In conclusion, this study does not support the notion that PFC deoxygenation is involved in the limitation of maximum exercise capacity. Against the hypothesis, the NIRS signals of the other cortices differed clearly, indicating that the previously reported findings indeed represent region-specific activations.

Self-reported tolerance influences prefrontal cortex hemodynamics and affective responses

“…In the present study, no decline in cerebral oxygenation was observed at a similar intensity; instead, cerebral oxygenation increased in the high-tolerance and remained stable in the low-tolerance group. The lack of a drop in PFC oxygenation near exhaustion has recently been observed by others (Jung et al, 2015). A potential explanation of this discrepancy is that it may be due to differences in the placement of the optodes over the PFC (Jung et al, 2015), since prior work has shown region-specific changes in PFC hemodynamics (Tempest, Eston, & Parfitt, 2014).…”

“…The lack of a drop in PFC oxygenation near exhaustion has recently been observed by others (Jung et al, 2015). A potential explanation of this discrepancy is that it may be due to differences in the placement of the optodes over the PFC (Jung et al, 2015), since prior work has shown region-specific changes in PFC hemodynamics (Tempest, Eston, & Parfitt, 2014). Finally, both males and females took part in this study, and no gender effects were observed (other than those likely explained by fitness).…”

“…At this intensity, an individual's ability to maintain PFC activation becomes threatened. Recent work, using electroencephalography (EEG; Robertson & Marino, 2015) and near infrared spectroscopy (NIRS; Jung, Moser, Baucsek, Dern, & Schneider, 2015), has shown a redistribution of brain activation in PFC and motor regions as the intensity of exercise is increased. Since exercise influences PFC activation, it may be used to manipulate sensory input from the body (presumably to the amygdala) in order to examine the role of the PFC in the regulation of affective responses.…”

Physiological and psychological determinants of whole-body endurance exercise following short-term sustained operations with partial sleep deprivation

“…However, considering that NIRS measurements reflect but region-specific oxygenation changes, we cannot exclude that other brain areas, critically involved in strenuous exercise (cf. Jung et al 2015), were affected by SUSOPS.…”

A comparison of head motion and prefrontal haemodynamics during upright and recumbent cycling exercise

“…Near infrared spectroscopy (NIRS) is commonly used to examine the cerebral haemodynamic response (oxygenation [O 2 Hb; oxygen delivery], deoxygenation [HHb; oxygen extraction] and total blood volume [tHb = O 2 Hb + HHb]) during exercise (Ferrari & Quaresima, ). Many studies focus largely upon prefrontal areas of the brain during exercise in healthy (Shibuya et al ., ; Bhambhani et al ., ; Hiura et al ., ; Rupp et al ., ; Tempest et al ., ; Jung et al ., ) and clinical populations (Neary et al ., ; Fu et al ., ; Lin et al ., ; Vogiatzis et al ., ). The predominant modes of exercise used in such studies are upright and recumbent cycle ergometers.…”