scholarly journals Influence of nicotine upon human brain metabolism, an in vivo noninvasive Near Infrared Spectroscopy (NIRS) study

2021 ◽  
Vol 4 (4) ◽  
pp. 01-07
Author(s):  
Francesco Crespi

Nicotine, a natural alkaloid derived from tobacco, is involved in various outcomes ranging from addiction to toxicity and/or neuro-protective actions. Nevertheless, the literature on the effects of nicotine administration upon the activity of brain regions is mixed; either increased, decreased, or no overall effect was reported when being evaluated by various methodologies such as positron emission tomography (PET), functional Magnetic Resonance Imaging (fMRI). In this work, Near Infrared Spectroscopy (NIRS) is applied as it allows monitoring oxygen saturation in the living tissue as well as changes in oxygenation of hemoglobin and when applied on brain studies, it gives indications of cerebral haemo-dynamics as well as brain metabolism. In particular, here NIRS has been applied in human volunteers as this methodology is based upon the use of harmless radiations so that to provide a non-invasive, non-ionizing procedure to monitor 2 main forms of hae­moglobin: oxy-haemoglobin (HbO2) and deoxy-haemoglobin (Hb). The data gathered indicate an overall positive influence of nicotine upon HbO2 levels, as well as total blood volume (V) therefore suggesting an increased brain metabolism. Finally these data further propose NIRS with its characteristics of noninvasiveness, easy to-use, portable, restraint-free therefore relatively psychologically undemanding, as replicable and ideal methodology for clinical applications and translational approaches.

2019 ◽  
Vol 9 (11) ◽  
pp. 2366 ◽  
Author(s):  
Laura Di Sieno ◽  
Alberto Dalla Mora ◽  
Alessandro Torricelli ◽  
Lorenzo Spinelli ◽  
Rebecca Re ◽  
...  

In this paper, a time-domain fast gated near-infrared spectroscopy system is presented. The system is composed of a fiber-based laser providing two pulsed sources and two fast gated detectors. The system is characterized on phantoms and was tested in vivo, showing how the gating approach can improve the contrast and contrast-to-noise-ratio for detection of absorption perturbation inside a diffusive medium, regardless of source-detector separation.


2021 ◽  
Author(s):  
Yoko Hasegawa ◽  
Ayumi Sakuramoto ◽  
Joe Sakagami ◽  
Masako Shiramizu ◽  
Tatsuya Suzuki ◽  
...  

Abstract Evidence indicates that distinct brain regions are associated with various emotional states. Cortical activity may be modulated by emotional states that are triggered upon chewing with various flavors. We examined cortical activity during chewing with different tastes/odors using multi-channel near-infrared spectroscopy (NIRS). Thirty-six right-handed subjects participated in a crossover-design trial. Subjects chewed flavorful (palatable) or less flavorful (unpalatable) gum for 5 minutes. During gum-chewing these subjects experienced positive and negative emotions, respectively. Subjects rated the taste/odor/deliciousness of each gum with a visual analog scale. Bilateral hemodynamic responses in the frontal to parietal lobes, bilateral masseter muscle activation, and heart rate were measured during gum-chewing. Data changes during gum-chewing were evaluated. Subjects’ ratings of the tastes and odors of each gum differed (p<0.001). Hemodynamic response changes were significantly elevated in the bilateral primary sensorimotor cortex during gum-chewing, in comparison to resting. The hemodynamic responses of wide brain regions showed little difference between the gum conditions; however, a difference was detected in the corresponding left frontopolar/dorsolateral prefrontal cortex. Muscle activation and heart rate were not significantly different between the gum conditions. Differential processing in the left prefrontal cortex might be responsible for emotional states caused by palatable and unpalatable foods.


1994 ◽  
Vol 77 (1) ◽  
pp. 5-10 ◽  
Author(s):  
K. K. McCully ◽  
S. Iotti ◽  
K. Kendrick ◽  
Z. Wang ◽  
J. D. Posner ◽  
...  

Simultaneous measurements of phosphocreatine (PCr) and oxyhemoglobin (HbO2) saturation were made during recovery from exercise in calf muscles of five male subjects. PCr was measured using magnetic resonance spectroscopy in a 2.0-T 78-cm-bore magnet with a 9-cm-diam surface coil. Relative HbO2 saturation was measured as the difference in absorption of 750- and 850-nm light with use of near-infrared spectroscopy. The light source and detectors were 3 cm apart. Exercise consisted of isokinetic plantar flexion in a supine position. Two 5-min submaximal protocols were performed with PCr depletion to 60% of resting values and with pH values of > 7.0. Then two 1-min protocols of rapid plantar flexion were performed to deplete PCr values to 5–20% of resting values with pH values of < 6.8. Areas of PCr peaks (every 8 s) and HbO2 saturation (every 1 s) were fit to a monoexponential function, and a time constant was calculated. The PCr time constant was larger after maximal exercise (68.3 +/- 10.5 s) than after submaximal exercise (36.0 +/- 6.5 s), which is consistent with the effects of low pH on PCr recovery. HbO2 resaturation approximated submaximal PCr recovery and was not different between maximal (29.4 +/- 5.5 s) and submaximal (27.6 +/- 6.0 s) exercise. We conclude that magnetic resonance spectroscopy measurements of PCr recovery and near-infrared spectroscopy measurements of recovery of HbO2 saturation provide similar information as long as muscle pH remains near 7.0.


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