RESUMEN
Pain is a complex experience that involves sensory, emotional, and motivational components. It has been suggested that pain arising from the head and orofacial regions evokes stronger emotional responses than pain from the body. Indeed, recent work in rodents reports different patterns of activation in ascending pain pathways during noxious stimulation of the skin of the face when compared to noxious stimulation of the body. Such differences may dictate different activation patterns in higher brain regions, specifically in those areas processing the affective component of pain. We aimed to use ultra-high field functional magnetic resonance imaging (fMRI at 7-Tesla) to determine whether noxious thermal stimuli applied to the surface of the face and body evoke differential activation patterns within the ascending pain pathway in awake humans (n=16). Compared to the body, noxious heat stimulation to the face evoked more widespread signal changes in prefrontal cortical regions and numerous brainstem and subcortical limbic areas. Moreover, facial pain evoked significantly different signal changes in the lateral parabrachial nucleus, substantia nigra, paraventricular hypothalamus, and paraventricular thalamus, to those evoked by body pain. These results are consistent with recent preclinical findings of differential activation in the brainstem and subcortical limbic nuclei and associated cortices during cutaneous pain of the face when compared with the body. The findings suggest one potential mechanism by which facial pain could evoke a greater emotional impact than that evoked by body pain.
Asunto(s)
Mapeo Encefálico , Sistema Límbico , Imagen por Resonancia Magnética , Núcleos Parabraquiales , Humanos , Masculino , Femenino , Adulto , Núcleos Parabraquiales/fisiología , Núcleos Parabraquiales/diagnóstico por imagen , Sistema Límbico/diagnóstico por imagen , Sistema Límbico/fisiopatología , Adulto Joven , Mapeo Encefálico/métodos , Dolor/fisiopatología , Dolor/diagnóstico por imagen , Dolor Facial/diagnóstico por imagen , Dolor Facial/fisiopatología , Vías Nerviosas/fisiopatología , Vías Nerviosas/diagnóstico por imagenRESUMEN
The midbrain periaqueductal grey (PAG) is a critical region for the mediation of pain-related behavioural responses. Neuronal tract tracing techniques in experimental animal studies have demonstrated that the lateral column of the PAG (lPAG) displays a crude somatotopy, which is thought to be critical for the selection of contextually appropriate behavioural responses, without the need for higher brain input. In addition to the different behavioural responses to cutaneous and muscle pain - active withdrawal versus passive coping - there is evidence that cutaneous pain is processed in the region of the lPAG and muscle pain in the adjacent ventrolateral PAG (vlPAG). Given the fundamental nature of these behavioural responses to cutaneous and muscle pain, these PAG circuits are assumed to have been preserved, though yet to be definitively documented in humans. Using ultra-high field (7-Tesla) functional magnetic resonance imaging we determined the locations of signal intensity changes in the PAG during noxious cutaneous heat stimuli and muscle pain in healthy control participants. Images were processed and blood oxygen level dependant (BOLD) signal changes within the PAG determined. It was observed that noxious cutaneous stimulation of the lip, cheek, and ear evoked maximal increases in BOLD activation in the rostral contralateral PAG, whereas noxious cutaneous stimulation of the thumb and toe evoked increases in the caudal contralateral PAG. Analysis of individual participants demonstrated that these activations were located in the lPAG. Furthermore, we found that deep muscular pain evoked the greatest increases in signal intensity in the vlPAG. These data suggest that the crude somatotopic organization of the PAG may be phyletically preserved between experimental animals and humans, with a body-face delineation capable of producing an appropriate behavioural response based on the location and tissue origin of a noxious stimulus.
Asunto(s)
Mialgia , Sustancia Gris Periacueductal , Animales , Humanos , Sustancia Gris Periacueductal/fisiología , Neuronas , Conducta Animal/fisiología , Imagen por Resonancia MagnéticaRESUMEN
BACKGROUND: Texture is a major quality parameter for the acceptability of canned whole beans. Prior knowledge of this quality trait before processing would be useful to guide variety development by bean breeders and optimize handling protocols by processors. The objective of this study was to evaluate and compare the predictive power of visible and near infrared reflectance spectroscopy (visible/NIRS, 400-2498 nm) and hyperspectral imaging (HYPERS, 400-1000 nm) techniques for predicting texture of canned black beans from intact dry seeds. Black beans were grown in Michigan (USA) over three field seasons. The samples exhibited phenotypic variability for canned bean texture due to genetic variability and processing practice. Spectral preprocessing methods (i.e. smoothing, first and second derivatives, continuous wavelet transform, and two-band ratios), coupled with a feature selection method, were tested for optimizing the prediction accuracy in both techniques based on partial least squares regression (PLSR) models. RESULTS: Visible/NIRS and HYPERS were effective in predicting texture of canned beans using intact dry seeds, as indicated by their correlation coefficients for prediction (Rpred ) and standard errors of prediction (SEP). Visible/NIRS was superior (Rpred = 0.546-0.923, SEP = 7.5-1.9 kg 100 g-1 ) to HYPERS (Rpred = 0.401-0.883, SEP = 7.6-2.4 kg 100 g-1 ), which is likely due to the wider wavelength range collected in visible/NIRS. However, a significant improvement was reached in both techniques when the two-band ratios preprocessing method was applied to the data, reducing SEP by at least 10.4% and 16.2% for visible/NIRS and HYPERS, respectively. Moreover, results from using the combination of the three-season data sets based on the two-band ratios showed that visible/NIRS (Rpred = 0.886, SEP = 4.0 kg 100 g-1 ) and HYPERS (Rpred = 0.844, SEP = 4.6 kg 100 g-1 ) models were consistently successful in predicting texture over a wide range of measurements. CONCLUSION: Visible/NIRS and HYPERS have great potential for predicting the texture of canned beans; the robustness of the models is impacted by genotypic diversity, planting year and phenotypic variability for canned bean texture used for model building, and hence, robust models can be built based on data sets with high phenotypic diversity in textural properties, and periodically maintained and updated with new data. © 2017 Society of Chemical Industry.
Asunto(s)
Alimentos en Conserva/análisis , Phaseolus/química , Espectroscopía Infrarroja Corta/métodos , Análisis de los Mínimos Cuadrados , Control de Calidad , Semillas/químicaRESUMEN
KEY MESSAGE: Fivefold diversity for cooking time found in a panel of 206 Phaseolus vulgaris accessions. Fastest accession cooks nearly 20 min faster than average. SNPs associated with cooking time on Pv02, 03, and 06. Dry beans (Phaseolus vulgaris L.) are a nutrient dense food and a dietary staple in parts of Africa and Latin America. One of the major factors that limits greater utilization of beans is their long cooking times compared to other foods. Cooking time is an important trait with implications for gender equity, nutritional value of diets, and energy utilization. Very little is known about the genetic diversity and genomic regions involved in determining cooking time. The objective of this research was to assess cooking time on a panel of 206 P. vulgaris accessions, use genome- wide association analysis (GWAS) to identify genomic regions influencing this trait, and to test the ability to predict cooking time by raw seed characteristics. In this study 5.5-fold variation for cooking time was found and five bean accessions were identified which cook in less than 27 min across 2 years, where the average cooking time was 37 min. One accession, ADP0367 cooked nearly 20 min faster than average. Four of these five accessions showed close phylogenetic relationship based on a NJ tree developed with ~5000 SNP markers, suggesting a potentially similar underlying genetic mechanism. GWAS revealed regions on chromosomes Pv02, Pv03, and Pv06 associated with cooking time. Vis/NIR scanning of raw seed explained 68 % of the phenotypic variation for cooking time, suggesting with additional experimentation, it may be possible to use this spectroscopy method to non-destructively identify fast cooking lines as part of a breeding program.