Multiple intermittent administration of psychostimulants induces a behavioral sensitization, which is characterized by the augmentation of locomotor activity and stereotyped behavior, even after their long-term withdr...Multiple intermittent administration of psychostimulants induces a behavioral sensitization, which is characterized by the augmentation of locomotor activity and stereotyped behavior, even after their long-term withdrawal. This kind of behavioral effects is thought to serve as a useful animal model that mimics the behavioral responses in drug craving.展开更多
Many receptors,including thermal receptors and mechanical receptors,are only activated by stimuli within a clearly defined range of intensities.Differences in the receptive ranges enable individual receptors and their...Many receptors,including thermal receptors and mechanical receptors,are only activated by stimuli within a clearly defined range of intensities.Differences in the receptive ranges enable individual receptors and their sensory centers to precisely detect the intensity of the stimulus and changes in intensity.Baroreceptors are the sensory terminals of the baroreflex.It is well understood that an increasing number of baroreceptors are recruited to produce afferent action potentials as the blood pressure increases,indicating that individual baroreceptors have different pressure thresholds.The present study revealed that individual baroreceptors could stop their afferent signals when the blood pressure exceeds a certain level,indicating that individual baroreceptors are sensitive to a specific range of blood pressure.The receptive ranges of individual baroreceptors differ in terms of the total range,the lower threshold,and the upper threshold.Of 85 baroreceptors examined in this study,the upper thresholds for about half were within the physiological blood pressure range.These results indicate that supraphysiological blood pressure is unlikely to be encoded by the recruitment of more baroreceptors.Instead,supraphysiological blood pressure levels might be signaled by an increase in the frequency of action potentials or by other mechanisms.In conclusion,our results indicate that rabbit baroreceptors are activated by blood pressure levels within specific receptive ranges.These findings should encourage further studies to examine the role of population coding of blood pressure by baroreceptors in the baroreflex.展开更多
文摘Multiple intermittent administration of psychostimulants induces a behavioral sensitization, which is characterized by the augmentation of locomotor activity and stereotyped behavior, even after their long-term withdrawal. This kind of behavioral effects is thought to serve as a useful animal model that mimics the behavioral responses in drug craving.
基金supported by the National Natural Science Foundation of China(30770701)the Fundamental Research Funds for the Central Universities(GK201302052,GK261001007)
文摘Many receptors,including thermal receptors and mechanical receptors,are only activated by stimuli within a clearly defined range of intensities.Differences in the receptive ranges enable individual receptors and their sensory centers to precisely detect the intensity of the stimulus and changes in intensity.Baroreceptors are the sensory terminals of the baroreflex.It is well understood that an increasing number of baroreceptors are recruited to produce afferent action potentials as the blood pressure increases,indicating that individual baroreceptors have different pressure thresholds.The present study revealed that individual baroreceptors could stop their afferent signals when the blood pressure exceeds a certain level,indicating that individual baroreceptors are sensitive to a specific range of blood pressure.The receptive ranges of individual baroreceptors differ in terms of the total range,the lower threshold,and the upper threshold.Of 85 baroreceptors examined in this study,the upper thresholds for about half were within the physiological blood pressure range.These results indicate that supraphysiological blood pressure is unlikely to be encoded by the recruitment of more baroreceptors.Instead,supraphysiological blood pressure levels might be signaled by an increase in the frequency of action potentials or by other mechanisms.In conclusion,our results indicate that rabbit baroreceptors are activated by blood pressure levels within specific receptive ranges.These findings should encourage further studies to examine the role of population coding of blood pressure by baroreceptors in the baroreflex.
