Localized thermal changes evoked in the brain by visual and auditory stimulation

McElligott, James G.; Melzack, Ronald

doi:10.1016/0014-4886(67)90108-2

Cited by 95 publications

(66 citation statements)

References 8 publications

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“…Some in vivo information on temperature regulation during functional brain activation is available from animal studies. Localized temperature variations under visual, auditory, and somatic stimulation that were variable in duration, sign, magnitude, and form and ranged from 0.01°C to 0.2°C were observed in cat brain (7)(8)(9). Local decreases in brain temperature on the order of 0.2°C were observed in awake monkeys after short amygdala stimulation (10).…”

mentioning

confidence: 99%

Coupling between changes in human brain temperature and oxidative metabolism during prolonged visual stimulation

Yablonskiy

Ackerman

Raichle

2000

Proc. Natl. Acad. Sci. U.S.A.

209

208

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CorrectionsNEUROBIOLOGY. For the article ''Coupling between changes in human brain temperature and oxidative metabolism during prolonged visual stimulation'' by Dmitriy A. Yablonskiy, Joseph J. H. Ackerman, and Marcus E. Raichle, which appeared in number 13, June 20, 2000, of Proc. Natl. Acad. Sci. USA (97, 7603-7608), the authors note a correction in the second to last paragraph on page 7604. The sentence ''It is well known from positron-emission tomography (PET) data (17, 18) that rCMRO 2 maps in the normal human brain are largely flat despite considerable regional differences in rCBF and rCMRO 2 maps'' should read: ''It is well known from positron-emission tomography (PET) data (17,18) A fundamental discovery of modern human brain imaging with positron-emission tomography that the blood flow to activated regions of the normal human brain increases substantially more than the oxygen consumption has led to a broad discussion in the literature concerning possible mechanisms responsible for this phenomenon. Presently no consensus exists. It is well known that oxygen delivery is not the only function of systemic circulation. Additional roles include delivery of nutrients and other required substances to the tissue, waste removal, and temperature regulation. Among these other functions, the role of regional cerebral blood flow in local brain temperature regulation has received scant attention. Here we present a theoretical analysis supported by empirical data obtained with functional magnetic resonance suggesting that increase in regional cerebral blood flow during functional stimulation can cause local changes in the brain temperature and subsequent local changes in the oxygen metabolism. On average, temperature decreases by 0.2°C, but individual variations up to ؎1°C were also observed. Major factors contributing to temperature regulation during functional stimulation are changes in the oxygen consumption, changes in the temperature of incoming arterial blood, and extensive heat exchange between activated and surrounding brain tissue.

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confidence: 99%

Coupling between changes in human brain temperature and oxidative metabolism during prolonged visual stimulation

Yablonskiy

Ackerman

Raichle

2000

Proc. Natl. Acad. Sci. U.S.A.

209

208

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“…It has been stated that, in the cat, flashing lights result in locally circumscribed increases of brain temperature in the corpus geniculatum laterale (SEROTA and GERARD, 1938;MCELLIGOTT and MELZACK, 1967). Specific responses of that kind cannot be excluded for the chicken, but they seem unlikely in view of the simultaneous temperature changes throughout the brain (Fig.…”

Section: Discussionmentioning

confidence: 99%

Circadian Rhythms of Brain Temperature in the Chicken, Measured at Different Levels of Constant Illumination

Aschoff

Paul

1973

Jpn.J.Physiol

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Summary 1) Temperature was recorded continuously at various depths in the brain tissue of unanesthetized but moderately restrained chickens. The chickens were kept in a small round arena within a soundproof chamber and exposed to constant illumination for up to 18 days. Activity on a spring-suspended floor in the arena was recorded on print-out counters. Light intensity was varied from 0.05 to 100 lux, but was kept constant for at least 24 hr and in most experiments for several days.2) The brain temperature and most of the activity of all chickens showed clear circadian rhythms. For each condition, the following parameters were computed : mean level of brain temperature, range of circadian oscillation, and amount of activity. 3) Level of brain temperature and amount of activity were positively correlated with light intensity. For the range of brain temperature oscillation, such a correlation was indicated by one statistical test, but the correlation was not significant with increased intensity in two other tests. 4) Range of oscillation seemed to be positively correlated with brain temperature levels at lower values, and negatively correlated at higher values of mean level. 5) The changes in brain temperature in response to changes in light intensity were rather abrupt and simultaneous in all parts of the tissue.In most of the species studied so far, the period of the free-running circadian rhythm depends systematically on light intensity (HOFFMANN, 1965). Little is known about other rhythm parameters' such as range (= difference between maximum and minimum within one period) and mean level (= arithmetic average of all instantaneous values measured within one period). From activity records, the ratio between activity time and rest time, as well as the amount of activity per period, have been computed as subsidiary quantities (ASCHOFF and WEVER, 1962).

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“…Indeed, although, numerous experimental studies have demonstrated changes in the brain temperature of humans and animals upon functionally induced changes in brain activity, the magnitude and even sign of reported temperature changes vary substantially. For example, localized temperature variations from 0.01°C to 0.2°C were observed in animal brains (5)(6)(7)(8)(9)(10)(11)(12)(13) under different stimuli (visual, auditory, somatic). As reported in ref.…”

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confidence: 99%

“…As reported in ref. 6, the sign of temperature response to visual stimulation in cats depends on the frequency of flashing light; for low frequencies (2-12 Hz), the temperature increases, whereas at high-frequencies (42-62 Hz) the temperature decreased. Negative temperature changes, on average Ϫ0.2°C, were observed in the deep regions of the visual cortex in conscious intact human subjects by a magnetic resonance method (14), whereas positive temperature changes up to 0.15°C were observed during visual stimulation on the human head surface by infrared temperature measurements (12).…”

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confidence: 99%

Theoretical model of temperature regulation in the brain during changes in functional activity

Sukstanskiı̆

Yablonskiy

2006

Proc. Natl. Acad. Sci. U.S.A.

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The balance between metabolic heat production, heat removal by blood flow, and heat conductance defines local temperature distribution in a living tissue. Disproportional local increases in blood flow as compared with oxygen consumption during functional brain activity disturb this balance, leading to temperature changes. In this article we have developed a theoretical framework that allows analysis of temperature changes during arbitrary functional brain activity. We established theoretical boundaries on temperature changes and explained how these boundaries depend on physiology (blood flow and metabolism) and external (heat exchange with the environment) experimental conditions. We show that, in regions located deep in the brain, task performance should be accompanied by temperature decreases in regions where blood flow increases (activated regions) and by temperature increases in regions where blood flow decreases (deactivated regions). The sign of temperature effect may be reversed for superficial cortex regions, where the baseline brain temperature is lower than the temperature of incoming arterial blood due to the heat exchange with the environment. Importantly, due to heat conductance, the temperature effect is not localized to the activated region but extends to a surrounding tissue at rest over the distances regulated by the temperature-shielding effect of blood flow. This temperature-shielding effect quantifies the means by which cerebral blood flow prevents ''temperature perturbations'' from propagating away from the perturbed regions. For small activated regions, this effect also substantially suppresses the magnitude of the temperature response, making it especially important for small animal brains.brain temperature ͉ cerebral blood flow ͉ cerebral metabolism ͉ functional brain activity B asic mechanisms underlying global temperature regulation in humans and animals have attracted substantial attention from scientists, and considerable progress has been achieved in this area both in health and disease (see, e.g., refs. 1-4). However, information on brain temperature regulation, especially its relationship to function, is conflicting. Indeed, although, numerous experimental studies have demonstrated changes in the brain temperature of humans and animals upon functionally induced changes in brain activity, the magnitude and even sign of reported temperature changes vary substantially. For example, localized temperature variations from 0.01°C to 0.2°C were observed in animal brains (5-13) under different stimuli (visual, auditory, somatic). As reported in ref. 6, the sign of temperature response to visual stimulation in cats depends on the frequency of flashing light; for low frequencies (2-12 Hz), the temperature increases, whereas at high-frequencies (42-62 Hz) the temperature decreased. Negative temperature changes, on average Ϫ0.2°C, were observed in the deep regions of the visual cortex in conscious intact human subjects by a magnetic resonance method (14), whereas positive temperature changes up...

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Localized thermal changes evoked in the brain by visual and auditory stimulation

Cited by 95 publications

References 8 publications

Coupling between changes in human brain temperature and oxidative metabolism during prolonged visual stimulation

Coupling between changes in human brain temperature and oxidative metabolism during prolonged visual stimulation

Circadian Rhythms of Brain Temperature in the Chicken, Measured at Different Levels of Constant Illumination

Theoretical model of temperature regulation in the brain during changes in functional activity

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