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Heroin and Brain Temperature: Exploring the Physiology Behind Substance Abuse

Updated: Aug 22, 2018

By Avery St. Sauveur

Art by Mykl Ambros

While it seems unlikely that a single molecule could have a vice grip on the United States, the last several years have indicated the potency of opiate-derived drugs. The opioid crisis has come to consume the country, with over 27.1 million people reportedly using illicit drugs or misusing prescription drugs, and a startling 30,000 Americans succumbing to opioid overdoses in 2014 alone. While it is understood that this level of abuse wreaks havoc on individuals and families and incurs a variety of costs within communities, there is a fundamental lack of understanding of the mechanisms behind the drugs at hand.

Addiction and substance abuse occupy a realm within medicine often misunderstood by the public. Stereotypes of addicts perpetuate modern culture and motivate a pervasive stigma that prevents many from receiving care and full rehabilitation. Preconceived notions influence the care patients receive, the support encountered by patients seeking recovery, the size of prison populations, and even the willingness of insurance providers to cover addiction treatments.

when doses of heroin were increased, brain temperatures began to plummet.

In this way, opioid research has become increasingly important and relevant. In a recent study conducted by Bola & Kiyatkin, researchers analyzed temperature levels in the brain to better understand the physiology of opiate use. Experimenters injected rat subjects with heroin then recorded temperatures at three sites: the nucleus accumbens (NAc), the temporal muscle (located on the side of the head), and the skin. The NAc was chosen for the brain site because of its heavy involvement in sensory/motor functions and in the processing of rewarding stimuli. Monitoring these areas allowed researchers to trace the path of heat production in the brain, and to better understand how that heat is then lost via skin surfaces.

Of the manipulated variables, researchers found that the condition that brought the most profound changes in temperature was an increase in dosage. All other conditions maintained the rats at a lower, standard dose considered appropriate for their weight and considered proportionate to human consumption. Each condition saw a small but significant increase in temperature in the locations monitored. However, when doses of heroin were increased past the standard dose, brain temperatures began to plummet and a considerable amount of heat was lost via skin surfaces. This effect is commonly seen with general anesthetics, and this reduction in brain metabolic activity may be an important component to the concept of central nervous system depression, a potential effect of large doses of opioids. This can cause profound sedation and possibly even overdose and death.

Potentially the best way to reverse this stigma and move towards better solutions is to understand the “how” component to addiction and to better research the effects of opioids and other problematic drugs. Besides the immeasurable emotional effects brought about by widespread opioid abuse, addiction costs communities and the country millions in disability, increases in violence and crime, and the spread of infectious disease. In funding addiction research, there is hope to eventually reduce the burden of these costs as more effective treatment and prevention methods are established.


Bola, R. A., & Kiyatkin, E. A. (2017). brain temperature effects of intravenous heroin:

State dependency, environmental modulation, and the effects of

dose. Neuropharmacology, 126, 271-280.

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