From: hubermanlab
The intricate communication between the brain and the body ensures appropriate responses to a multitude of internal and external stimuli. Two such responses, fever and nausea, serve as prime examples of how brain chemistry influences bodily states to protect and heal the body.
Fever: The Brain’s Thermal Response
Fever is an increase in body temperature often triggered by the presence of pathogens or foreign substances in the body. Essentially, it represents an adaptive response wherein the body attempts to “cook” the invaders or the cause of dysfunction. This physiological state is orchestrated by the brain, which detects harmful agents and subsequently adjusts the body’s temperature.
Mechanism of Fever Induction
Neurons within the circumventricular organs, particularly those called the OVLT (Organum Vasculosum of the Lamina Terminalis), detect pathogens or foreign entities in the bloodstream. Upon activation, these neurons release inflammatory cytokines, signaling for an increase in body temperature [01:32:28].
Role of the Preoptic Area
The preoptic area of the hypothalamus receives signals from the OVLT neurons, which results in an uptick in body temperature. At the core, the brain is highly protective of its neurons, which do not readily regenerate. Thus, the fever response is part of the body’s internal defense mechanism against infection.
Safe Management of Fever
Fever management is crucial, especially when temperatures approach dangerous levels (above 102-104°F). Cooling measures should focus on the palms, soles, and upper face to lower the body’s core temperature effectively. Effective fever management can aid in the body’s recovery processes [01:37:05].
Nausea: The Protective Emetic Response
Nausea often serves as a precursor to vomiting, a reflex triggered to expel harmful substances from the body. This sensation and the subsequent act of vomiting are regulated by specific regions in the brain.
The Area Postrema and CTZ
The area postrema and chemoreceptor trigger zone (CTZ) are crucial to understanding nausea. These brainstem regions lack a blood-brain barrier and directly sample the chemical composition of the blood. When toxins or certain chemicals are detected, these neurons initiate the vomit reflex to protect the body from ingested poisons or other harmful substances.
Cognitive Influence on Nausea
Interestingly, nausea can also be induced by cognitive factors such as memories or observation of others vomiting. The brain’s interpretative processes can intensify or trigger nausea based on past experiences or learned associations [01:23:37].
Remedies for Nausea
Several natural and medicinal remedies can alleviate nausea. Ginger, in particular, is supported by research to significantly reduce nausea symptoms due to its action on the brain’s nausea centers.
Summary
Fever and nausea are two critical responses controlled by the brain’s interpretation of internal and external stimuli. These responses exemplify the brain’s role in maintaining bodily homeostasis and defending against threats. Understanding the mechanisms behind these responses can guide strategies for managing them effectively, ensuring both immediate relief and long-term health.