Q and A: about health and research

Thyroid hormones are chemical messengers produced by the thyroid gland that circulate through the bloodstream and influence cells throughout the body. Their primary role is the regulation of metabolism, but thyroid hormones also affect brain function, mood, cognition, and behavior. The Brain–Pituitary–Thyroid Axis Thyroid function is regulated through a three-step hormonal system known as the hypothalamic-pituitary-thyroid (HPT) axis. The hypothalamus, located in the brain, releases thyrotropin-releasing hormone (TRH). TRH stimulates the pituitary gland to release thyroid-stimulating hormone (TSH). TSH then stimulates the thyroid gland in the neck to produce thyroid hormones, primarily T4 (thyroxine). T4 is subsequently converted into the more biologically active hormone T3 (triiodothyronine). This regulatory system allows the brain to influence how much thyroid hormone circulates throughout the body. Thyroid Hormones and Metabolism One of the major functions of thyroid hormones is to ...

Research into the neurobiology of stress has transformed the understanding and treatment of Post-Traumatic Stress Disorder (PTSD). Studies in animals revealed that intense and prolonged stress does not simply affect emotions psychologically—it physically remodels the brain itself. These discoveries have led directly to new treatments that help restore emotional regulation and cognitive control in people suffering from trauma-related disorders. The Brain Under Stress When a person experiences danger or trauma, the brain rapidly releases stress chemicals known as catecholamines, particularly norepinephrine. In short bursts, this response is protective and necessary for survival. However, during chronic stress or repeated trauma, these neurochemical systems become overactivated. High levels of norepinephrine weaken the functioning of the prefrontal cortex (PFC), the region responsible for rational thinking, impulse control, concentration, and emotional regulation. At the same time, stress...

Update: Postural Orthostatic Tachycardia Syndrome (POTS) Postural Orthostatic Tachycardia Syndrome (POTS) is a disorder of the autonomic nervous system, which regulates involuntary functions such as heart rate, blood pressure, circulation, and digestion. It is characterized by orthostatic intolerance and an excessive increase in heart rate after moving to an upright position, often accompanied by disabling multisystem symptoms. POTS and Long COVID Long COVID is associated with persistent autonomic dysfunction, including orthostatic intolerance and POTS. In a cross-sectional study of individuals with symptoms lasting at least four weeks after moderate COVID-19, beat-to-beat cardiovascular recordings and a novel geometric method were used to characterize baroreflex sensitivity (BRS). During orthostasis, patients exhibited significantly lower BRS than healthy controls. Reduced BRS was associated with higher arterial blood pressure and heart rate, as well as lower heart-rate variabilit...