"We found that the histamine in the brain was triggered by the inflammatory response and directly inhibited the release of serotonin, by attaching to inhibitory receptors on the serotonin neurons. These inhibitory receptors are also present on human serotonin neurons.
During acute inflammation, extracellular serotonin levels are decreased as a function of increased brain histamine.
Drugs that prevent the reuptake of serotonin include SNRIs, SSRIs, tramadol, certain tricyclic antidepressants (TCAs), certain opioids, dextromethorphan, the antihistamines chlorpheniramine and brompheniramine, and herbals such as St John's wort.
These results suggest that histamine plays an important role in neuroinflammation-related diseases, including depression, via microglia. Interestingly, mast cells, which can promote inflammation and allergic reactions via the release of histamine, are also present in the brain.
However, in the brain, histamine mainly functions as a wake-promoting and rapid eye movement (REM) sleep–suppressing neurotransmitter, with additional effects on feeding and endocrine function [4].
Histamine does not only modulate the immune response and inflammation, but also acts as a neurotransmitter in the mammalian brain. The histaminergic system plays a significant role in the maintenance of wakefulness, appetite regulation, cognition and arousal, which are severely affected in neuropsychiatric disorders.
Histamine stimulates prolactin release via the H2 receptor, which in turn inhibits dopamine production. Histamine can locally increase the concentration of norepinephrine.
While there is no solid evidence to prove the connection between histamine and mental disorders, symptoms like hyperactivity, obsessive-compulsive behavior, panic, anxiety, and depression are often observed among those who suffer from histamine imbalance.
Too much histamine frequently causes anxiety, panic attacks, and insomnia. There are many potential underlying causes for too much histamine and there is no universal treatment that works for everything. Taking activated charcoal at night, however, can be a great short-term solution for some.
In the brain, histamine acts as a neurotransmitter which can affect the levels of mood altering neurotransmitters such as GABA, dopamine and serotonin; causing the increased expression of anxious and depressive feelings.
Certain drugs and substances such as caffeine, alcohol, nicotine, NutraSweet, antidepressants, and some cholesterol-lowering medications deplete serotonin and other neurotransmitter levels. Hormone changes cause low levels of serotonin and neurotransmitter imbalances.
The drugs and supplements that could potentially cause serotonin syndrome include: Selective serotonin reuptake inhibitors (SSRIs), antidepressants such as citalopram (Celexa), fluoxetine (Prozac), fluvoxamine (Luvox), escitalopram (Lexapro), paroxetine (Paxil, Pexeva, Brisdelle) and sertraline (Zoloft)
age-related health and brain changes. chronic stress. a lack of exposure to natural light. lack of physical activity.
Histamine intolerance occurs when you have a high level of histamine in your body. It can happen if your body can't break down histamine properly. It causes a variety of symptoms, including: Headaches or migraines.
Basophil releases heparin, histamine and serotonin.
Studies have found that allergic reactions release compounds in the body called cytokines, which play a role in inflammation and may reduce levels of the hormone serotonin, which helps maintain feelings of well-being.
Hydroxyzine is used to help control anxiety and tension caused by nervous and emotional conditions. It can also be used to help control anxiety and produce sleep before surgery.
When you're all stressed out, your body releases hormones and other chemicals, including histamine, the powerful chemical that leads to allergy symptoms. While stress doesn't actually cause allergies, it can make an allergic reaction worse by increasing the histamine in your bloodstream.
Hydroxyzine is an antihistamine. It is approved for the treatment of anxiety. However, hydroxyzine is also used to treat difficulty sleeping, nausea, vomiting, itching, skin rash, and allergies.
Excess histamine can cause joint pain, musculoskeletal or connective tissue pain (fibromyalgia), chronic fatigue, bloating, constipation or diarrhea, estrogen dominance and painful menstruation, hypotension, tachycardia or rapid heart rate, dizziness, trouble regulating your body temperature, and trouble sleeping.
Doxepin hydrochloride and amitriptyline hydrochloride may be the most potent antihistamines known, and the antihistaminic potencies of these and the other tricyclic antidepressant drugs may relate directly to their ability to cause sedation and drowsiness in patients.
Histamine constricts airway smooth muscle by a direct effect on the muscle and indirectly by stimulating a reflex that releases acetylcholine from the vagus nerves (8, 19, 24).
Monoamine oxidase inhibitors (MAOIs): This medication blocks the activity of an enzyme that breaks down serotonin, norepinephrine, and dopamine.
Aside from producing the desired histamine reducing effects, many antihistamines can also elicit psychomotor activation and reward, both of which are associated with increased dopamine concentrations in the nucleus accumbens (NAc).