Diapason Neurotransmitter - Serotonin

5-Hydroxytryptamine (5-HT) - The Neurotransmitter of Happiness

Application in Vibrational Sound Therapy

🔬 MOLECULAR IDENTITY

Chemical Formula

C₁₀H₁₂N₂O - 5-Hydroxytryptamine (5-HT / Serotonin)

Nomenclature

• IUPAC Name : 3-(2-aminoethyl)-1H-indol-5-ol
• Other names Serotonin, 5-HT, the happiness hormone, mood neurotransmitter
• Code 5-HT (5-Hydroxytryptamine)

Fundamental Physico-Chemical Properties

• Molecular formula : C₁₀H₁₂N₂O
• Molecular mass : 176.215 g/mol
• Structure Monoamine, tryptophan derivative, indole ring
• Appearance White to off-white crystalline powder
• Melting point : 167-168°C (salt hydrochloride)
• Solubility Water-soluble (in the form of salts)
• pKa : 10.4 (amine group), 9.8 (hydroxyl group)
• Stability Sensitive to oxidation and light

Biosynthesis

Metabolic pathway :

 Tryptophane → 5-HTP → SÉROTONINE → Mélatonine (la nuit) 

Enzymes :

1. Tryptophan hydroxylase (TPH) : Tryptophan → 5-hydroxytryptophan (5-HTP)
   • Limiting enzyme (controls synthesis)
   • TPH1 (periphery, intestine)
   • TPH2 (brain, serotonergic neurons)
2. L-aromatic amino acid decarboxylase (AADC) 5-HTP → Serotonin (5-HT)

Necessary cofactors :

• Vitamin B6 (pyridoxal phosphate): Cofactor of decarboxylase
• Iron : Cofactor of tryptophan hydroxylase
• Magnesium Enzyme activation

Historical Context

Discovery :

• 1935 Vittorio Erspamer unknowingly isolated "enteramine" from the intestinal mucosa (serotonin).
• 1948 Maurice Rapport, Arda Green and Irvine Page isolated "serotonin" from blood serum (hence the name: serum + tonic)
• 1952 Identification of enteramin and serotonin as identical molecules
• 1950s-60s : Established role of neurotransmitter
• 1987 : First SSRI (Prozac®, fluoxetine) marketed

Etymology "Serotonin" = serum + tonic (increases vascular tone)

📋 USAGE PROTOCOLS

Protocol 1: Morning Mood Boost

Objective Serotonergic activation for the day

Frequency 65.66 Hz

Morning session (7am-9am) :

1. Phase 1 - Raphe nuclei (3 min)
   • Base of the skull (brainstem)
   • Brain source of serotonin
2. Phase 2 - Prefrontal Cortex (2 min)
   • Front (mood, motivation)
   • Emotional regulation
3. Phase 3 - Limbic System (2 min)
   • Temples (amygdala, hippocampus)
   • Emotions, memory
4. Phase 4 - Gut (90% serotonin!) (3 min)
   • Abdomen (solar plexus, small intestine, colon)
   • Gut-brain axis
5. Phase 5 - Heart (2 min)
   • Sternum (emotional opening)
   • Joy, love

Total duration : 12 minutes Moment Upon waking, BEFORE breakfast Complement : 20 min exposure to natural light + protein-rich breakfast (tryptophan)

Protocol 2: Seasonal Depression (SAD - Seasonal Affective Disorder)

Objective Compensating for winter serotonin deficit

Frequency : 65.66 Hz + 71.66 Hz (Speed ​​D3)

Synergistic sequence :

1. Vitamin D3 (71.66 Hz) - 4 min
   • "Inner Sun"
   • Thymus, solar plexus
   • General vitality
2. Serotonin (65.66 Hz) - 5 min
   • Raphe nuclei, cortex, intestine
   • Mood, well-being
3. Alternation/Breathing (3 min)
   • 71.66 Hz ↔ 65.66 Hz
   • Difference: 6 Hz (theta/alpha waves)
   • Solar plexus

Total duration : 12 minutes Period November to March, daily upon waking Complement Light therapy: 10,000 lux, 30 minutes/day

Protocol 3: Binge Eating & Bulimia

Objective Appetite regulation, satiety signal

Frequency 65.66 Hz

Application :

15 minutes BEFORE meals :

• Abdomen (stomach, intestines) - 5 min
• Raphe nuclei (base of skull) - 2 min
• Prefrontal cortex (impulse control) - 2 min

Duration 9 minutes before each main meal Frequency 3 times a day for 30 days Complement Diet rich in tryptophan, B6, magnesium

Protocol 4: Gut-Brain Axis (Digestive Disorders & Mood)

Objective : Bidirectional harmonization gut ↔ brain

🔬 SEROTONIN: A MULTIFACETED PHYSIOLOGY

Distribution: 90% Intestinal!

Body distribution (little-known fact):

• Intestines : 90-95% (enterochromaffin cells of the mucosa)
• Blood platelets : 5-8% (storage, transport)
• Brain (CNS) : 1-2% (raphe nuclei)

BUT Despite only making up 1-2% of the brain, cerebral serotonin has major effects on mood, behavior, and cognition!

Blood-brain barrier :

• Peripheral serotonin DO NOT CROSS the BBE
• Cerebral serotonin = synthesized locally in the brain
• Intestinal and cerebral serotonin = two separate pools

Synthesis and Degradation

Synthesis :

 Tryptophane (alimentaire) → [TPH + Fe] → 5-HTP → [AADC + B6] → SÉROTONINE 

Degradation :

 Sérotonine → [MAO-A] → 5-HIAA (acide 5-hydroxyindoleacétique) → Urine 

Regulation :

• Availability in tryptophan (food grade)
• Cofactors (B6, iron, magnesium)
• Enzyme activity (TPH)
• Stress, inflammation (↓ serotonin)

Serotonergic Neurotransmission

Serotonergic neurons :

• Location : Raphe nuclei (brainstem)
• Diffuse projections throughout the brain
• They modulate the activity of many regions

Receptors :

• 14 subtypes of 5-HT receptors (5-HT₁ to 5-HT₇, with subtypes A, B, C, D...)
• Located on neurons, glial cells, blood vessels
• Effects vary depending on the receptor

Main receptors :

• 5-HT₁A Mood, anxiety (key receptor for antidepressants)
• 5-HT₂A : Perception, hallucinations (LSD, psilocybin)
• 5-HT₂C Appetite, eating behavior
• 5-HT₃ Nausea, vomiting (antiemetics)
• 5-HT₄ Intestinal motility
• 5-HT₇ Circadian rhythm, thermoregulation

Recapture :

• SERT Carrier (5-HTT, SLC6A4)
• 5-HT reuptake in presynaptic neuron
• Target of SSRI antidepressants (inhibit SERT → ↑ synaptic 5-HT)

Biological Functions

1. Mood Regulation

Central role :

• emotional well-being
• Optimism, serenity
• Prevention of depression
• Stress management

"Serotonergic hypothesis of depression" :

• Serotonin deficiency → Depression
• Base of SSRI antidepressants (Prozac, Zoloft, Seroplex...)
• Current debate Hypothesis called into question (depression = multifactorial), but SSRIs are clinically effective

Effects :

• ↑ Positive mood
• ↓ Anxiety, rumination
• ↑ Emotional resilience
• ↑ Motivation, mental energy

2. Sleep and Circadian Rhythm

Precursor to melatonin :

 Sérotonine (JOUR) → [AANAT + HIOMT, NUIT] → Mélatonine 

Day/night balance :

• DAY : ↑ Serotonin → Wakefulness, alertness, activity
• NIGHT : ↓ Serotonin, ↑ Melatonin → Sleep

Sleep regulation :

• Serotonin modulates REM sleep (dreams)
• Influence of sleep architecture
• Raphe nuclei involved in wakefulness/sleep

3. Appetite and Satiety

Satiety signal :

• 5-HT₂C Activation → ↓ Appetite
• Regulation of food intake
• Food impulse control

Serotonin deficiency → Food cravings, especially towards:

• Fast-acting sugars (carbohydrates)
• Chocolate
• "Comfort" foods

Self-medication Carbohydrates increase brain tryptophan, which in turn increases serotonin (temporary effect).

Applications :

• Eating disorders (ED)
• Bulimia (effective SSRIs)
• Obesity (complex link)

4. Digestive Functions (90% of Serotonin!)

Intestinal motility :

• Regulation of peristalsis
• Propulsion of the food bolus
• Smooth muscle contraction/relaxation

Too much intestinal serotonin → Diarrhea (carcinoid syndrome) Too little → Constipation

Nausea and vomiting :

• 5-HT₃ activation → Vomiting center
• Chemotherapy Massive 5-HT release → Severe nausea
• Antiemetics (ondansetron): Block 5-HT₃

Gut-brain axis :

• 90% of serotonin is produced in the gut
• Influence on mood via the vagus nerve (active debate)
• Microbiota influence on intestinal serotonin production
• Probiotics (impact on mood, research ongoing)

5. Perception of Pain

Nociception modulation :

• Descending pain inhibitory pathways
• Spinal serotonin ↓ pain transmission
• Fibromyalgia: Suspected serotonin deficiency

SSRIs and chronic pain :

• Modest analgesic effect
• Duloxetine (SNRI) approved for fibromyalgia

6. Cognitive Functions

Memory and learning :

• Hippocampal modulation
• Neuroplasticity
• Memory consolidation

Attention and concentration :

• Vigilance
• Cognitive flexibility

Deficit → "Mental fog", difficulty concentrating

7. Social Behavior

Aggressiveness :

• ↓ Serotonin → ↑ Impulsivity, aggressiveness
• Pulse control
• Appropriate social behavior

Studies :

• Primates: ↓ 5-HT → Antisocial behavior
• Humans: Weak correlation between 5-HT and violence, but real

8. Libido and Sexual Function

Complex effects :

• 5-HT₂ activation → ↓ Libido, ↓ orgasm
• A common side effect of SSRIs Sexual dysfunction (30-70% of patients)

9. Cardiovascular Regulation

Platelet serotonin :

• Stored in blister packs (5-8% of the total)
• Released during coagulation
• Vasoconstriction (5-HT₂A on vascular smooth muscle)
• Platelet aggregation (promotes blood clotting)

Carcinoid syndrome 5-HT-secreting tumor → Flushing, diarrhea, valvular heart disease

10. Other Functions

Thermoregulation :

• Body temperature regulation

Sexual reproductive function :

• Ovulation (hormonal influences)

Bone density :

• Intestinal serotonin inhibits bone formation (negative effect)
• SSRIs: Slightly increased risk of fractures (controversial)

Serotonergic Deficiency

Causes

1. Tryptophan deficiency :

• Low-protein diet
• Unbalanced vegan diet (tryptophan = essential amino acid)
• Competition with other amino acids (BCAAs)

2. Cofactor Deficit :

• Vitamin B6 Essential for decarboxylase
• Iron : Tryptophan hydroxylase cofactor
• Magnesium Enzyme activation

3. Chronic stress :

• HPA axis activation (cortisol)
• Inflammation (pro-inflammatory cytokines)
• ↓ Available tryptophan (activated kynurenine pathway)
• Depletion of reserves

4. Chronic inflammation :

• Cytokines (TNF-α, IL-6) activate IDO (indoleamine 2,3-dioxygenase)
• IDO degrades tryptophan → kynurenine (instead of serotonin)
• Inflammatory depression

5. Lack of sunlight :

• Light stimulates serotonin synthesis
• Seasonal affective disorder (SAD): ↓ Serotonin in winter

6. Intestinal dysbiosis :

• Imbalanced gut microbiota → ↓ Intestinal serotonin production
• Intestinal inflammation → Impact on the nervous system (?)

7. Genetics :

• SERT (5-HTTLPR) transporter gene polymorphisms
• "Short" variant: ↓ SERT expression, vulnerability to depression/anxiety

Symptoms

Psychiatric manifestations :

• Depression Sadness, anhedonia (loss of pleasure)
• Anxiety Excessive worry, panic attacks
• Irritability , nervousness
• Obsessive-compulsive disorder (TOC)
• Impulsivity , aggressiveness

Sleep disorders :

• Insomnia
• Non-restorative sleep
• Nightmares

Eating disorders :

• Sugar cravings
• Bulimia
• Hyperphagia

Physical symptoms :

• Chronic fatigue
• Widespread pain (fibromyalgia?)
• Migraines
• Digestive problems (constipation, irritable bowel syndrome)

Cognitive impairment :

• Difficulty concentrating
• Memory problems
• "Mental fog"

Decreased libido

Diagnosis

No reliable blood test :

• Blood serotonin ≠ brain serotonin (does not cross the blood-brain barrier)
• Urinary 5-HIAA (metabolite) level: Not very informative except in carcinoid tumors

Clinical diagnosis Symptoms + context

Natural Serotonin Increase

Food

Foods rich in tryptophan :

Strategy :

• Quality protein at every meal
• Complex carbohydrates (facilitate tryptophan passage into the blood-brain barrier)
• Timing: Protein-rich breakfast (serotonin for the day)

5-HTP Precursor :

• Supplement (50-300 mg/day)
• It crosses the blood-brain barrier (unlike serotonin).
• Efficacy for mild to moderate depression (limited studies)
• Precaution Not with SSRIs (risk of serotonin syndrome)

Sunlight

Natural light exposure :

• Stimulates brain serotonin synthesis
• Mechanism: Light → retina → brain → raphe nuclei
• 20-30 min/day minimum
• Especially in the morning (circadian synchronization)

Light therapy (10,000 lux):

• Effective seasonal depression
• 30 minutes/day in the morning

Physical Exercise

Powerful effect :

• ↑ Cerebral tryptophan
• ↑ Serotonin synthesis
• ↑ Receptor sensitivity
• Immediate release (acute effect)
• Neuroplasticity (chronic effect)

Recommendations :

• Aerobics 30-60 min, 3-5x/week
• Yoga, tai chi (↓ cortisol, ↑ serotonin)

Meditation and Mindfulness

Effects :

• ↑ Serotonin (brain imaging)
• ↓ Stress (↓ cortisol)
• Neuroplasticity (↑ grey matter)

Practical 20 minutes/day, regularity is key

Massage

Therapeutic touch :

• Increased serotonin, increased dopamine
• ↓ Cortisol
• Immediate well-being

Positive Social Interactions

Human connection :

• Pleasant conversations
• Laughter, humor
• Acts of kindness (giving)
• ↑ Oxytocin + serotonin

Quality Sleep

Virtuous circle :

• Sleep → ↑ Serotonin (next day)
• Serotonin → Melatonin → Sleep

Sleep hygiene Essential

Probiotics ("Psychobiotics")

Gut-brain axis :

• Certain strains (Lactobacillus, Bifidobacterium) influence serotonin
• The mechanism is debated (vagus nerve? metabolites?)
• Positive preliminary studies (anxiety, mild depression)

Drug Treatments

SSRIs (Selective Serotonin Reuptake Inhibitors)

Mechanism : Blocking the SERT transporter → ↑ synaptic serotonin

Molecules :

• Fluoxetine (Prozac®)
• Sertraline (Zoloft®)
• Paroxetine (Deroxat®)
• Escitalopram (Seroplex®)
• Citalopram (Seropram®)

Indications :

• Major depression
• Anxiety disorders (GAD, panic disorder, social phobia, OCD)
• Bulimia

Efficiency :

• Moderate-severe depression: Real benefit
• Mild depression: Debated (similar to placebo effect)
• Time to action: 2-4 weeks

Side effects :

• Sexual dysfunction (30-70%)
• Nausea, digestive problems (start of treatment)
• Weight gain (variable)
• Withdrawal syndrome (abrupt cessation)

SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors)

Molecules : Venlafaxine (Effexor®), Duloxetine (Cymbalta®)

Indications Depression, anxiety, chronic pain (fibromyalgia)

Others

Tricyclic : Older antidepressants (amitriptyline, clomipramine) IMAO Monoamine oxidase inhibitors (rarely used, food interactions)

🎯 FREQUENCY CHARACTERISTICS 65.66 Hz

Acoustic Properties

Frequency range Deep gravel

• Perception Marked body vibration + clear auditory perception
• Musical Octave : Quasi Do2 (65.41 Hz)
• Wavelength ~5.23 meters in the air
• Tissue penetration Excellent, it resonates with the nervous system and intestines.

Resonance "Well-being"

Theoretical targeting :

• Harmonization of serotonergic system (rapheic nuclei, intestine)
• Mood support and emotional balance
• Optimizing the gut-brain axis
• Balancing appetite/sleep/mood

Symbolism of Do :

• Root note, fundamental of the scale
• Stability, emotional anchoring
• Foundation of well-being (like vitamin C = foundation of cellular health)

🎵 THERAPEUTIC APPLICATIONS

Tuning Fork Serotonin - 65.66 Hz

Technical Specifications

• Kind Weighted tuning fork
• Precise frequency : 65.66 Hz (±0.1 Hz)
• Material Medical alloy
• Resonance duration 40-60 seconds
• Weight 120-170g
• Length : 13-15 cm

Potential Therapeutic Effects

Mood improvement :

• Moral support, optimism
• Emotional resilience
• Prevention of mild depression
• Joy of living

Anxiety reduction :

• Calming mental ruminations
• Inner calm
• Stress management
• Emotional balance

Appetite regulation :

• Controlling food cravings
• Satiety signal
• Healthy relationship with food

Sleep optimization :

• Serotonin (day) → Melatonin (night)
• Preparing for restful sleep

Digestive health :

• Balanced intestinal motility
• Harmonious gut-brain axis
• Abdominal well-being

Mental clarity :

• Concentration
• Memory
• Cognitive flexibility