In-Depth Notes on Love and Attraction and Chemical Interactions

Chemical Basis of Love and Attraction

• Chemical Machines: Humans and all organisms function as complex biochemical systems driven by chemical signals.

Emotions and Relationships

• Chemistry of Emotions: Emotions are products of chemical interactions within the body.
• Components of Relationships:
  • Attraction
  • Romantic love
  • Attachment
  • Love
  • Pleasure
  • Sex
  • Addiction

Pheromones and Attraction

• Definition: Pheromones are chemical substances secreted by organisms that trigger specific unlearned responses in other members of the same species.
• Example in Nature: Female silkworm moth secretes bombykol to attract males.
  • Male moths possess specialized antennae to detect this pheromone.

Mechanism of Pheromonal Communication

• Pheromones function as messenger molecules that bind to receptors on cell membranes, altering their shape and initiating a cascade of biological responses through second messengers.

Examples of Pheromonal Use in Nature

• Chiloglottis trapeziformis: Uses wasp pheromones to attract pollinators.
• Ophrys exaltata: Mimics bee pheromones with a chemical mixture that includes:
  • $(Z)-7-hexacosene$
  • $(Z)-7-pentacosene$
  • $(Z)-7-tricosene$
• Female Dogs: Secrete methyl paraben, a substance that signals readiness to mate.
• Androstenone: Present in truffles and boars, used in products that enhance attraction.

Human Pheromones

• Presence in Humans: Androstenone found in male sweat has been shown to relax women.
• Study Findings: Research indicates that male underarm secretions can affect women's hormonal cycles and mood positively.
  • Extracts from male secretions altered the pulsatile secretion of luteinizing hormone (LH), which can influence menstrual cycles.

Love and Reward System

• Romantic Love: Stimulates the brain's reward system, leading to the release of phenethylamine (PEA) which increases dopamine levels.
  • Effects similar to additives like cocaine.
  • Found in chocolate but dietary PEA cannot cross the blood-brain barrier.

Attachment and Bonding

• Hormones Involved:
  • Oxytocin: Released during labor and lactation; facilitates bonding and attachment.
  • Vasopressin: Plays a role in long-term relationships among mammals.
• Behavior: Prairie voles that produce oxytocin are known to be monogamous, while mountain voles lack oxytocin receptors and do not form stable pair bonds.

The Role of Aphrodisiacs

• Definition: Substances that purportedly increase sexual desire and performance.
• Common substances include:
  • Rhino horn
  • Common stinkhorn
  • Oysters
  • Hormonal Influence: Mention of testosterone's impact on sex drive in both genders.

Drugs Affecting Sexual Function

• Addyi (Flibanserin): Approved for hypoactive sexual desire in women after several failed attempts due to minimal effective results over placebo.
• Viagra: Initially tested for blood pressure control but was effective in treating erectile dysfunction by inhibiting phosphodiesterase 5, enhancing blood flow.
• Ecstasy and Alcohol: Mentioned as social drugs that can alter sexual behavior but excessive amounts may impair sexual performance.