Skip to content - Dopamine Dopamine is a catecholamine central to motivation, reward learning, and movement. Its mesolimbic pathway encodes reward prediction and drives goal-directed behavior — the circuit hijacked in addiction — while the nigrostriatal pathway enables smooth voluntary movement and degenerates in Parkinson’s disease. In the prefrontal cortex it supports working memory and executive function; dysregulation is implicated in schizophrenia and ADHD. 📚 244 📄 694 🎙️ 72
- Serotonin (5-HT) Serotonin is a monoamine that regulates mood, emotion, appetite, and sleep, and is the primary target of SSRI antidepressants. Although famous for its brain role, roughly 90% of the body’s serotonin resides in the gut, where it governs motility. It shapes emotional stability, impulse control, and satiety, and dysregulation is implicated in depression, anxiety, and OCD. 📚 93 📄 465 🎙️ 23
- Glutamate Glutamate is the brain’s main excitatory neurotransmitter, driving most fast signaling and, through NMDA and AMPA receptors, the synaptic plasticity that underlies learning and memory. Its tight regulation is essential: too little impairs cognition, while excess causes excitotoxicity implicated in stroke, traumatic brain injury, ALS, and neurodegeneration. It is held in balance against inhibitory GABA. 📚 123 📄 362 🎙️ 42
- GABA (Gamma-Aminobutyric Acid) GABA is the brain’s principal inhibitory neurotransmitter, counterbalancing excitatory glutamate to keep neural activity stable. By opening chloride channels it quiets neurons, producing calming, anti-anxiety, and sedative effects — the mechanism enhanced by benzodiazepines, alcohol, and many sleep aids. Adequate GABAergic tone is essential for preventing seizures and regulating anxiety, sleep, and muscle tone. 📚 55 📄 293 🎙️ 11
- Norepinephrine (Noradrenaline) Norepinephrine is a catecholamine that functions as both neurotransmitter and stress hormone, central to arousal, alertness, and the fight-or-flight response. From the locus coeruleus it sharpens attention, vigilance, and mood, while in the sympathetic nervous system it raises heart rate and blood pressure. Its dysregulation is implicated in depression, anxiety, PTSD, and ADHD. 📚 50 📄 272 🎙️ 10
- Acetylcholine (ACh) Acetylcholine is a major neurotransmitter of both the central and peripheral nervous systems. At the neuromuscular junction it triggers voluntary muscle contraction, and as the primary transmitter of the parasympathetic ("rest and digest") system it slows the heart and stimulates digestion. In the brain it is central to attention, learning, and memory — the cholinergic neurons lost early in Alzheimer’s disease — acting through nicotinic and muscarinic receptors. 📚 53 📄 209 🎙️ 19
- Endorphins Endorphins are endogenous opioid peptides released in response to pain, stress, and exertion, acting at mu-opioid receptors to blunt pain and produce well-being. They underlie phenomena such as the "runner’s high" and pain relief during injury, and interact with the brain’s reward circuitry. They are a core part of the body’s natural analgesic and mood-regulating system. 📚 27 📄 148 🎙️ 2
- Oxytocin Oxytocin is a peptide acting as both hormone and neurotransmitter, central to social bonding, trust, and attachment. Released during childbirth, breastfeeding, touch, and intimacy, it promotes maternal behavior, pair bonding, and empathy, and buffers stress. Beyond social behavior it drives uterine contractions and milk ejection, tying reproductive physiology to social connection. 📚 35 📄 117 🎙️ 8
- Endocannabinoids (Anandamide, 2-AG) Endocannabinoids such as anandamide and 2-AG are lipid signaling molecules that act "backward" across synapses to dampen neurotransmitter release, fine-tuning excitability. Through CB1 and CB2 receptors — the same targets as THC — they regulate appetite, pain, mood, stress, and memory, and mediate effects like exercise-induced euphoria. The system broadly serves to restore balance after neural activity. 📚 1 📄 53 🎙️ 0
- Neuropeptide Y (NPY) Neuropeptide Y is one of the most abundant peptides in the brain, best known for powerfully stimulating appetite and regulating energy balance. It also exerts strong anti-anxiety and stress-buffering effects that promote resilience, and it influences circadian rhythm, blood pressure, and seizure threshold. It acts broadly as a counter-regulator that dampens stress and restores homeostasis. 📚 4 📄 39 🎙️ 2
- Epinephrine (Adrenaline) Epinephrine (adrenaline) is a catecholamine that acts as both hormone and neurotransmitter, driving the acute "fight-or-flight" response. Released from the adrenal medulla, it raises heart rate, blood pressure, and blood glucose and redirects blood flow to muscles. In the brain and sympathetic nervous system it heightens arousal and vigilance during stress and emergencies. 📚 4 📄 33 🎙️ 1
- Vasopressin (ADH) Vasopressin (antidiuretic hormone) primarily regulates water balance, prompting the kidneys to conserve water, and raises blood pressure by constricting blood vessels. As a brain neurotransmitter it also shapes social behavior, pair bonding, aggression, and stress responses, complementing oxytocin. It links fluid and cardiovascular homeostasis with social and stress physiology. 📚 7 📄 24 🎙️ 2
- Histamine Histamine is best known for allergy and inflammation, but in the brain it is a neurotransmitter that promotes wakefulness and arousal. Neurons of the tuberomammillary nucleus release it to sustain alertness — which is why antihistamines that cross into the brain cause drowsiness. It also influences appetite, learning, and the body’s immune and gastric-acid responses. 📚 3 📄 29 🎙️ 2
- Nitric Oxide (NO) Nitric oxide is an unusual gaseous signaling molecule that diffuses freely across membranes rather than acting at classical receptors. In blood vessels it drives relaxation and increased blood flow (including in the brain and during erection), and in the nervous system it acts as a retrograde messenger supporting synaptic plasticity and learning. It also contributes to immune defense. 📚 2 📄 25 🎙️ 0
- Aspartate Aspartate is an amino acid that acts as an excitatory neurotransmitter, closely related to glutamate and signaling largely through NMDA receptors. It contributes to fast excitatory transmission and to the synaptic plasticity underlying learning, and also participates in core metabolic pathways such as the urea and citric-acid cycles. Excess excitatory signaling can contribute to excitotoxic neuronal injury. 📚 0 📄 29 🎙️ 0
- Adenosine Adenosine is a neuromodulator that accumulates during waking hours and promotes sleep, serving as the brain’s marker of metabolic "tiredness." By dampening arousal-promoting neurons it builds sleep pressure across the day — the effect caffeine blocks to produce alertness. It also regulates cerebral blood flow and helps protect neurons during metabolic stress. 📚 3 📄 19 🎙️ 0
- Enkephalins Enkephalins are small endogenous opioid peptides that modulate pain and emotion through delta- and mu-opioid receptors. Widely distributed in the brain, spinal cord, and gut, they dampen pain signaling and influence mood, reward, and stress. Together with endorphins and dynorphins they make up the body’s opioid peptide system. 📚 0 📄 21 🎙️ 0
- Glycine Glycine is the simplest amino acid and plays a dual role: it is a major inhibitory neurotransmitter in the spinal cord and brainstem, controlling reflexes and motor rhythm, and a required co-agonist at excitatory NMDA receptors in the brain. It thus contributes to motor control and reflex coordination as well as, via NMDA, cognition, and has been studied for effects on sleep quality. 📚 0 📄 21 🎙️ 1
- Substance P Substance P is a neuropeptide that plays a key role in transmitting pain and signaling inflammation, acting mainly at neurokinin-1 (NK1) receptors. Released by sensory neurons, it amplifies pain perception and drives the neurogenic component of inflammation, and it also influences mood, stress, and nausea — NK1 antagonists are used as anti-nausea drugs. 📚 2 📄 9 🎙️ 0
- Dynorphins Dynorphins are endogenous opioid peptides acting mainly at kappa-opioid receptors. Unlike the euphoria-linked endorphins, dynorphin signaling tends to produce dysphoria and stress responses, and it contributes to pain modulation, mood, and the negative-affect states that reinforce addiction. They form one arm of the body’s broader opioid system regulating pain and emotion. 📚 0 📄 4 🎙️ 0
- ATP (Adenosine Triphosphate) ATP is best known as the cell’s energy currency, but it is also released as a fast excitatory neurotransmitter and co-transmitter, signaling through purinergic (P2X/P2Y) receptors. In the nervous system it modulates pain signaling, autonomic control, and communication between neurons and glia. Its breakdown product, adenosine, then acts as an inhibitory, sleep-promoting modulator. 📚 0 📄 1 🎙️ 0