Neuro Science  

 

 

 

 

 

Neuro Transmitters

 

Neuro Transmitters are special type of chemicals that functions as a coveying material which transfer a signal from one neuron to another neuron. More specifically, these chemical (called neuro transmitter) is released from a part of one neuron (pre-synaptic neuron), swim through space called synaptic gap and reaches to the destination called a part of another neuron (post-synaptic neuron).

In this note I will introduce a list of neurotransmitters and the list will get longer as I learn more on this subject. Don't try to memorize everything in the list. It would not be much of use if you just memorize and it will be confusing as well since some neurotransmitters work differently depending on which part of the brain (or nerveous system) they are being used.  Use this page as a mini dictionary or cheatsheet whenever you want to check about any specific neurotransmitter while you are reading text or watching lectures.

 

 

 

List of Neurotransmitters

 

Neurotransmitter

Mode of Functions

Chemical Type

Glutamate (Glu)

Excitatory

Amino Acid

Acetylcholine (ACh)

Excitatory/Modulator

 

Histamine

Excitatory/Modulator

Monoamine

Dopamine (DA)

Excitatory/Inhibitory/Modulator

Monoamine

Norepinephrine (NE); a.k.a noradrenaline(NAd)

Excitatory/Modulator

Monoamine

Epinephrine (Epi); a.k.a adrenaline(Ad)

Excitatory

Monoamine

gamma-Aminobutyric acid (GABA)

Inhibitory

Amino Acid

Serotonin /5-hydroxytryptamine (5-HT)

Inhibitory/Modulator

Monoamine

L-Aspartate    
Glycine

Inhibitory

Amino Acid

D-Serine    
Endorphines  

Peptides

hormones from hypothalamus

hormone

 

Oxytocin (Oxt)

hormone

Peptides

Vasopressin; a.k.a antidiuretic hormone (ADH)

hormone

 

Adenosine  

Purine

Adenosine Triphosphate (ATP)  

Purine

Nitric oxide

 

Gasotransmitters

Carbon monoxide

 

Gasotransmitters

 

 

Acetylcholine

 

Image Source : PubChem

 

Functions in Peripheral Nervous System (PNS)

  • excitatory role leading to the voluntary activation of muscles
  • contraction of smooth muscles
  • dilation of blood vessels
  • slow heart rate
  • increase body secretions

 

Functions in Brain and Central Nervous System (CNS)

  • function as a neurotransmitter and a neuromodulator
  • involved in motivation, arousal, attention, learning, memory
  • promotes REM sleep

 

Medical Conditions related to Acetylcholine Dysfunction

  • Alzheimer's Disease
  • Parkinson's Disease
  • Myasthenia Gravis

 

Medications that affect Acetylcholine

  • Botox
  • ACheE(Acetylecholinesterase inhibitors
  • Anticholinergics

 

 

GABA (γ-Amino Butyric Acid)

 

Image Source : PubChem

 

Function :

  • an inhibitory neurotransmitter in central nervous system (main inhibitor in our brain)==> Opposite funtionality against Glutamate
  • When GABA binds to the receptor (GABA-A or GABA-B receptors), the responsiveness of the nerve cell decreases
  • In this way, GABA van slow down certain brain function that is thought to do followings :
    • Reduce stress
    • Relieve anxiety
    • Improve sleep

Medical Conditions related to decreased GABA level :

  • Anxiety and mood disorders.
  • Schizophrenia.
  • Autism spectrum disorder : : Decreased GABA is observed in the brain (Update on Brain Research in Autism)
  • Depression.
  • Epilepsy, seizures.

Medical Conditions related to GABA Imbalance :

  • Pyridoxine deficiency.
  • Hepatic encephalopathy.
  • Huntington disease.
  • Dystonia and spasticity.
  • Hypersomnia (excess daytime sleepiness or excessive time spent sleeping).

 

 

Glutamate

 

Image Source : PubChem

 

Function :

  • an excitatory neurotransmitter in central nervous system (main excitatory neurotransmittor in our brain) ==> Opposite funtionality against GABA
  • major excitatory neurotransmitter in the central nervous system.
  • present in 90% of the excitatory synapses
  • plays a key role in the plasticity of the nervous system
  • plays a role in glia-neuron signalling, along with two other neurotransmitters: D-serine and glycine

Medical Conditions related to Glutamate dysfunction :

Medical Condition related to too much Glutamate :

  • Parkinson's disease
  • Alzheimer's disease
  • Huntington's disease

Medical Conditions related to too little Glutamate

  • Trouble concentrating
  • Mental exhaustion
  • Insomnia
  • Low energy

 

 

Histamine

 

Image Source : PubChem

 

Function

  • Based on Receptor types
    • H1 receptors
      • regulate neuronal excitation in most brain regions (brain step, hypothalamus,thalamus, amygdala, septup, hippocampus, olfactory bulb, cortex
      • decrease the neuronal cells excitability and inhibits the cells firing in hippocampal pyramidal neurons
    • H2 receptors
      • mainly found in the basal ganglia, amygdala,hippocampus and cortex
      • regulate the neuronal physiology and plasticity
      • (in mice) a deficiency in H2R function cause cognitive deficits, impairment in hippocampla LTP, abnormalities in nociception
    • H3 receptors
      • act as a presynaptic heteroreceptor and release a variety of other transmitters (e.g, biogenic amines, acetylcholine, glutamate, GABA, peptidergic systems)
      • (in mice) the loss of H3R function is associated with behavioral state abnormalities (e.g, hyperphagia, late-onset obesity, increased insulin and leptin levels)
  • Based on locations
    • Thalamus and cerebral cortex : Arousal and wakefullness
    • Hypothalamus, glial cells and blood vessels: Homeostatic process (e.g, ood and water intake, hormones secretion, temperature regulation, among others)

 

 

Dopamine

 

Image Source : PubChem

 

Function

  • Plays a role as a reward center
  • involved in various functions as follows
  • Pleasurable reward and motivation
  • memory
  • movement
  • motivation
  • mood
  • attention
  • sleep and arousal
  • learning
  • lactation

 

Medical condition associated with low level of dompamine

  • ADHD (Attention Deficit Hyperactivity Disorder)
  • Parkinson's disease
  • Restless legs syndrome
  • Schizonphrenia

 

Medical condition associated with high level of dompamine

  • Mania
  • Obesity
  • Addiction

 

 

Serotonin / 5-hydroxytryptamine (5-HT)

 

Image Source : PubChem

 

Functions :

  • in brain
    • involved in mood stabilization(known as 'feel-good' chemical),cognition,learning,memory,sleep
    • effect on libido (high serotonine level may decrease sexual desire)
  • in other body parts
    • contributes to normal bowel function
    • reduce appetite when you are full
    • play a protective role in the gut
    • help blood clotting
    • influence bone density (high circulating serotonine level in the but might cause low bone density (e.g osteoporosis)

 

Signs of Low Serotonin :

  • Disrupted sleep patterns
  • Loss of appetite
  • Mood Changes
  • Trouble with memory and learning

 

 

NorAdrenaline / Nor Ephenephrine

 

Image Source : PubChem

 

Function

  • Made from nerve cells in the brainstep area and the arean near spinal cord
  • plays important roles in the fight-or-flight response
  • Increase alertness,arousal and attention
  • Contricts blood vessels, which helps maintain blood pressure under stress condition
  • affect sleep-wake cycle, mood and memory
  • reaches various organs as follows and cause rapid body reactions like fight-or-flight response
  • Eyes
  • Skin
  • Heart
  • Muscles
  • Liver
  • Airways
  • adrena gland

 

Medical Conditions related to low level of norepinephrine

  • Axiety
  • Depression
  • Attention deficit hyperacticity disorder (ADHD)
  • Headaches
  • Memory problems
  • Sleeping problems
  • Low blood pressure (hypotension)
  • Low blood sugar (hypoglycemia)
  • Changes in blood pressure, heart rate
  • Dopamine beta-hydroxylase deficiency

 

Medical Conditions related to high level of norepinephrine

  • High blood pressure (hypertension)
  • Rapid or irregular heartbeat
  • Excessive sweating
  • Cold or pale skin
  • Severe headaches
  • Nervous feeling, jitters
  • Pheochromocytoma (adrenal gland tumor)

 

 

Adrenaline /Ephenephrine

 

Image Source : PubChem

 

Function

  • plays both as a neurotransmitter and hormone but plays relatively small role as neurotransmitter
  • plays important roles in the fight-or-flight response
  • Increase alertness,arousal and attention
  • Contricts blood vessels, which helps maintain blood pressure under stress condition
  • affect sleep-wake cycle, mood and memory
  • reaches various organs as follows and cause rapid body reactions like fight-or-flight response
    • Eyes
    • Skin
    • Heart
    • Muscles
    • Liver
    • Airways
  • adrena gland

 

Medical Conditions related to low level of norepinephrine

  • Axiety
  • Depression
  • Attention deficit hyperacticity disorder (ADHD)
  • Headaches
  • Sleeping problems
  • Low blood sugar (hypoglycemia)
  • Changes in blood pressure, heart rate

 

Medical Conditions related to high level of norepinephrine

  • High blood pressure (hypertension)
  • Rapid or irregular heartbeat
  • Excessive sweating
  • Cold or pale skin
  • Severe headaches
  • Nervous feeling, jitters
  • Pheochromocytoma (adrenal gland tumor)

NOTE : Overall functionality of Nor-epinephrine may sound very similar to the functionality of Epinephrine and sound confusing. Check out the section 'What are the similarities and differences between epinephrine and norepinephrine?' of this document for clarification on similarity and differences between nor-epinephrine and apinephrine.

 

 

L-Aspartate

 

Image Source : PubChem

 

Function

  • structural homologue of glutamate, with one fewer methylene (-CH2) group in the sidechain
  • plays a role as the secondary excitatory neurotransmitter in the CNS

 

 

Glycine

 

Image Source : PubChem

 

Function

  • a major inhibitory neurotransmitter in the spinal cord and brainstem
  • coexists with GABA in many of these neurons
  • exerts fast postsynaptic inhibition that is important for control of excitability of motor neurons, auditory processing, pain transmission in the dorsal horn, and other functions
  • a coagonist of glutamate on NMDA receptors

 

 

D-Serine

 

Image Source : PubChem

 

 

 

Problems that are releated to Neurotransmitters

 

In order for Nuerotransmitters to function properly, they should be as follows :

  • They should be transmitted at right place, right amount and at right timing
  • They should be staying at the synaptic gap for right span of time
  • They should be taken back fast enough at the right timing

Most of the problems that are related to Neurotransmitters are because those transmitters does not work as listed above. Common types of Neurotransmitter related problems can be listed as in this document as below.

  • Neurons might not manufacture enough of a particular neurotransmitter
  • Neurotransmitters may be reabsorbed too quickly
  • Too many neurotransmitters may be deactivated by enzymes
  • Too much of a particular neurotransmitter may be released

 

 

 

Distribution of  Neurotransmitters in Brain

 

 

Image Source : Mapping neurotransmitter systems to the structural and functional organization of the human neocortex

 

 

 

Reference

 

 

 

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