iPsychology

Neurotransmitters

1. Small Transmitter Molecules
2. Neurotransmitterb info

Quaternary Amine

        Acetylcholine ( Ach )

Biogenic Amines

1.  Monoamines
     ( Catecholamines ):

    Dopamine ( DA )

    Norepinephrine
    ( Noradrenaline,  NA )

    Epinephrine
    ( Adrenaline,  EP,  Ad )

2.  Indolamines:

    Serotonin
    ( 5HT, 
      5 Hydroxytryptamine )

    Histamine

Aminoacid Neurotransmitters

Glutamate ( Glutamic Acid )

Gamma-Amino-Butyric-
Acid ( GABA )

Glycine

ATP

Adenosine

Neuropeptide Transmitters

Opioid Peptides

1.  Enkephalins:

    A.   Met-Enkephalin

    B.   Leu-Enkephaline

2.  Endorphins:

    Beta-Endorphin

3.  Dynorphins:

    Dynorphin-A

Peptide Hormones

Oxytocin

Vasopressin

Substance-P

Cholecystokinin ( CCK )

Hypothalamic Releasing
Hormones

Lipids

Anandamide

Soluble Gases

Nitric Oxide ( NO )

Carbon Monoxide ( CO )

Classes of Neurotransmitters

• Acetylcholine [ACH] - 2 types of ACH receptors.
  • Nicotinic [receptor] - ACH bind to Nicotinic receptor. Opens up potassium and sodium channels to move back and forth in the post-synaptic cell membrane. Overall the cell will become more positive.
    • Fast EPSP
  • Muscarinic [receptor] -ACH binds to G-Protein. Subunit of G-protein breaks off and binds/affects the K+ ion channel and opens it up. The cell becomes more negative.
    • Slow IPSP
• Monoamines [catecholamines] - all use 2nd messenger systems [use other molecules to signal inside our cell- slow mechanisms]
  • Norepinephrine[NE] - type of NT. Nor adrenaline
    • Tyrosine [AA] -> Dopamine molecule -> NE -> put into vesicles -> NE binds to a G-protein -> subunit of G-protein breaks off -> subunit goes to adenalyse cylase protein in the post-synaptic membrane and increases synthesis of cAMP in the cell -> influences phosphokinase enzyme [add phosphate ion to ion channel] -> Slow EPSP.

• Serotonin - synthesized from Tryptophan (AA)
  • Amino Acid -> Serotonin
    • NT that affects mood and appetite
  • Drug class- SSRI - serotonin specific reuptake inhibitors.
    • Allows the serotonin to stay in the cleft longer and greater chance that the serotonin receptors will get hit with serotonin.
• Dopamine - synthesized from Tyrosine. Involved with Parkinson [dopamine levels decrease- tremors/shakes]
  • Try to supplement patients with L-Dopa

• Polypeptides (CCK) - involved with hunger

• Fatty Acids - We have lipids (endocanibinoids) that act like NT that stimulates hunger/memory.
• Gases (diffuses right through the membrane)- Nitric Oxide (Viagra= vasodilator- blood flow increases) and Carbon Monoxide are very fast NT because it quickly diffuses the membrane.

• Amino Acid - some amino acid act like neurotransmitters.
  • Ex. Glutamic Acid