1.  chemicals released by vesicles in sending neuron  travel across the synapse and bind to receptor sites on receiving neuron 2 TYPES = EXCITATORY = stimulate the brain, increase the likelihood that the neuron will fire an action potential INHIBITORY = calm the brain, balance mood & are depleted when excitatory are overactive

2. Neurotransmitters bind to the receptors of the receiving neuron in a “key-lock mechanism”.

3.  Serotonin  various functions = body temp., sleep, mood, appetite, and pain  Low levels =implicated in depression & probs with immune syst.  High = Serotonin Syndrome  stimulant medications or caffeine in your daily regimen can cause a depletion of serotonin

4.  Norepinephrine (AKA Noradreneline)  Prepares you for action  important for attentiveness, emotions, sleeping, dreaming, and learning  causes blood vessels to contract & heart rate to increase  GABA  Gamma-Amino Butyric Acid  An inhibitory neurotransmitter  “nature’s VALIUM-like substance”  Related probs = anxiety, seizures, Huntington’s disease  Valium and similar antianxiety drugs work at GABA synapses

5.  Dopamine  main focus neurotransmitter  Affects neurons associated with voluntary movement  role in learning, memory, and emotions  Loss of dopamine-producing cells = Parkinson’s Disease  Excess = focusing issues, less motivation, schizophrenia  Stimulants (ex: cocaine, meds for ADD/ADHD, caffeine) cause dopamine to be pushed into the synapse so that focus is improved  BUT cause a depletion over time  Acetylcholine  triggers muscle contraction  important role in arousal and attention  Loss = linked to Alzheimer’s Disease

6.  Endorphins  linked to pain control and to pleasure  Reduce pain by inhibiting or “turning down” neurons that transmit pain information  natural, opiate-like neurotransmitters “morphine within”

7.  Dopamine pathways are involved with diseases such as Parkinson’s disease  caused by a deterioration of brain neuron’s that produce dopamine (it is still unknown why this occurs)  Although not the sole cause of schizophrenia, dopamine unbalance is consistently seen found in patients with schizophrenia  Drugs that prevent dopamine from binding to receptors reduce the symptoms of schizophrenia

10.  Agonist  Increases production  Activates the neuron receptor that it attaches to  Antagonist  Decreases production  Deactivates the neuron receptor that it attaches to