Intro | Presynaptic Neuron | Postsynaptic Neuron | Terminal Button | Axon | Neural Impulse | Synaptic Vesicles | Neurotransmitter Molecules | Cell Membrane | Transmitter does not fit at receptor | Transmitter fits receptor | Receptor Sites | Synaptic Cleft
Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test
Part 3: Multiple-Choice Self-Test
7. Neurotransmitter Molecules are specialized to transmit information from one neuron to the next via release into the synaptic cleft. Neurotransmitters control all aspects of our behavior, thoughts, and emotions. At least 10 different molecules qualify as neurotransmitters. They work at specific synapses containing the complementary postsynaptic receptor sites. Examples of major neurotransmitters found in the brain are acetylcholine, the biogenic amines (norepinephrine, epinephrine, and serotonin), gamma-aminobutyric acid (GABA), and the endorphins. Acetylcholine works at the neuromuscular junction to control motor movement. In the brain, acetylcholine plays a special role in the formation of memories, attention, and arousal. The biogenic amines are very important for the regulation of mood, mechanisms of arousal and attention while awake, and maintaining the daily sleep-wake cycle. An imbalance in the level of dopamine is associated with the motor disorder, Parkinson's Disease, and with schizophrenia. GABA produces only inhibitory postsynaptic potentials (PSP's) in the brain, and acts to lower the level of electrical activity and anxiety. The endorphins resemble opiate drugs, and as neurotransmitters or neuromodulators they regulate feelings of pleasure, pain, and hunger. The activity of neurotransmitters may be affected by other chemicals in the brain such as neuromodulators (which modulate the activity of specific neurotransmitters), prescription or recreational drugs, disease, stress, and diet. An agonist neuromodulator mimics the natural action of a neurotransmitter, whereas an antagonist neuromodulator opposes the action of a neurotransmitter.