Neurotransmitters & Neuromodulators

Neurochemicals

Neurochemicals are chemical substances in the brain that transmit neural information within the nervous system.

Synaptic transmission

Synaptic transmission is the chemical conveyance of neural information between two neurons across a neural synapse. As such, our brain’s method of information transmission is an electrochemical one.

The process of synaptic transmission

• Neurochemicals are produced in the axon terminals of the presynaptic neuron

• Neurochemicals are released from the axon terminals of the presynaptic neuron into the synaptic gap

• Neurochemicals bind to receptor sites on the dendrites of the postsynaptic neuron

• Neurochemicals affect the postsynaptic neuron, either triggering or inhibiting a neural impulse

Neurotransmitters

Neurotransmitters are chemical substances that carry a message to one or two other postsynaptic neurons (or to cells in muscles, organs or other tissues).

Reuptake

Reuptake is the process in which neurotransmitters that don't bind to receptor sites are reabsorbed into the terminal buttons of the presynaptic neuron.

Glutamate

Glutamate is the main excitatory neurotransmitter in the nervous system. It increases the likelihood of presynaptic neurons firing an action potential.

• Information transmission

• Enhanced learning and memory

• Thought and movement

GABA (gamma-aminobutyric acid)

GABA is the main inhibitory neurotransmitter in the nervous system. It decreases the likelihood of a postsynaptic neuron firing an action potential.

• Regulating postsynaptic activation in neural pathways, preventative the overexcitation of neurons

• Maintaining neurotransmission at an optimum level

• Reduces anxiety and prevents seizures

• Inhibits and fine-tunes information transmission

Neuromodulators

Neuromodulators are chemical molecules that have an effect on multiple postsynaptic neurons. This type of neurochemical modulates neural activity on a larger scale than neurotransmitters.

Dopamine

Dopamine is a neuromodulator primarily responsible for voluntary motor movement, the experience of pleasure, motivation and reward-based learning.

Although primarily an excitatory neurotransmitter, dopamine can have either an excitatory effect at one location or inhibitory effect at another location, depending on the type of receptors that are present.

Serotonin

Serotonin is a neuromodulator primarily responsible for the regulation of mood and sleep.

Serotonin has an inhibitory effect on the postsynaptic neuron.