Ch. 3

Electrical potential

The difference in electrical charge between the interior and exterior of a neuron.

Local potential

A reduction in the difference of positive and negative charges across the neuronal membrane, leading to depolarization.

Depolarization

A change in membrane potential that makes the interior of the neuron less negative, leading to excitatory postsynaptic potentials (EPSP).

Hyperpolarization

An increase in the difference between the positive and negative charges on each side of the neuronal membrane, resulting in inhibitory postsynaptic potentials (IPSP).

Voltage Gated Ion Channels

Channels whose opening and closing can change resting potentials, particularly when Na+ channels open during depolarization.

Ionotropic receptors

Receptors that are ion channels which open immediately upon binding a neurotransmitter.

Metabotropic receptors

Receptors that use G proteins to activate second messenger systems, leading to slower transmission effects.

Presynaptic receptors

Receptors that relay signals for the axon terminal to assess synaptic space availability.

Autoreceptors

Presynaptic receptors activated by the neurotransmitter released by its own neuron, usually inhibitory.

Heteroreceptors

Presynaptic receptors activated by neurotransmitters from a different neuron.

Glutamate

An excitatory neurotransmitter with ionotropic receptors, including NMDA.

GABA

An inhibitory neurotransmitter that has both ionotropic and metabotropic receptors.

Dopamine

A monoamine neurotransmitter with both excitatory and inhibitory effects, depending on receptor type.

Mesolimbic pathway

Dopamine pathway that originates in the ventral tegmental area and terminates in the nucleus accumbens.

Nigrostriatal pathway

Dopamine pathway originating in the substantia nigra and terminating in the basal ganglia.

Noradrenergic neurons

Neurons that release norepinephrine, originating from the locus coeruleus.

Serotonin

An indolamine neurotransmitter that has a complex mix of inhibitory and excitatory receptor effects.

Acetylcholine

A major neurotransmitter for skeletal muscles and the parasympathetic nervous system, acting through nicotinic and muscarinic receptors.