Chemical Neurotransmission Flashcards

Flashcards covering key vocabulary and concepts related to chemical neurotransmission, based on lecture notes.

Classic Synaptic Neurotransmission

The process by which electrical impulses are sent to the axon terminal of a presynaptic neuron when stimulated.

Presynaptic Neuron

The neuron that transmits its axon terminal to create a synaptic connection.

Mitochondria in the presynaptic neuron

supply energy for neurotransmission from that cell.

Small vesicles

Hold chemical neurotransmitters waiting to be released when the presynaptic neuron fires.

Synaptic Cleft

The gap between the presynaptic and postsynaptic neurons, which contains proteins and scaffolding.

Retrograde Neurotransmission

Occurs from postsynaptic to presynaptic neurons.

Endocannabinoids

Neurotransmitters produced in postsynaptic neurons, released, and diffused to presynaptic cannabinoid receptors.

Volume Neurotransmission

Neurotransmission that happens without a synapse, involving diffusion of neurotransmitters to locations far from the synapse.

Dopamine in the prefrontal cortex

There aren't many dopamine reuptake pumps. Therefore dopamine can diffuse to neighboring receptor sites

Monoamine Autoreceptors

Autoreceptors at the somatodendritic end of the neuron inhibit neurotransmitter release from the axonal end

Excitation–secretion coupling

An electrical impulse in the first (or presynaptic) neuron is converted into a chemical signal at the synapse

Chemical neurotransmission

initiates a series of signal transduction cascades that start with the first messenger of the neurotransmitter and continue with the second, third, fourth, and more messengers

Kinase

Adds phosphate groups to fourth-messenger proteins to create phosphoproteins.

Phosphatase

Removes phosphate groups from fourth-messenger phosphoproteins and thus reverses the actions of the third messenger on the left.

Four of the brain's most significant signal transduction cascades

G-protein-linked, ion channel-linked, hormone-linked, and neurotrophin-linked systems

Four components of a G-protein-linked second-messenger system

The neurotransmitter, often known as the first messenger, the G-protein-linked neurotransmitter receptor, a protein with seven transmembrane domains, a connecting protein, G protein, and an enzyme

Neurotransmitters

Alters gene expression

Learning and environmental experiences

Can change how specific genes are expressed, which can change how neuronal connections are formed.

Epigenetics

A mechanism that controls whether a particular gene produces its unique RNA and protein or if it is ignored or muted

Molecular gates

Are opened by acetylation and/or demethylation of histones, allowing transcription factors access to genes, thus activating them.

Molecular gates

Are closed by deacetylation and/or methylation provided by the methyl donor SAMe derived from L-methylfolate. This prevents access of transcription factors to genes, thus silencing them.

Alternative Splicing

When DNA is transcribed into messenger RNA (mRNA), this is called the primary transcript.

Alternative Splicing

mRNA is spliced, with certain sections reorganized or removed outright. This means that one gene can give rise to more than one protein

RNA Interference

RNA serve regulatory purposes rather than coding for protein synthesis, small hairpin RNA (shRNA) is transcribed from DNA but not translated into proteins.