Chapter 4 #1 Flashcards
Endogenous
Produced inside the body
Exogenous
Arising from outside the body
Are Neurotransmitters endo or exo genous?
Endogenous
Exocytosis
A cellular process that results in the release of a substance
Transporters
Specialized protein membrane component that returns transmitter molecules to the presynaptic neuron for reuse (reuptake)
Ionotropic receptors
“Fancy ion channel receptor” a receptor protein containing an ion channel that opens when the receptor is bound by an agonist
Metabotropic receptors
No ion channels. May when activated, use a G protein system to open nearby ion channels or to produce other cellular effects.
What are the qualifying characteristics of a neurotransmitter?
- Can be synthesized by presynaptic neurons and stored in axon terminals
- Released when action potential reaches terminals
- Recognized by receptors on postsynaptic membrane
- Causes change in postsynaptic cell
What is the effect of blocking the release of a neurotransmitter?
Interferes with the ability of the presynaptic cell to affect the postsynaptic cell.
What are the 4 major categories of neurotransmitters?
Amine, amino acid, peptide, and gasses.
Amine neurotransmitter
A neurotransmitter based on modifications of a single amino acid nucleus.
Amino acid neurotransmitter
A neurotransmitter that is itself an amino acid.
What are some examples of amino acid neurotransmitter?
GABA, glycine, and glutamate
What are some examples of amine neurotransmitters?
Acetylcholine, serotonin, and dopamine
Peptide neurotransmitter
Also called neuropeptide. Neurotransmitter consisting if a short chain of amino acids.
What are some examples of peptide neurotransmitters?
Endorphins, oxytocin
Gas neurotransmitter
Neurotransmitter that is a soluble gas.
What are some examples of gas neurotransmitters?
Nitric oxide and carbon monoxide
Acetylcholine (ACh)
Neurotransmitter found in the autonomic nervous system, motor system, and throughout the brain. (Basal forebrain)
Cholinergic
Referring to cells that use acetylcholine as their synaptic transmitter
Loss of Cholinergic neurons refers to
Alzheimer’s disease (learning and memory)
Dopamine (DA)
A mono amine neurotransmitter found in the midbrain (especially the substantia nigra) and the basal forebrain
Dopaminergic
Referring to cells that use dopamine and there synaptic transmitter
Substantia nigra
Brainstem structure that innervates the basal ganglia and is responsible for all dopaminergic projections
What are the 2 main dopaminergic projections?
Mesostriatal pathway and mesolimbocortical pathway
What is the effect of damage to Mesostriatal dopaminergic neurons?
Profound movement problems such as Parkinson’s
The mesolimbocortical dopamine system is primarily important for?
Learning related to positive reinforcement or pleasure
Ventral tegmental area (VTA)
Portion of the midbrain that projects dopaminergic fibers to the nucleus accumbens (where the mesolimbocortical pathway originates)
Seratonergic
Referring to cells that use serotonin as their synaptic transmitter
Raphe nuclei
A string of nuclei in the midline of the midbrain and brainstem that contain most serotonergic neurons of the brain
Serotonin (5-HT)
Produced in the raphe nuclei and active throughout the brain.
What are some functions of serotonin?
Mood, vision, sex, anxiety, sleep, etc. used in depression and anxiety meds
Noradrenergic
Referring to cells using norepinephrine (noradrenaline) as a transmitter
What 2 regions of the brainstem is norepinephrine located?
The locus coeruleus and lateral tegmental area
Norepinephrine (noradrenaline)
Neurotransmitter produced and released by sympathetic postganglionic neurons to accelerate organ activity. It is also produced in the brainstem and found in projections throughout the brain
Locus coeruleus
A small nucleus in the brainstem whose neurons produce norepinephrine and modulate large areas of the forebrain
Lateral tegmental area
A brainstem region that provides some of the norepinephrine-containing projections of the brain
Glutamate
Amino acid transmitter, the most common excitatory transmitter
Gamma-aminobutyric acid (GABA)
A widely distributed amino acid transmitter and the main inhibitory transmitter in the mammalian nervous system
Opioid peptide
A type of endogenous peptide that mimics the effects of morphine in binding to opioid receptors and producing marked analgesia and reward
What is a main function of GABA?
Reduce anxiety, muscle relaxation, sleep, etc. Valium and Ativan
Where else are peptides that are found in the gut found?
Spinal cord and brain
Where are peptide hormones made?
The hypothalamus and pituitary
Some Neurons use gas molecules to do what?
Communicate info
What are the 2 most studied gas neurotransmitter
Nitric oxide and carbon monoxide
How are gas neurotransmitter different from chemical?
- Not in vesicles or axon terminals. Diffuses out of the neuron as produced
- Doesn’t involve post synaptic receptors, just diffuses inside to second messengers
- Can convey info back from post to presynaptic cell, or physically change the synapse
Retrograde transmitter
A neurotransmitter that diffuses from the postsynaptic neuron back to the presynaptic neuron. (Gasses)
