Neurotransmitters in the Nervous System -----TYPES OF NEUROTRANSMITTERS Flashcards
Causes skeletal muscle contraction (excitatory)
Acetylcholine (ACh)
Controls sympathetic effects on organs— Effects are either excitatory or inhibitory based on
whether the organ contains more alpha or beta receptors.
Noradrenalin/Norepinephrine (NA/NE)
Inhibits/suppresses skeletal muscle contractions
Dopamine
Controls Sleep/Wake Cycle
Serotonin
Excitatory NT used solely within the CNS
Glutamate
Inhibitory NT used solely within the CNS
GABA (gamma-aminobutyric acid)
Action potentials caused by this NT are interpreted by the brain as pain
Substance P
Natural painkillers that block pain sensations
Endorphins and Enkephalins
Excitatory in ganglia
Acetylcholine (ACh)
Emotions—Low levels can cause clinical depression
Noradrenalin/Norepinephrine (NA/NE)
Emotions—Involved in pleasure, reward, motivation
When released in response to an activity, dopamine reinforces that behavior.
Dopamine
Emotions—Low levels can cause clinical depression, anxiety, obsessions & compulsions
Serotonin
Especially important in learning and memory formation
Glutamate
Epilepsy Treatment—Anticonvulsants ↑ GABA release. This suppresses epileptic seizures
because GABA stops APs from being made.
GABA (gamma-aminobutyric acid)
Opioid Painkillers block its release & also activate natural painkiller pathways
What are some opioids?
Substance P
Opioid PKs: Morphine, Heroin, Oxycodone
Opioid Painkillers bind to their receptors
Endorphins and Enkephalins
Controls parasympathetic effects on organs–Effects are mostly excitatory (but can be inhibitory)
Acetylcholine (ACh)
Adrenergic Receptors, found in all organs, are divided into two types: alpha (α) & beta (β).
Noradrenalin/Norepinephrine (NA/NE)
Dopamine reuptake blocked by drug. Dopamine remains in synapses, flooding brain, stays active
for long periods, causing extreme “high.”
Addiction & Dopamine Dysregulation:
Several antidepressants are SSRIs: Selective Serotonin Reuptake Inhibitors
What are the names of the antidepressants?
Serotonin
Lexapro, Celexa, Zoloft
Excitotoxicity: Is toxic to neurons—literally “excites” them to death
Glutamate
Sedatives enhance GABA’s effects: Alcohol, Benzodiazepines (Valium & Xanax), Barbiturates
GABA (gamma-aminobutyric acid)
Cholinergic Receptors are divided into two types:
Nicotinic receptors are found in both skeletal muscle and in ganglia.
Muscarinic receptors are found in all organs
Major “Feel-Good” NT–Drugs that give a “high” can increase its effects in 3 ways:
1) Increase the amount released from presynaptic knob
2) Inhibit the MAO enzyme (that breaks it down in the synapse)
3) Block reuptake (reabsorption into presynaptic knob)