Neurotransmitters KAR Flashcards
What neurotransmitter wakes you?
Histamine
Anti-Histamine thus makes you drowsy
What neurotransmitter is made in the tuberomamillary nucleus?
Histamine, damage to this area decreases Histamine release
Aside from Histamine, what other neurotransmitter helps with arousal and wakefulness?
acetylcholine (ACh)
Where are the central neuron locations for ACh?
Midbrain (thalamus and hypothalamus), pons, striatum
What is ACh crucial for?
Consciousness (but not awareness!)
Control of voluntary motion
Initiation of REM
What moves ACh into vesicles?
VAchT protein
Where is acetylcholinesterase bound/located?
Post-synaptic membrane
What are the inhibitory AA neurotransmitters?
GABA and Glycine
Where is GABA found in the CNS?
Higher than glycine, cortex, cerebellum, retina
What is the function of GABA?
MAJOR inh neurotransmitter in higher CNS
Critical or consciousness and awareness
Controls voluntary motion
What causes Stiff Man Syndrome?
glutamate decarboxylase (GAD) is destroyed by the immune system, depriving the body of an essential inhibitory neurotransmitter leading to excessive muscle contraction (spasms and cramps) and eventually tetanus
What breaks down GABA in the synapse?
GABA transaminase
What happens when the GABA-A (ionotropic) receptor is stimulated?
Cl enters the cell leading to hyperpolarization
Benzodiazapines bind these Rs and cause relaxation
May be activated in cortex by anesthesia
What happens when GABA-B (metabotropic) Rs are activated?
Gq activity blocked, Gi activity upregulated
Ca levels drop (Gq blocked)
K levels increase (adenyly cyclase blocked)
Overall affect is hyperpolarization
Where is Glycine predominantly found?
Lower part of CNS in the SC
What is the action of Glycine?
Mediates spinal inhibitions (modification of reflexes)
What are the opioid peptides?
Tachykinins (Substance P), opioids, endocannabinoids, somatostatin
What are the opioid peptides?
Endorphins (endogenous morphine), enkephalins, dynorphins, nociceptin
All can act on opioid Rs so it’s hard to tell what’s at work at any given time
Where are opioids produced in the body?
Hypothalamus, medulla
What are the functions of opioids?
Reduces nociceptive input (pain input to the brain, reducing pain), modification of mood via the limbic system
What limits the actions of opioids?
Enkephalinase A/B, aminopeptidase
What R’s do opioids bind to?
Gi R’s that inhibit adenyly cyclase (AC), all are metabotropic
Mu: analgesia, respiratory depression, euphoria, sedation, constip
Kappa: analgesia, dysphoria (bad)
Delta: analgesia
Mu increases K to hyperpolarize, Kappa and delta decrease Ca to hyperpolarize (think about Ca toxicity and unregulated neuron stimulation)
What is the endocannabinoid framework made of?
Arachidonic acid
Arachidonic acid is also used to make prostaglandins!
Where are endocannabinoids made?
Basal ganglia, SC, neocortex
What do endocannabinoids do?
Basal ganglia: affect and motor
SC: nociception (pain perception)
Neocortex (neuroprotective)
Hippocampus: negatively effects memory
What are the endocannabinoid R’s?
CB-1 and CB-2
Where are CB-1 R’s located?
On axons and presynaptic terminals of EAA and GABA synapses
Binds Gi R’s and reduces neurotransmitter release effecting neural processing
Where are CB-2 R’s found?
Found on microglia, NOT neurons
Anti-inflammatory, can effect immune system and gut
May cause macrophages to remove B-amyloid
What is synthesized by the Raphe Nuclei?
Serotonin
