Mental Health and Monoamines Flashcards
What are the 4 types of Neurotransmitters?
Monoamines, peptides, Amino acids, and other
What is the function of amino acids and what are the main NTs?
They are important in most functions and include GABA, glutamate, and glycine
What is the function of monoamines and what are the main NTs?
They are important for attention, cognition, and emotion and include dopamine, epinephrine, and NE
What is the function of peptides and what are the main NTs?
They modulate pain and include endorphines
What is the function of the other category of NTs and what are the main NTs?
They are responsible for ANS and motor function, and acetylcholine is a main one.
Out of the amino acids, which NTs are excitatory/inhibitory?
Glutamate is excitatory, and GABA and glycine are inhibitory.
What is the role of neuron-neuron, point-point nervous communication?
It is precise
What are the 4 types of nervous system communication?
neuron-neuron
hypothalamic (lots of hormone effect)
ANS (one neuron -> direct to roughly 100 effector neurons)
Modulatory NT system (diffusion to surrounding neurons)
What are the 4 types of diffuse modulatory systems based off of their NT?
- Noradrenergic
- Serotonergic
- Dopaminergic
- Cholinergic
What do the 4 diffuse modulatory systems have in common? (4)
- They have a small set of neurons at the core
- They arise from the brain stem
- One neurons influences many others
- Synapses release transmitter molecules into the extracellular fluid
What is the part of the brain that is noradrenergic?
The Locus Coeruleus
Where is the locus coeruleus located?
The brainstem (pons)
What parts of the CNS are innervated by the locus coeruleus?
Spinal cord, cerebellum, neocortex, thalamus, hypothalamus
What are the catecholamines (That respond to catecholaminergic staining)?
Dopamine, NE, epinephrine
What functions are the noradrenergic coeruleus responsible for? (9)
- Attention
- arousal
- sleep/wake cycle
- learning
- memory
- anxiety
- pain
- mood
- brain metabolism
What causes the most rapid firing of noradrenergic neurons?
Wakeful response to new stimuli
What is the positive function of the Locus Coeruleus when exposed to NE?
Brain responsiveness, efficiency of sensory and motor processes
What is the serotonergic part of the brain called?
The Raphe Nuclei
Where are Raphe nuclei found and where do they project?
Around the midline of the brain, and they project to all levels of the CNS
When do Raphe Nuclei fire the most?
Waking hours
What systems in the brain are responsible for sleep/wake cycles and include the serotonergic Raphe Nuclei?
The reticular activating system, and the extrathalamic control modulatory system
What is the most important diffuse modulatory system for mood regulation?
The serotonergic raphe nuclei
What foods impact the serotonergic systems positively?
Carbs
What is the role of a MAO inhibitor?
It prevents the synaptic enzymatic destruction of NE, 5HT
What is the other name for serotonin as a NT?
5-HT
How do tricyclics differ from MAOIs?
Tricyclics block the reuptake of NE, 5HT
What is the type of antidepressant that blocks the reuptake of serotonin
SSRIs
What are the big precursors to Epinerphrine?
L-DOPA -> Dopamine -> Norepinephrine -> epinephrine
Where is the dopaminergic modulatory system located?
In the substantia nigra and the Ventral tegmental area are located in the midbrain
Where does the substantia nigra project to?
The striatum
Where does the ventral tegmental area project to?
The limbic and frontal cortical regions
What neurotransmitter has been recently found to initiate motor control and voluntary movement?
Dopamine
What condition is seen when monoamine blockers and given to a patient? What NT when injected can restore the patients condition?
Parkinsonism is seen, and the injection of dopamine can restore the patients function
Out of L-DOPA and norepinephrine, which one can pass through the BBB?
L-DOPA
Where do the cholinergic modulatory systems of the brain reside?
The basal forebrain and brain stem.
Where do cholinergic neurons project to?
Most of the brain, the cortex + hippocampus, and the thalamus + forebrain
What disease causes cholinergic neurons to die first?
Alzheimer’s
Is the treatment of the cholinergic system treatment for Alzheimer’s?
NO
What NT is affected by potent hallucinogenics?
Serotonin
What are the two stimulant drugs and what are their physiological effects?
Cocaine and amphetamine increases alertness and self-confidence, exhilaration and euphoria, and is an appetite suppressant
What are the NT effects of cocaine?
Cocaine targets dopamine reuptake
What are the NT effects of amphetamine?
It blocks NE and dopamine reuptake, and also stimulates dopamine release
What kind of disorder is SZ schizophrenia?
A developmental disorder
What are the two NTs that play a role in SZ, and how are they affected? How does this manifest in symptoms?
Glutamatergic receptors have hypofunction that cause early cognitive deficits, and altered dopaminergic homeostasis accounts for the more recognized SZ symptoms (hallucinations, delusion, disorganized behaviour)
What is the current treatment for SZ? Why is this considered an incomplete treatment?
Dopamine is targeted with antagonists, which is considered incomplete as this only treats the positive symptoms of SZ, not the negative ones
What are the two hypotheses of SZ?
The dopamine hypothesis: Psychotic episodes are triggered by excess triggering of Dopamine receptors
The Glutamate hypothesis: SZ reflects diminished activation of NMDA receptors in the brain
What are the two factors that will predispose a child to SZ?
It is heritable, and is also correlated to strong immune system response in the pregnant mother
What are the physiological differences found in SZ patients? (4)
Increased ventricle to brain ratio
Defects in cerebral cortex myelin sheaths
Abnormal neuron clusters
Alterations in chemical synaptic transmission mediated by DA and GLU
What are Neuroleptic drugs?
They are antipsychotics and block D2R (dopamine receptors)
How was the glutamate hypothesis of SZ discovered?
PCP (phencyclidine) inhibits NMDA (glutamate) receptors, which caused SZ-like symptoms
What two types of receptor are responsive to glutamate in the brain?
NMDA and AMPA
Where in the brain is dopaminergic activity and SZ seen to link?
In the mesolimbocortical pathway
What is the leading hypothesis for why extrapyramidal side effects are present along with neuroleptics.
EPS are thought to stem from blocking dopamine receptors in the striatum. Blocking dopamine receptors in the mesolimbocortical system, however, treats the positive SZ effects
What receptors do PCPs block?
Glutamate gated ion channels
What happened to mice who had PCPs given to them (blocked NMDA receptors)?
They avoided social contact.
