Endogenous Monoamine Systems SEM2 Flashcards
What are key monoamines in the CNS
Acetylcholine (ACh)
Dopamine (DA)
Noradrenaline (NA)
Serotonin
What are the major pathways where acetylcholine (ACh) is used in the brain
Nucleus basalis to cortex
Septal nucleus to hippocampus
In basal ganglia
What is the importance of the nucleus basalis to cortex pathway
Crucial for attention, learning and memory
What is the importance of the septal nucleus to hippocampus pathway
Important for memory formation and retrival
What is the importance of the basal ganglia pathway
Involved in motor control and cognitive functions
What is central acetylcholines relation to cognition
ACh enhances cognitive functions e.g attention and processing speed
Why is a result of inhibiting the breakdown of ACh
Increased processing speed because inhibiting the breakdown of ACh = more ACh present in synaptic cleft = ACh receptors are activated for longer duration of time
What are the main dopaminergic pathways in the brain
Nigrostriatal pathway
Mesocortical/mesolimbic pathway
Tuberohypophyseal pathway
What is the role of the nigrostriatal pathway
Regulates motor control
What is the role of the mesocortical/mesolimbic pathway
Mesocortical - influences cognitive function
Mesolimbic - role in reward, motivation and emotional behaviour
What is the role of the tuberohypophyseal pathway
Modulates hormone release at pituitary gland
What is amphetamine
Synthetic substance that promotes the release of neurotransmitters
what is the underlying cause in parkinsons disease
Degeneration of dopaminergic neurons in the nigrostriatal pathway -> causes motor symptoms e.g tremors
What is general treatment for parkinsons disease
L-DOPA is used to compensate for the reduced dopamine production
What is the role of L-DOPA
Used for its ability to convert into dopamine in the brain
What is the underlying cause of schizophrenia
Excess dopamine acitivity in the frontal cortext
What is the general treatment for schizophrenia
Antipsychotic medication e.g chlorpromazine - targets D2 dopamine receptors as antagonist to reduce dopamine activity
What does the noradrenergic pathways originate and course they follow
Pathway originates in the locus coeruleus (LC) neurons sent from LC to the hippocampus and cerebellum
What are the noradrenergic pathways involved in
Involved in the regulation of attention, learning, memory and emotional responses
What is another pathway which involves noradrenergic fibres
Reticular formation to spinal cord and hypothalamus pathway
How do noradrenergic pathways play a role in arousal
the release of noradrenaline (NA) leads to heightened awareness - ‘fight or flight’ response
How do noradrenergic pathways play a role in blood pressure regulation
The α2 agonist clonidine acts in brainstem to suppress the sympathetic pathways and reduce blood pressure - decreasing the release of noradrenaline (NA)
What is the pathway of serotonergic innervations of the CNS
Raphe nuclei project
What is the raphe nuclei project pathways course of transmission
Rostrally to cortext, hippocampus, basal ganglia, limbic system and hypothalamus
What is does the raphe nuclei project pathway regulate
Mood regulation
Sleep-wake cycles
Pain modulation
What are selective serotonin reuptake inhibitors (SSRIs) used for
Treatment of depression
What is the mechanism of SSRIs
SSRIs work by blocking re uptake of serotonin into presynaptic neurons -> increases amount of serotonin in synaptic cleft
