Micro-anatomy (Neurotransmitters & Neuromodulators) (FS - Week 1) Flashcards
What is the function of the neurotransmitter Acetylcholine (Ach)?
Function - memory and learning
What receptors does Acetylcholine activate
Nicotinic
Muscarinic
What is the drug target of Acetylcholine
Alzheimer’s disease
What is the function of neurotransmitter Glutamate
Major excitatory
learning and memory and long-term potentiation
What is the drug target of glutamate
Alzheimer’s disease related to glutamate mediated excitotoxicity
What receptors does glutamate activate
- Ligand-gated ion channels
(AMPA, NMDA, Kainate) - GPCRs
(Group 1, 2, 3)
What is the function of GABA
major inhibitory
mediates neurotransmission in local circuit interneurons
What is the drug target of GABA
Anxiety disorders
What receptors does GABA activate
GABAa
GABAb
What is the neurotransmitter Dopamine’s function
- initiating voluntary movement
- reward and reinforcing behaviours
What is the drug target of dopamine
Parkinson’s disease
What receptors does dopamine activate
GPCRs
subtypes D1-D5
What is the function of serotonin
- sleep
- wakefulness
- mood
- emotional behaviours
What is a drug target of serotonin
depression
anxiety
What receptors does serotonin activate
GPCRs
5-HT1/2/4/5/6/7
(5-HT3 exempt as it’s a LGIC)
What is the function of noradrenaline
major transmitter in sympathetic nervous system
- attention
- arousal
- sleep
- wakefulness
What receptors does Noradrenaline activate
GPCRs
a-noradrenergic
b-noradrenergic
What is the drug target of noradrenaline
anxiety
What are neurohormones
chemical messengers that are produced and released by neurons to subsequently function as hormones
Oxytocin and vasopressin are examples of which type of neurohormones
protein and peptide hormones
Noradrenaline and dopamine are examples of which type of neurohormones
amino acids
Cortisol and aldosterone are examples of which type of neurohormones
steroid hormones
What is the peripheral function of oxytocin
acts on mammary glands to stimulate lactation
acts on the uterus to stimulate contractions
What is the peripheral function of vasopressin
acts on blood vessels to cause vasoconstriction
acts on kidneys to regulate water retention
What is meant by diffuse neuromodulatory systems
systems of the CNS that project widely and diffusely to large areas of the brain via modulatory neurotransmitters
What is the noradrenergic locus coeruleus
small nucleus located bilaterally in the pons with noradrenergic projections to vast parts of the CNS
What is the serotonergic raphe nuclei
a collection of nuclei located in the brainstem with serotonergic projections to the CNS
What is the dopaminergic substantia nigra
cell group located in the midbrain with dopaminergic projections to the striatum
What is the VTA (ventral tegmental area)
cell group lying closely to the substantia nigra with dopaminergic projections to the CNS
What does substantia nigra projections regulate
initiation and voluntary movement
What does the VTA projections regulate
reward and reinforcement behaviours
Cocaine is a psychostimulant. Describe its mechanism of action
- it is a non-competitive blocker of dopamine and noradrenaline transporters
- less dopamine and noradrenaline are taken up into the presynaptic terminal
- increased levels of dopamine and noradrenaline in the synaptic cleft = increased postsynaptic receptor activation
How does the psychostimulant cocaine cause addiction and dependence
results of enhanced dopaminergic neurotransmission originating from VTA - by short circuiting this pathway it reinforces drug seeking behaviour
