Neuronal Signalling in the context of CNS Disorders Flashcards
What are the different types of transmembrane transport?
Simple diffusion
Facilitated diffusion
Primary active transport
Secondary active transport
What is simple diffusion?
Free movement of ions from high to low conc
NO carriers
What is facilitated diffusion?
Diffusion helped by transmembrane carriers + ion channels
What is primary active transport?
Movement of ions from a low conc to a high conc via ion pumps, using ATP
What is secondary active transport?
Uses free energy of the electrochemical gradient for one component to transport another against its chemical gradient
What are voltage-gated ion channels?
Transmembrane proteins that form ion channels that are activated by changes in the electrical membrane
What are ligand-gated ion channels?
Membrane proteins that open by binding of neurotransmitter, hormone or drug
What are G protein coupled receptors?
Detect molecules outside the cell + activate internal signal transduction pathways
What is an example of primary active transport?
Na+/K+-ATPase
What is an example of secondary active transport?
Na+/Ca2+-exchanger
What is the charge inside the cell?
Negative
What is the charge outside the cell?
Positive
What is depolarisation?
Reduction of charge
What is the depolarisation a result of?
Increased influx of Na+ +/or Ca2+
= increased neuronal excitability
What is the resting potential value?
-70mV
What is hyperpolarisation?
Increase of charge
What is hyperpolarisation a result of?
Increased efflux of K+
= decreased neuronal excitability
What is an action potential?
Change in voltage spontaneously or as a result of a stimulus
How many phases is there?
0-4
What happens in phase 0?
Resting membrane potential
Slow depolarisation
What happens in phase 1?
Rapid depolarisation
What happens in phase 2?
Repolarisation
What happens in phase 3?
Afterhyperpolarisation
What happens in phase 4?
Resting membrane potential
Slow depolarisation
Where is noradrenaline synthesised?
Adrenal medulla in sympathetic nervous system
Describe the pathway formation of noradrenaline
From dopamine to noradrenaline (by dopamine beta-mono-oxygenase)
Which diseases are associated with reduced noradrenaline?
Depression
Poor memory
Lack of energy, motivation + concentration
Which diseases are associated with increased noradrenaline?
Increased BP
Increased HR
Hyperactivity
Anxiety + stress
Irritability + insomnia
Where is dopamine synthesised?
Neurons + cells in the medulla of the adrenal glands
Which diseases are associated with reduced dopamine?
Parkinson’s disease
ADHD
Narcolepsy
Depression
Schizophrenia
What is Parkinson’s disease (PD)?
Degeneration of dopamine neurons
What are the symptoms of PD?
Involuntary shaking
Slow movement (bradykinesia)
Stiff + flexible muscles
Where is serotonin synthesised?
Midbrain + hypothalamus
Which diseases are associated with serotonin dysfunction?
Depression
confusion
Agitation
Headaches
Increase BP
N&V
Diarrhoea
Which diseases are associated with decreased Ach?
Alzheimer’s disease (AD)
Parkinson’s
Myasthenia gravis
What is AD?
Progressive neurological disorder, characterised by loss of memory or other intellectual abilities
