LECTURE 19 & 20: CNS Flashcards
Neurotransmitters
chemicals that allow communication between neurones, transmission across synapse
e.g. Ach, dopamine, serotonin
Neurodegenerative disease
disease of the CNS that is characterised by progressive loss of selected neurons in the brain
parkinsons disease
insidious onset of voluntary movement, muscle rigidity, postural abnormality and tremors
parkinsons is caused by
striatal deficiency of dopamine from neuronal degradation decreasing dopamine into neurostriatum
parkinsons treatment aims to
decrease Ach and increase Dopamine
dopamine drugs and Ach drug
1- dopamine precursor (L-dopa or levodopa)
2- inhibitor of dopamine metabolism (carbidopa)
3- dopamine agonist (pramopexole)
4- amantidine
5- Antimuscarinic drug (benzatropine)
what does amantidine do
blocks dopamine reuptake
how does antimuscarinic drug decrease Ach in parkinsons treatment
blocking M1 receptor, decreasing cholinergic activity, decreasing Ach
Alzheimers is a type of
dementia
3 distinguishing factors of alzheimers
1) accumulation of amyloid plaques between nerve cell of brain
2) formation of numerous neurofibrillary tangle
3) loss of cortical neurons (especially cholinergic neurons)
Alzheimers drugs
1) acetylcholinesterase inhibitors
2) NMDA receptor antagonists
Ach-esterase inhibitors in alzheimers treatment.
AND EXAMPLES
reversibly inhibit acetylcholinesterase to prevent breakdown of Ach, increasing transmission
doneprezil and galantamine
NMDA receptor antagonist in Alzheimers treatment
memantine
uncompetitive antagonist at glutamate receptor, dec neuronal excitotoxicity
motor neuron disease
group of related NGDs that affect motor neurons and therefore volunatry muscle control
drugs indicated for MND
riluzole
blocks TTX-sensitive channels which are linked to neurponal damage
allosterically binds to GABAA on post synaptic neuron prolonging survival for months
GABA
inhibitory amino acid in CNS
serotonin
excitatory monoamine neurotransmitter
noradrenaline
excitatory monoamine neurotransmitter
anxiety
feeling of dread, apprehension or uneasiness from unknown source
main mediators of anxiety symptoms
GABA, serotonin, noradrenaline and dopamine
drugs for anziety
benzodiazepines and barbiturate
benzodiazepines and barbiturate MOA
bind to allosteric site of GABAA receptors to enhance GABA binding
benzodiazepam eg
diazepam
barbiturate eg
thiopentone
Depression
low mood, lack of motivation and interest, aversion to activity
depression drugs
Selective serotonin reuptake inhibitor (SSRI)
serotonin-noradrenaline reuptake inhibitor (SNRI)
triacyclic antidepressant (TSA)
monoamine oxidase inhibitor
SSRI
blocks reuptake of serotonin into presynaptic cells - means serotonin remains longer in gap and can bind to receptor
SNRI and TSA
blocks reuptake of serotonin and noradrenaline into presynaptic cells - means serotonin and noradrenaline remains longer in gap and can bind to receptor
SSRI eg
citalopram
SNRI eg
venlafaxine
monoamine oxidase inhibitor
inhibit activity of monoamine oxidase A and or B - preventing breakdown of monoamine neurotransmitters (serotonin and noradrenaline)
patho cause of depression
not well understood but accepted to be insufficient monoamine neurotransmitters
monoamine neurotransmitters
serotonin, noradrenaline and dopamine
monoamine oxidase inhibitor eg
Phenelzine
why is monoamine oxidase inhibitor A better?
because acts for serotonin, noradrenaline and dopamine rather than just dopamine (B)
TCA eg
doxepin
