Parkinson's disease Flashcards
True or False
At chemical synapses, nerve impulses arriving at the presynaptic axonal terminal result in NT release into the synaptic cleft between the neurons.
True
Postsynaptic receptors can be _____________, fast acting, or can be _______________, act through sceond messengers, slow acting.
ion channels
metabotropic receptors
NTs are syntheszied through ___________ reactions, usually in th neuorns that release them,
NTs are stored in __________ at (presynaptic / postsynaptic) terminals
After release and (presynpatic / postsynaptic) action, NTs are ______ from the synaptic cleft. (getting ready for another signal)
NTs are either ______________ or _________________.
chemical
vesicles at presynaptic
postsynaptic
cleared
reuptake (recycled) or metabolized (broken down)
How are NTs classified?
Based on their structure
mode of action
location
What are the two most common NTs for inotropic signalling in the brain?
Glutamate (+)
GABA (-)
True or False
Many NTs play a neuromodulatory role acting via metabotropic signaling that has varying effects.
A neuron has one primary NTs that is released and can be affected by different types of NTs based on the different types of receptors.
True
Synthesis usually starts from commonly occuring ________________ (e.g.) amino acids, regulated by ______________.
Some major NTs are part of the same synthesis cascade. What is an example?
Precursor molecules
enzymes expressed by neurons
Glutamine to glutramate to GABA
What are three ways in which an NT is cleared from synaptic cleft?
Diffusion
Active transport
degradation
Choose the best option
(diffusion / active transport / degradation )
Passive movement of NTs to other areas of extracellular space
diffusion
Choose the best option
(diffusion / active transport / degradation )
mediated by NT transproeters on neurons and/or glia
active transport
Choose the best option
(diffusion / active transport / degradation )
occurs via enzymes wither in synaptic cleft or intracellularly
degradation
Dopamine is synthesized in two steps from the amino acid tyrosine.
Tyrosine with Tyrosine hydroxylase makes __________
___________ with amino acid decarboxylase makes Dopamine.
DOPA (intermediatory molecule)
The ________________ mediates re-uptake of free dopamine in the sunaptic cleft back into the presynaptic terminal. (end of signal)
dopamine transporter
Doapimes is degraded by two enzymes (which are important targets for therapeutics)
Hint: One degraded intercellular and the other in the synaptic cleft
monoamine oxidase (MAO)
catechol-O-methyl transferase (COMT)
True or False
Dopamine mostly acts as a neuromodulator, via metabotropic receptors with effects that are slower and longer lasting than ionotropic effects.
True
There are multiple ascending neuromodulator systems in the brain that use distinct NTs, name at least four
Dopamine
Noreponphrine
Serotionin
Acetylcholine
What are the two main sources of dopamine in the brain stem? Where does it project to?
Ventral tegmental area project to Prefrontal cortex
Substantia nigra projects to caudate nucleus and putamen (stratium)
The two primary neural circuits from the striatum:
__________ faciliates movements
__________ inhibits movements
Direct pathways
Indirect pathway
Define
GPe
STN
GPi
SNr
SNc
GPe = globus pallidus external segement
STN = subthalamic nucleus
GPi = hlobus pallidus internal segment
SNr = substantia nigra pars reticulata
SNc = substantia nigra pars compacta
provides dopamine input to sriatum
What kind of dopamine receptors does the direct and indirect pathway have?
Direct pathways: D1 dopamine receptors (excitatory effect)
Indirect pathways: D2 dopamine receptors (inhibitory effect)
Parkinson leads to cell death that is most servere in _____________________-reduces neuromodulation of the striatum .
dopamine neurons of the SNc
What are the signs and symptoms of Parkinson’s disease?
Motor movements
Bradykinesia, slowness of movement
Resting tremor (shaking during periods of inactivity)
Muscle rigidity (resistance to imposed movements)
Non-motor symptoms
sleep disorder, disturbances of autonomic N.S. function, mood changes, and cognitive impairment
Signs
age-dependent, great prevalence at older ages
worsening over time
In cases where Parkinson disease is thought to be inherited –> _____________. Prevalence among close relatives, more likely to have an earlier onset. Some (but not all) cases have a known cause that is monogenic (based on a single gene).
Otherwise, no clear evidence of being inherited is known as ___________. Most cases of Parkinson’s disease.
Familial
Sporadic
True or False
The likelihood of Parkinson’s disease depends on genetic and environmental risk factors.
Multiple factors interact to increase and decrease the risk of Parkinson’s disease.
True
