Neuro (Subject) / Prüfung MolMed (Lesson)

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• The main components of the CNS are ? brain (including retina) and spinal cord
• The 3 principle neuron types are? sensory neurons, interneurons and motor neurons (or structural classification: pseudounipolar, bipolar, multipolar)
• The main mechanisms that maintain the membran resting potential are? Na/K exchange pump
• The main differences between neuronal and non-neuronal cell nuclei are? neuronal nuclei have less heterochromatin
• EPSP and IPSP stand for? excitatory postsynaptic potential and inhibitory postsynaptic potential epsp/depolarization and ipsp/hyperpolarisation
• Properties of neural stemm cells: self-renewal differantiation to neural progenitors, neurons, astrocytes and oligodendrocytes
• Time-related processes in the embryo: Early: gastrulation, neural induction, neurulation, neurogenesis starts Late: gliogenesis, fetal and adult neurogenesis
• Some types of neurons originate from progenitors with far situated locations: (GABA)-eric cortical interneurons originate from the medial ganglionic eminence peripheral nuerons (sensory and autonomic) originate from the neural crest
• Adult neurogenesis takes place in the dentate gyrus of the hippocampus and  in the subependymal zone of the lateral ventricles
• Resistors connected in series ... Widerstände in Serie addieren sich; alle Teilwiderstände zusammen ergeben den Gesamtwiderstand; parallel geschaltete Kondensatoren verhalten sich wie in Serie geschaltete Widerstände; (Kanäle sind wie parallel geschaltete Widerstände)
• Which electronic components are required for an equivalent circuit of a real cell and which cellular components are equivalent to which electronic components? Widerstand/resistors => ion channels; Kondensator/capacitor => membrane; Batterie/battery => ion gradient; Stromquelle/current source => Na+/K+-ATPase; Diode/diode => rectifier ion channel
• The K+ equilibrium potential is calculated with the Nernst equation. Under which conditions can the calculated potential be realized in the neuron? Unter natürlichen Bedingungen nicht; Membran darf nur für dieses Ion durchlässig sein => es muss Kanäle dafür geben
• Which parameter(s) can be estimated from the cell’s capacitive current response to a voltage jump from 60mV in whole-cell mode? serial resistance (electrode R and access R) and membrane capactity
• Which of the patch-clamp configurations below allows investigation of single channels without changing cytosolic composition? Nur die cell-attached recording Technik
• What is true for a chemical synapses? - Distance pre-post-synaptic membrane: 20-50nm - Cytoplasmic continuity: no - Ultrastructural components: presynaptic vesicles and active zones; postsynaptic receptors - Agent of transmission: chemical transmitter - Synaptic delay: at least 0.3ms; usually 1-5ms or longer - Direction of transmission: unidirectional
• What is true for an electrical synapse? - Distance pre-post-synaptic membrane: 3-3.5nm - Cytoplasmic continuity: yes - Ultrastructural components: gap junctions (connexons) - Agent of transmission: ion current - Synaptic delay: virtually absent - Direction of transmission: usually bidirectional
• What are the properties of graded potentials? Inhibitory (IPSP) or excitatory postsynaptic potentials (EPSP) Brief, local changes in membrane potential, the larger the stimulus the greater the change in the membrane potential Can trigger an action potential at the axon hillock if their sum exceeds the action potential threshold (the potential becomes self-propagating) Different intensities; no threshold/refractory period; duration is dependent on initial stimulus; conduction decreases with distance (decremental conduction); single potentials summate; mediated by direct- or indirectly-gated ion channel opening via a receptor
• What is true for ionotropic receptors? => Directly-gated ion channels Fast, short-lasting synaptic response e.g. nACh, AMPA/NMDA, GABA(A) in CNS Neuromuscular junction in periphery
• What is true for metabotropic receptors? => G-protein coupled, indirectly-gated ion channels 2nd messenger cascade leading to indirect opening of ion channels Slower, long-lasting synaptic actions e.g. mACh, mGluR, GABA(B)
• Which proteins form the SNARE complex in the synapse? Synaptotagmin senses Ca2+ rise and triggers complex-building of synaptobrevin (also called vesicle-associated membrane protein, VAMP) and syntaxin (=SNARE complex) at the presynaptic membrane
• 3 synaptic proteins: vesicle-associated membrane protein (VAMP)/Synaptobrevin (v-SNARE)  Syntaxin [SNARE protein at plasma membrane]  SNAP-25 (t-SNARE) [SNARE protein at plasma membrane]
• Which of the following neurotransmitters is not recycled and needs de-novo synthesis? Proteinacous neurotransmitters are not recycled  classical NTs are recycled: - Glutamate - GABA - Glycin - Monoamines/Catecholamines: Dopamine (DA), Norepinephrine (NE), Serotonin (5-HT) , etc.
• What is the physiological intracellular Ca2+ concentration? 100nM
• Which is the rate-limiting enzyme in the acetylcholine biosynthesis? Cholin acetyltransferase [synthesizes acetylcholine from cholin and acetyl-CoA]
• Which of the glutamatergic receptors can conduct Ca2+ ions (in addtion to Na+/K+)? Ca2+ permeable AMPAR at excitatory synapses on GABAergic inhibitory interneurons --> GluA1, GluA3 and GluA4 have a Glutamine (G) --> NOT Ca2+ permeable --> GluA2 has an Arginine (R) instead of a Glutamine (G) --> Ca2+ permeable  [bin mir bei AMPAR nicht sicher!] Kainate receptor has variable Ca2+ permeability  NMDA receptor
• Which of these enzymes play a role in the synthesis and degradation of dopamine? tyrosine hydroxylase, L-aromatic amino acid decarboxylase, mitochondrial monaminoxidase (MAO) [degradation], catechol-O-methyltransferase (COMT) [degradation]
• Which of these enzymes play a role in the synthesis and degradation of seratonin? tryptophan hydroxylase, L-aromatic amino acid decarboxylase (=L-DOPA decarboxylase), MAO [degradation], aldehyde dehydrogenase [oxidation; also part of degradation]
• Which of these enzymes convertes dopamine in to noradrenalin/norepinephrine? dopamine-β-hydroxylase (DBH)
• Mark the main nucleus/nuclei of the dopaminergic system? Substantia nigra pars compacta (SNc), Ventral tegmental area (VTA), Arcuate nucleus
• Mark the main nucleus/nuclei of the noradrenegic system? Locus coeruleus (LC)
• Which of the following statements about myelination is correct? mostly postnatal; leads to increased brain volume; performed by oligodendrocytes (CNS) and Schwann cells (PNS); enables a very fast, saltatory AP propagation
• In two axons of the same diameter, a myelinated axon will conduct impulses faster than an unmyelinated one because? due to myelination, depolarisation occurs only at unmyelinated nodes of Ranvier -> very fast transmission of stimulus possible via saltatory AP propagation
• Cells found in the choroid plexus that secrete cerebrospinal fluid are: choroidal epithelial cells - ependymal cells (subtype of glia cells)
• Which technique/s can be used for brain neuroimaging? PET, MRI (and fMRI), SPECT
• To which of the next parameters is “greater drug selectivity” related to? Selectivity = if a drug binds only one particular receptor (therapeutic window) (can change at a certain concentration!) -> fewer potential side effects, more targeted approach
• What is an allosteric modulator for GABA-A? Benzodiazepines (e.g. Diazepam)
• For which indication were Selective Serotonin Reuptake Inhibitors developed? Depression
• Which of the following symptoms are part of the ICD-10 diagnosis „dependence syndrome“ (ICD-10 code F1-.2): · Strong desire or sense of compulsion to take the substance · Difficulties in controlling substance taking behavior in terms of its onset, termination or level of use · Withdrawal symptoms · Evidence of tolerance (increased doses needed to achieve effects) · Progressive neglect of alternative pleasure or intrests (craving for the drug is the center of the persons life) · Persisting with substance use despite clear evidence of harmful outcome
• Which of the following brain regions is NOT currently thought to be part of the so-called "reward circuit"? Involved brain regions: Nucleus accumbens, Ventral Tegmental Area (dopaminerge Neurone zum N. acc.), Hippocampus, Prefrontal cortex, Basolateral Amygdala
• Which of the following brain regions mediate both appetitive and aversive behavior, i.e., both ‚’attraction’ (‚reward’) and ‚aversion’? VTA (ventral tegmental area)
• Which of the following neuron types constitutes the majority of neurons in the medial nucleus accumbens core? Wikipedia: medium spiny neurons
• Which are crucial steps in the biosynthesis of neuropeptides? Start of biosynthesis= nucleus; trx mRNA codes for prepropeptide, signal peptide goes into ER. Packed in large dense core vesicles (transgolgi), cleavage of signal peptide by catabolic enzymes before synthesis is completed. Large dense core vesicles are not recharged, no recycling, but de novo synthesis!
• Which of the following statements about neuropeptides is true? Als Kotransmitter wirken sie als Neuromodulatoren, indem sie die Wirkung der Neurotransmitter modulieren, also unterstützen oder hemmen. Die Synthese und der Transport sind im Gegensatz zu niedermolekularen Botenstoffen eher langsam und träge. Die Neuropeptide werden an den Ribosomen im Perikaryon synthetisiert und nicht – wie bei niedermolekularen Botenstoffen – im Axon. Kotransmitter binden zudem nicht direkt an Ionenkanäle und verändern somit auch nicht die Spannung der postsynaptischen Membran, sondern wirken über Rezeptoren auf Zellfunktionen und auf die Zellstruktur der postsynaptischen Zielzelle.
• Which are main differences between neuropeptides and classical transmitters? NP: Characteristic of NP= Peptide bond, synthesis at ribosomes De novo synthesis G-protein coupled receptors
• Which hormons are also neurotransmitters? somatostatin, NPY
• Spatial orientation involves which specific cells? Hippocampal place cells , grid cells, Head direction cells
• Which neurotransmitters are involved in sleep control? ACh, GABA, Norepinephrine, Serotonin, Dopamine, Histamine, Hypocretin
• What is long-term potentiation? =high-frequency stimulation of neurons in the hippocampus results in lasting increase in synapse strenght; relies on NMDA receptors, if blocked=no learning. Depolarization of membrane promotes opening of NMDA: removal of Mg Ion and Ca influx; PKC-->AMPA activated, Phosphorylation of retrograde messengers
• What does the ‘Rheostat model’ by Korsmeyer explain? that the relative concentration of Bcl2/Bax family member interactions determines the apoptotic fate of a cell (e.g. high Bax concentrations -> Bcl-2 displaced from Apaf-1 -> activation of apoptotic pathway -> apoptosis)
• Which of the following is a pro-apoptotic member of the Bcl-2 family of proteins? Bax, BH3 family (Bim, Bad, Bid)

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