6 - Overview of the signalling pathways in the CNS Flashcards
What is the difference between inter and intra-cellular signalling?
inter-cellular = "between cell" intra-cellular = "inside cell"
What are the most abundant excitatory and inhibitory neurotransmitters in the hypothalamus?
And what type of neurones are they transmitted by?
Excitatory = Glutamate - Spiny neurones Inhibitory = GABA - Non-spiny neurones
Forms of inter-cellular signalling: Give 1 example of:
Direct cell to cell contact
Secreted ligands
Synaptic transmission
Direct - Adhesion molecules, electric fields
Secreted - Neurotransmitters, netrins, trophic factor
Synaptic - Neurotransmitters
What are the 2 major classes of synapses?
Electrical synapses
Chemical synapses
What are the most common
a) Excitatory synapses
b) Inhibitory synapses
Glutamatergic
GABAergic
What is the structural difference between Glutamate and GABA
They both have a 3 carbon chain with COOH and NH2 terminals, but
Glutamate has an extra COOH because it’s an amino acid.
Which types of receptors regulate ion channels?
Give some examples.
Ionotripic
GluR, GABAR, ATPR
Which types of receptors regulate the metabolism?
Give an example
a) in the membrane
b) inside the cell
Metabotropic
Membrane = G protein linked, enzyme linked
Cell = guanylyl cyclase, hormone receptors
Draw the allosteric NMDA receptor
include antagonists, modulatory cites, receptor site and any other features
Lecture slide
Includes, Glutamate +, MG2+ -, Channel blocking drugs, Na+, Ca2+, Glycine, Polyamines
Draw the allosteric GABAa receptor
include antagonists, modulatory cite, receptor site and any other features
Lecture slide
Includes: GABA +, Cl-, Channel blocking drugs, Benzodiazepine agonists, antagonists, benzodiazepine inverse agonists, channel modulators.
Give some an example of a
a) Voltage gated ion channel
b) Transmitter-gated ion channel
c) Transmitter+voltage gated ion channel
a) Calcium/sodium/potassium channels
b) AMPAR/ cholinergic nicotinic etc.
c) NMDAR
Give some a) extracellular b) intracellular sources of calcium
Extracellular = NMDAR and vdCC Intracellular = RyR, IP3R
What are some functions mediated by G-protein linked receptors at the intra and extracellular level? (5)
Neurotransmission Cell growth and differentiation Reorganisation of cytoskeleton Intracellular transport exo and endocytosis
What are the two kinds of G-proteins?
1) Hetero G-proteins
2) Small G-proteins
Small G proteins are a superfamily of ____ proteins.
They are regulators of _____ transduction, leading to organisation of ______ and _______.
Small G proteins are a superfamily of switchproteins.
They are regulators of signal transduction, leading to organisation of the cytoskeleton and cellular traffic.
What are some of the members (and their functions) of the small G protein family? (5)
Ras - cell proliferation and differentiation
Rabs - directionality of transport
Arfs - vesicular trafficing, activation of phospholipase B
Rhos/Racs - regulation of cytoskeleton
Rans - regulation of nucleocytoplasmic transport of RNA and proteins during the G1, S, and G2 phases of the cell cycle and microtubule organization during the M phase.
What is the function of the Rans G protein?
Regulation of nucleocytoplasmic transport of RNA and proteins during the G1, S, and G2 phases of the cell cycle and microtubule organization during the M phase.
What are some benefits, and 1 drawback of the G-protein system?
Benefits:
Amplification of signal, great environment for regulation, long lasting, highly conserved.
Drawback: Slower than other signalling systems
Draw the EGF transduction pathway (example of metabotropic action with use of small G-protein)
lecture slide
EGF receptor, tyrosine kinase domain, Grb-2 adapter protein, SoS (guanine nucleotide exchange factor), GDP-GTP(ras->activated Ras)
