Flash Cards
I =
Q/t
Paper on patch clamp configurations.
Sakmann and Neher (1984)
V =
IR
G =
1/R
G adds up in parallel circuit
Q =
CV
AND
It
Capacitance =
εA / d
AND
Q/V
Time constant, τ =
RC
τ is in s
It is the time required to charge a capacitor through the resistor by ~63.2% (1- e^-1) of the difference between initial and final value.
Total current, Itotal
NiP
Properties of AP
1) Threshold
2) All or none law
3) Frequency Coding
Nernst Equation
(RT/Fz)ln([X]out/[X]in)
R = 8.314 J/Mol K F = 96500 c/mol
Paper on intracellular recordings`
Hodgkin and Huxely, 1939
Paper on Shaker K+ channel inactivation
Hoshi et al., 1990`
Membrane length constant
λ = √rm/ra
AND
λ = √(dxRm)/(4.Ra)
Paper on discovery on Na and K voltage gated currents
Hodgkin and Huxley 1952
Conduction on specific ion
gna = Ina / (Vm - Ena)
for sodium
Paper on conductance of membrane to ions increase during AP
Cole and Curtis, 1938
Specific membrane resistance, Ra
L/(πr^2)
Membrane Capacitance, Cm
(ε x εo x 2πrL) / d
Paper on spatial buffering via glial cells
Newman, 1984
Calcium concentrations
Ex = 1-2mM In = 50-100nM - when active = 500-1000nM
(Berridge et al., 2000)
Paper on GABA transporters
Guastella et al., 1990)
Number of quanta released, m
m = np
AND
m = ln(total trials/failures)
Probability of release, Px
binomial release
n! / (n-x)! x!
Poisson Distribution, Px
Px = (m^x . e^-m) / x!
Probability of release of specific vesicle, p(x)
p(x) = [ N! / (N-x)! x! ] . P^x (1-P)^N-x
Mean amplitude, I (with binomial distribution)
I = NPQ
Variance of current, σi
σ^2 = QI - (I^2/N)
Paper on additive effect of GABAB and 5HT activation
Andrade et al., 1986
Lüscher et al., 1997
Paper on mice lacking GIRK2 K+ channels showing no response to GABAB agonists - betagamma complex opens K+ channels causing hyperpolarisation
Takahashi at al., 1998
GABA B presynapticallt reduces EPSC in medial nucleus of trapezium body (MNTB) - inhibits VGCC via betagamma complex
Paper on long term potentiation mechanism
Giese et al., 1998
Paper on caged calcium
Ellis-Davies, 2007
Paper on caged glutamate
Sheperd and Huganir, 2007
Charge of one electron
1.6x10^-19 coloumbs
One coloumb
6.25x10^18 electrons
K+ ion channel paper
Levitan and Kaczmarek, 1997
Na/K ATP-ase
2 alpha/2 beta subunits (only alpha involved in pumping)
Na/Ca exchanger
3 Na+ enter for each Ca2+ leaving
IP3 receptors
Optimal response at 300mM Ca conc - biphasic regulation
On ER membrane, 4 subunits, inhibited by heparin
Ca2+ off mechanism
Ca2+ buffers
Re-uptake into ER via SERCA and mito via uniporter or NCX
Extrusion by PMCA or NCX on plasma membrane
SERCA
Transports 2 Ca2+ per ATP, high density on ER membrane, active at high [Ca2+]cyt and inhibited at high [Ca2+]er
PMCA
1 Ca2+ out per ATP and 2 H+ in
10 transmembrane regions
Autoinhibitory deomain with CaM binding site - activated by Ca-Cam
Regulated by PKA/C phosphorylation
Synaptic fusion
Ca sensor synaptotagmin1 detects Ca and initiates Munc13-dependent priming of fusion machinery
v-SNAREs, synaptobrevin bind to t-SNAREs, SNAP-25 and syntaxin.
SNAREs form tight helices - one from v-SNAREs and 3 from t-SNAREs.
Vesicles released within 100us of AP arrival
Limitations of ChR2
Desensitisation - reduced membrane depolarisation at later pulse, depolarisation block - does not allow repetitive stimuli
No sufficient repolarisation between pulses
Reduced expression level or conductance
Slow channel inactivation (slow kinetics)
Paper on protein phosphatases and LTD
Bear et al., 1995
Paper on endocannabinoid retrograde signalling and LTD
Smart et al., 2008
Paper on gene deletion of alpha subunit of CamKII
Silva et al., 1992
Paper on NMDA antagonist AP5
Collingridge et al., 1983
Paper on D-serine released by astrocytes reducing LTD in hippocampus
Achour et al., 2010
Paper on NMDA knockout using Cre/LoxP recombination system
Tsien et al., 1996
Chen et al. 2003
Paper on PPF/D hippocampal cells single synapses.
Quanta visualised using FM 1-43 dye.
PPF no change in quantal size - increased prob of release
PPD decrease in quantal size and decreased prob of release
LOmo and Bliss 1973
First described LTP in perforant pathway and dentate gyrus in anaesthetised rabbits.
They showed that a burst of tetanic (100Hz) stimulus on perforant path fibres led to dramatic and long-lasting augmentation in post-synaptic response of cells.
Orkand et al., 1966
Intracellular recordings from glial cell in optic nerve of mudpuppy (necturus). Showed that nerve activity can depolarise glial cells.
Porter and McCarthy, 1998
Transgenic mice lacking astrocytic glutamate transporter GLT-1 develop epilsepsy and increased susceptibility towards convulsants
Paper on glial cells exporting glutamate upon depolarisation by influx of K+ (from ischaemia), Na+, or glutamate or increased extracellular pH (H+)
Billups and Attwell, 1996
Electrogenic glutamate transport was studied in whole-cell clamped glial (Muller) cells isolated from salmander retina
Berridge et al., 1993
Ca binds to IP3 receptors to release Ca from ER (CICR)
