neuro physiology 1 Flashcards
resting potential is
- 70mV
depolarisation is ____mV
- 40mV
hyperpolarisation is ___mV
- 80mV
inside of cell is usually ___ charged in comparison to outside
negatively
which ions are abundant inside cell
K+
which ions are abundant outside of cell
Cl-
Na+
which 4 ions play a role in membrane potentials
Ca2+
Cl -
Na+
K+
sodium channels (na+) flows __, causing ___this acts in a ____ manner
inwards, depolarisation, excitatory
K+ channels flow __, causing ___this acts in a ____ manner
outwards, hyperpolarisation, inhibitory
Ca2+ channels flow __, causing ___this acts in a ____ manner
inwards, depolarisation, excitatory
Cl- channels flow __, causing ___ this acts in a ____ manner
inwards, hyperpolarisation, inhibitory
which ions move inwards during depolarisation
Na, Ca2, Cl-
which ions move outwards during depolarisation
K+ only
which ions are inhibitory
K+ and Cl-
which ions are excitatory
Na and Ca2+
Na+ channel agonists do what
open Na channels, Na influx leading to excitation
Na+ channel anatgonist do what
block Na channels, stops influx, favours inhibition
example of Na+ antagonist
lidocaine (anaesthetic)
K channel agonists do what
K channels open > K moves out cell > cell becomes more negative therefore inhibitory
K channel antagonist s do wha
keep K channels closed > keeps cell negatively charged > therefore excitatory
events leading to depolarisation
action potential depolarises axon terminal > Ca2+ channels open > Ca2+ flows into cell > Ca2+ causes exocytosis of neurotransmitter from vesicles > neurotransmitter diffuses and binds to post synaptic receptors
3 ways neurotransmitter is inactivated
- taken up by glial cells/ taken back up and re-used
- diffuses away
- degraded by enzyme
Neurotransmitters may act directly or indirectly on ion channels - direct is via ____ receptors
IONOTROPIC RECEPTORS.
Neurotransmitters may act directly or indirectly on ion channels - indirect is via ____ receptors
METABOTROPIC RECEPTORS
example of a metabotropic receptor is
muscarinic ACh receptor (G-protein complex)
example of a ionotropic receptor is
nicotinic (direct channel)
2 major families of ligand gated channels
1) GABAa, Glycine and ACh (nicotinic) receptors
2) glutamate receptors
GABAA, Glycine and ACh (nicotinic) receptors are what structure
pentamere
glutamte receptors are what structure
tetramere
what is the major excitatory neurotransmitter
glutamate
Glutamate: the major excitatory neurotransmitter, acts on ____ receptors to allow __ and __ in and _ out of the cell, net result is an ___, ___, and ____
ionotrophic
allows Na and Ca in
K out
EPSP
GABA: the major inhibitory neurotransmitter, acts on ___ receptors to allow __ into the cell, net result is an ___, ___, and ___
ionotrophic receptors
CL into cell
IPSP, hyperpolarization, inhibition
Interneurone: a locally-acting neurone, typically releases ___ and so brings about an ___ and ___, function is local processing of information
releases GABA
causes IPSP, inhibition
IPSP
EPSP
inhibitory postsynaptic potential
excitatory “ “
Projection neuron: a neuron responsible for conveying signals to other parts of the brain, typically releases ___ and so brings about an ____
glutamate causing EPSP
Excitatory neuron: releases a _____ neurotransmitter (e.g. ____)
depolarizing eg: glutamate
Inhibitory neuron: releases a ___ neurotransmitter (e.g. ___ )
hyperpolarizing eg: GABA
when is glutamate inhibitory
if response is at Metabotropic Glutamate receptors
