Lecture 3

?
  • Created by: The Shrew
  • Created on: 20-02-16 12:21
Temporal summation
Several impulses from one neurone over time before neurone reaches baseline- reaches threshold, can be hyperpolarising as well (anaesthetics)
1 of 53
Spatial summation
Impulses from several places to one neurone
2 of 53
Many neurones don't have AP or they're very short
Conduction is passive or decremental
3 of 53
Based on squid motor neurone
Not all like this- can fire automatically even when no input, don't display AP, dendrites can activity transmit AP
4 of 53
Mylinated axons/ Non mylinated
224mph (cats)/ 2.24mph
5 of 53
Can't all be mylinated
Too thick, only essential things (quick pain= mylinated/ long term ache= non-mylinated)
6 of 53
Electrical synapse
Bidirectional- some plasticity
7 of 53
Fast
0.2ms from neurone to neurone/ connect large group of neurones/ Evolution
8 of 53
Controls brain as a whole
Keeps between coma and seizure
9 of 53
Cerebral cortex
Allow network of inhibitory neurones to fire in a highly coordinated way
10 of 53
Chemical
2ms from neurone to neurone/ can only go one way- two sides different
11 of 53
Directed synapse
Site of NT release and receptor are in close proximity
12 of 53
Non-directed synapse
Distance between release and receptor- can go several places at the end of an axon
13 of 53
Depolarization of pre-synaptic membrane
Ca2+ goes in through voltage gates- facilitated diffusion
14 of 53
NT produce signals by
binding to receptors (proteins) that are specific for given NT
15 of 53
Ligand
Molecule that binds to another
16 of 53
Multiple receptor subtypes
for one given NT
17 of 53
2 biochemical features that receptors have in common
Membrane spanning proteins/ region exposed to external environment recognises and binds transmitters
18 of 53
Ion channels/ ligand gated channels/ Ionotropic receptors
Need key to open/ excititary or inhibitory
19 of 53
Excitatory Ionotropic receptors
NT binds to ionotropic receptor, associated channel opens or closes inducing immediate post-synaptic potential
20 of 53
Inhibitory
Can let K+ out (with conc gradient but not polar gradient) or let Cl- in- Inside of cell more negative
21 of 53
Alcohol
binds to GABA receptors and makes them stay open- more Cl- in cell= inhibited in cerebellum which messes up balance and speech
22 of 53
G protein linked/ Metabotropic
key changes inside of membrane slightly- wave of positivity/ excitatory or inhibitory
23 of 53
Slower to develop but
longer lasting, more diffusion and more variables/ some in presynaptic receptors and autoreceptors
24 of 53
Autoreceptors
Don't control ion channels/ always metabotropic/ bind to neurones own neurotransmitter/ located in presynaptic membrane/ control internal processes- synthesis and release of NT
25 of 53
Neurotransmitters (5 assumptions)
Produced within a neurone/ Released when neurone is stimulated/ Acts on post-synaptic receptor and causes biological effect/ must be inactivated once released/ chemical is applied on post-synaptic membrane
26 of 53
4 small molecule NT
Amino acids, Monoamines, Acetylcholine, Unconventional Small-NT
27 of 53
Amino acids
Molecular building blocks of proteins
28 of 53
Obtained through
Proteins we eat or protein synthesis
29 of 53
Found at
Fast acting direct synapses
30 of 53
Most prevelent excitatory NT
Glutamate
31 of 53
Most prevalent inhibitory NT
GABA
32 of 53
Monoamine synthesized from
single amino acid
33 of 53
Synpases tend to be
Non-direct= effects are variable
34 of 53
Acetylcholine synthesised by
Adding an acetyl group to chlorine
35 of 53
Synpases
Fast acting/ direct
36 of 53
Two types of receptors distributed differently in nervous system
Nicotinic (ionotropic, activates muscles)/ Muscarinic (metabotropic, memory)
37 of 53
Unconventional small NT
Soluble gases= exist only briefly/ easily pass through cell membranes/ involved in retrograde transmission (regulate activity of presynaptic cells)
38 of 53
Endocannabinoids
Similar to THC/ inhibit release of NT
39 of 53
Neuropeptides
Large- need nucleus/ 100 identified/ more and more being discovered/
40 of 53
Released at
Non-direct synapses
41 of 53
Neurotransmitter Pharmacology
Agonist- facilitate activity/ Antagonist- inhibit activity
42 of 53
Termination of NT action
Receptors need a rest or they stop responding, exposure must be limited
43 of 53
Diffusion
let NT diffuse away- not quick enough
44 of 53
Enzymatic breakdown
Enzyme breaks down NT and recycles
45 of 53
Reuptake
Protein in presynaptic neurone brings it back in and recycles- prozac stops this from happening with dopamine
46 of 53
Glial uptake
Glia wraps around terminal and reuptakes and recycles
47 of 53
Neuromodulators
Aid release of NT/ inhibit reabsorbsion of NT/ delay NT breakdown/ determines mental state- moods long lasting
48 of 53
Released at
non-direct synapses
49 of 53
Colocalization/ Coexistence
Many neurones contain more than one NT (usually one small and one neuropeptide)
50 of 53
Axoaxonic synapse
axon of a neurone synapses with the presynaptic terminal of another
51 of 53
Presynpatic inhibition
Reduction in amount of NT released, lessen voltage sensitivity of Ca2+ channels/ Open Cl- channels on postsynaptic terminal (don't feel pain under stress- evolution)
52 of 53
Presynaptic facilitation
Classical conditioning- increases Ca2+ entry on postsynaptic terminal
53 of 53

Other cards in this set

Card 2

Front

Spatial summation

Back

Impulses from several places to one neurone

Card 3

Front

Many neurones don't have AP or they're very short

Back

Preview of the front of card 3

Card 4

Front

Based on squid motor neurone

Back

Preview of the front of card 4

Card 5

Front

Mylinated axons/ Non mylinated

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Psychology resources:

See all Psychology resources »See all Biological psychology resources »