A summary of semester 1 year 2 neuroscience lectures. Covers a brief overview of year 1 action potentials, basic neuroanatomy, neurohistology and development of the nervous system from the neural plate.
µ④IM
Neuroscience is an
integrative discipline
-
includes behavioural aspects as well as generic Topics to be studied -
neuroanatomy
-
molecular neuroscience -
brain development ,
construction of neural circuits molecular
,
aspects of synaptic unction
Systems neuroscience
sensory systems ( pain
-
touch ,
hearings motor
systems
-
. ,
i: ÷÷÷÷¥:÷:÷
First Year Topic -
divisions of the nervous system Motor = efferent, visceral and somatic
Visceral = sympathetic, parasympathetic, enteric
-
1st
Year Topic -
neurons
f.
nown
Ramon Y
•
neuro anatomist
Dyes
Cajal
in
"
show connections
FEEL www.giia.eu
IN PNS -
Schwann cells t
sat elite cells
↳
{
First Year Topic
-
-
ionic basis of the action potential
started the field op
-
neuroanatomy
-
Drew
diagrams of how cats connect
•
By adding selective channels, a diffusion potential is
generated -
causes difference in cone across membrane
model systems electrochemical gradient
• C.
elegans used for molecular
-
manipulation,
• Concentration gradient t
Fruit fly ( Drosophila) the relationship between the
•
•
Equilibrium potential -
•
Locusts electrochemical gradient + the development of a
potential difference
• Mouse -
Used for mammalian studies
First Year Topic First Year Topic synaptic -
transmission
-
nernst equation
Action potential arrives at
synapse
-
Has constant a
t
Ift
T temperature IN
E,
-
=
loge 1kt ] in
i. valence or .
ion
nerve terminal depolarises
f :
faraday constant
( it forth )
not
change
Voltage
" "
Ca channels open Ca
,
gated
0
simplifies
-
to
in
Em V. 61.51g ,oEH 0 Vesicles bind to the membrane
migrate
t
µ, in
•
Used to calculate the electrical 0 Neurotransmitters are released into the
synapse
potential of a chemical reaction 0 NTS bind to
receptors on
postsynaptic neuron
•
shows direct relation between
energy or a con and its
participating
°
Postsynaptic potentials svmmate until membrane
ions reaches the threshold for an action potential
, NN11 BASIS OF THE RESTING MEMBRANE POTENTIAL AND THE
ACTION POTENTIAL Inside of membrane is more -ve
than outside
Properties of neurones Giant squid AK0N Used amplified voltmeter
Excitability °
o The first detailed studies on
excitability
-
in 40 's 150 's
°
Integration filtering +
propagation of
signals generation of an output Giant tractable atoms are accessible for experimentation
-
o
,
Transmission of Electrode inserted inside axon and one outside .
signals
° o
calculated volt
potential difference using an
amplified
Plasticity Change in the ways they behave tacitability
° -
meter
0 Found the inside the axon is respect
of negative with
-
HOW is membrane potential generated ? to the outside
Difference in between the inside
What happens
• ion concentration +
the outside of the atom
when
permeability changes ?
when
eg an ion channel is
opened
-
.
Nat/I5m#
10N INSIDE OUTSIDE
° Nat wants to into the cell down its cont
move -
h gradient ( electrochemical ) Excitatory
electrical -
Chi 4- 30mm 110mm ( Depolarisation )
0kt concentration gradient means it wants to move out
0 Selective permeability Of the membrane to kt Na+ in Cell but its
of the
electrical gradient means it wants to remain
o 10h pumps maintain gradients eg Nat Iht ATPase -
.
-
K+ out inside the
out
cell -
electrochemical
gradient cures it to move
Inhibitory (
Hyperpolarisation)
-
Electro
genie blocked by ouabain the nernst
equation
-
tells us that the overall movement
-
Of the Kt ions is out of the
(Eu is negative)
cell
-
Machines can be used to control membrane potential
Equilibrium potential ,
E ( Nernst equation) the electrical
charge experimentally t reverse the flow of ions
charged
-
""""
on one
they can decrease the internal membrane potential
:[
"""
loge Iout %msp%nII ftp.byjhgniygitcmgenegaiue.cauingntnmoueint
E-
II [ION 'T in
z -
valence of ion
+ -
faraday constant Ionic basis of the action potential
° Used to the two ( electrical concentration )
compare gradients t
← potassium current
starts to take over
°
determines the direction of iron movement at
given
membrane potential
any we feedback
loop
• converts chemical gradient to an electrical gradient I
rapid depolarisation -
caused
by polarisation
Simplified :
rapid activation of
Nat channels
voltage-gated [
EmV= 61.5 log ,
LIONI out
[ IONI in
(at 374 for mammalian
neurones)
excitatory
resting potential
event
my
µ
15 membrane
potential set only by permeability to kt ? -
no
-
Predicted slope on membrane potential -
[ KT1 out graph would be
a
straight line -
58mV per tenfold
change in [htt
Actual empirical values from experiments produce
In depolarisation -
Vm approaches Ewa the
spine is due to
-
a curve shows that
-
.
Ct ions are also
Nat t
important a transient increase in Pna
In re polarisation -
Vm approaches EK the spine is due
.
to a
transient increase in PK
Goldman Constant Field Equation
Em =
61.5 log '
PKLK t PNatnattotpcllcl.li
pkfnttitPNAINai.li TP4 4DO
Hodgkin that ,
1948
aimed to find out if action potential was
totally sodium dependant
-
-
managed to eradicate the action potential by removing eternal Nations
-
inward movement of Nat is the basis of an AP
-
the membrane is impermeable to Nat at rest
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller rebekahward. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £3.49. You're not tied to anything after your purchase.
