bioelectric communication between neurons

Ana Margarida Araújo

Ana Rita Oliveira

Felicia Negru

Filipa Leal

Luís Rita

Professora Ana Sebastião 1

Nervous Impulse Transmission

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4

5

Synapse

Electric

Chemical

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Chemical Synapses

Action Potential is transmitted by

special proteins called

neurotransmitters.

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Neurotransmitters Releasing

Neurotransmitters get out from the

pre synaptic cell by exocytosis.

After that they get in the synaptic

cleft.

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Receptor Molecules In Synapses

After that neurotransmitters

interact with the next cell. This way

the nervous impulse is transmitted

between 2 neurons.

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GABBA

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Glutamate

Inhibitory Responses Excitatory Responses

o Exocytose vesicles, spontaneously,

merge with the pre synaptic

membrane, propagating a nervous

impulse to the next neuron.

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o Substance that alters

nervous impulse

transmission.

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Adenosine

o It is a secreted protein

in humans.

o Encourage the growth

and differentiation of

new neurons.

o BDNF itself is

important for long-

term memory.

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o It plays an important role

in the consolidation of

information from short to

long-term memory.

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The goal of this experiment was to address weather BDNF

effects on mIPSC frequency are dependent on A2ARs

activation.

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Patch Clamp Method

Loose Patch

Cell Atatched

Whole Cell

Outside Out

Patch

Inside Out Patch

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o Removal of the

brain

o Dissection of the

hippocampus

o Acute brain slices

technique

o 300µm slices

o 2 to 4 weeks old

o Anesthetization

o Decapitation

Vibratom Hipppocampal Slice

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Visibility in

different

plans

Triangularly shaped

Not too bright

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Videos youtube

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http://www.youtube.com/watch?v=xwqFdL_ndMo http://www.youtube.com/watch?v=5ZgiacYwkyY

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Whole Cell Patch Clamp 24

Miniature events of the inhibitory response

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Adenosine A2A receptor agonist

Adenosine Activates Track B

receptors Potentiates

Effects of BDNF

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10 minutes of control time - with TTX, KYN, and SCH

40 minutes of data registration of the inhibitory response

10 min || 40 min

TTX, KYN,

SCH (100 nM)

BDNF 10

(ng/mL)

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Inverted Light Microscope

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Faraday´s Cage

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Air Table

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Micromanipulator

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Recording Electrode

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0 20 40

0

50

100

150

Time (min)

mIP

SC

fre

qu

en

cy

(% b

ase

line

)

BDNF 10 ng/mL

SCH 100 nM

0 20 40

0

50

100

150

Time (min)

mIP

SC

am

plit

ud

e

(% b

ase

line

)

BDNF 10 ng/mL

SCH 100 nM

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o Adition of SCH prevents the effects of BDNF;

o Results from a single experimente;

o Plenty of room for Biomedical Engeneering to

improve essencial equipement.

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1. http://www.bem.fi/book/04/04x/0427x.htm SLIDE 19

2. http://www.leicabiosystems.com/specimen-preparation/sectioning/vibrating-blade-

microtomes/details/product/leica-vt1000-a/ SLIDE 21

3. http://www.physiologie.uni-freiburg.de/research-techniques/electrophysiology

SLIDE 22

4. http://www.physiologie.uni-freiburg.de/research-techniques/electrophysiology

SLIDE 25