THE BRAIN and how cocaine affects it

1
THE BRAINand how cocaine affects it!!

• Biochemistry

BY Ellie, Emily, Emma, Candy, Hayley and Jemma
2
What is a Neuron??
A neuron is a cell specialised to conduct
electrochemical impulses, called nerve impulses
or action potentials.

• We will look at
• Sensory Neurons
• Motor Neurons
• Multipolar Neurons

3
Sensory Neurons

• Sensory neurons transmit impulses to the spinal
  cord and brain from all over the body.
• Sensory neurons run from the various types of
  stimulus receptors, such as
• Touch
• Odour
• Taste
• Sound
• And Vision

4
Motor Neurons
Motor neurons carry impulses away from the
spinal cord and brain, to the muscles. Most
motor neurons are stimulated by interneuron's,
although some are stimulated directly by the
sensory neurons. Interneurons neurons that
connect directly to other neurons.
5
Multipolar Neurons
A Multipolar neuron usually has one very long
axon and many dendrites, this allows integration
of a great deal of information from other
neurons. Multipolar neurons are the majority of
neurons in the brain.
6
How Neurons are similar to other cells in the body

• Neurons
• Are surrounded by a cell membrane
• Have a nucleus
• Contain cytoplasm, mitochondria and other
  organelles
• Carry out basic cellular processes like protein
  synthesis and energy production

7
How neurons are different to other cells in the
body

• Neurons
• Have dendrites and axons
• Communicate with each other through an
  electrochemical process
• Contain specialised structures (synapses) and
  chemicals (neurotransmitters).

8
ACTIVITY

• Pin the label on the neuron.

9
Action potential

• Sodium ions diffuse into the neuron through ion
  channels.
• The neuron becomes depolarised.
• The Inside of the axon becomes positively
  charged.
• Potassium ions diffuse out of the neuron.

• The action potential in a neuron is the nerve
  impulse, which is like a wave of voltage that
  travels along the membrane of the axon of a
  neuron.

10
An action potential at one patch of the neuron
raises the voltage at nearby patches,
depolarizing them and provoking a new action
potential there. This carries on down the neuron
and is how the action potential moves along a
neuron.
The axons of neurons generally branch, the
action potential stops at the end of the branches
and causes the secretion of neurotransmitters at
the synapses that are found there.
11
After the resting potential has been restored,
sodium-potassium pumps move sodium ions out of
the neuron and move potassium ions out of the
neuron by active transport.
12
Active Transport
Active transport is an energy based process where
particles are moved across a cell membrane.
Active transport is used When a particle is
moved from a low to a high concentration. When
selectively impermeable particles need help
entering the membrane.
http//www.dnatube.com/view_video2.php?viewkey2e2
7e13572cbf59eb343
13
Synapse

• Specialised junctions between neurons.
• Connects nervous system together
• Converts electrical impulses into chemical
  signals.
• Impulses that travel down the neurone stimulate
  the release of neurotransmitters which bind to
  receptors of neighbouring neurone (signal)
• This happens across the synapse due to action
  potential

14
What is cocaine?

• Where does it come from?
• How do you purify it?

15
Chemically what is it?

• benzoylmethyl ecgonine
• A crystalline tropane alkaloid
• Tropane tells you its a nitrogenous bicyclic
  (double ringed) organic compound
• And Alkaloid tells you it contains naturally
  occurring chemical compounds containing basic
  nitrogen atoms

16
So where does it come from and why is it called
cocaine?

• Its taken from the leaves of the coca plant
  hence Coca
• And the suffix of alkaloid compounds ine hence
  Cocaine

17
How do you purify cocaine?

• Impure cocaine is in the form cocaine
  hydrochloride this can be purified to form
  freebase cocaine
• Firstly the cocaine hydrochloride is dissolved in
  water.

18

• Once dissolved, cocaine hydrochloride (Coc-HCl)
  dissociates (separates out) into the protonated
  cocaine ion (Coc-H) and the chloride ion (Cl-)
• Any solids that remain suspended in the solution
  are impurities from the cut and can be removed by
  filtration.

19

• A base, typically ammonia (NH3), is added to the
  solution, the following net acid-base reaction
  takes place
• Coc-H(aq) NH3(aq) ? Coc(aq) NH4(aq)
• As freebase cocaine (Coc) is insoluble in water,
  it precipitates and the solution becomes cloudy

20
So how do you separate your free base cocaine
from the solution?

• Add diethyl ether to the solution.
• Since freebase is highly soluble in ether, a
  vigorous shaking of the mixture results in the
  freebase being dissolved in the ether.
• As ether is practically insoluble in water, it
  can then be siphoned off.

21
What is a siphon?

• A siphon is a continuous tube that allows liquid
  to drain from a container via an intermediate
  point higher than the container.
• The flow is driven only by the difference in
  hydrostatic pressure (so no need for pumping).

22
Finally

• The ether is then left to evaporate, leaving
  behind the nearly pure freebase.
• But there are problems

23
And now for some fire!

• Handling diethyl ether is dangerous because ether
  is extremely flammable
• Its vapors are heavier than air and can creep
  from an open bottle
• Also in the presence of oxygen it can form
  peroxides, which can spontaneously combust.

24

• So dont go trying to smoke freebase cocaine
  whilst its wet with ether unless you want to
  cause an explosion and set yourself on fire!

25
Cocaine!
26
Effects Of Taking Cocaine

• Taking cocaine makes users feel on top of the
  world. People taking it also feel wide-awake and
  confident.
• Short-term effects of taking cocaine are
  increased energy, decreased appetite, and
  increased heart rate and blood pressure.
• Long-term effects include addiction, paranoia,
  irritability, restlessness, auditory
  hallucinations, mood disturbances.

27
How does Cocaine effect the brain?
28
What is Dopamine?

• Dopamine is a neurotransmitter that is released
  by cells of the nervous system during rewards
  such as eating food or having sex that give us
  pleasurable feelings.

29

• Dopamine is stored in vesicles
• Electrical impulse travels down neurone
• Activates the release of Dopamine
• Travels across synapse
• Binds with receptors on next neurone
• Sends signals
• Protein Dopamine transporter absorbs the
  Dopamine up to storage vesicles

30
How does Dopamine lead to Cocaine highs?

• Cocaine binds tightly to the dopamine transporter
  protein,
• Forms a complex which blocks its function.
• Causes a build up of dopamine in the synaptic
  cleft
• This excess dopamine is what causes the Cocaine
  high

31
(No Transcript)
32
Can Cocaine Cause Brain
Damage And Depression?
EVIDENCE

• Scientists from Edinburgh University have warned
  that taking cocaine could cause irreversible
  brain damage.
• A study by researchers from the University of
  Michigan suggests that chronic cocaine use may
  cause damage to brain cells that help to produce
  feelings of pleasure.

33
Can Cocaine Cause Brain Damage And
Depression?
SCIENTIFIC EXPLANATION

• The abnormally long presence of dopamine in the
  brain is responsible for the pleasure effects
  associated to the use of cocaine.
• Low levels of dopamine causes depression,
  fatigue and altered moods.
• Sometimes during the cocaine high, the brain
  shuts down neurotransmitters permanently.

34
(No Transcript)
35
BINGO!!

• Cocaine
• Synapse
• Neurone
• Active Transport
• Action potential
• Axons
• Receptors

Dendrites Siphon Diethyl ether Dopamine
transporter Neurotransmitter