Flashcards in Lecture 4 Deck (50):
What is the target in the brain of abuse drugs?
The brain's pleasure centre
Brain reward (dopamine) pathways
These brain circuits are important for natural rewards such as food, music and sex - also associated with drug use
Typically dopamine increases in response to natural rewards such as food
When cocaine is taken, dopamine increase is exaggerated, and communication is altered - happy and lots of energy
For every affect with the drug, there are affects without the drug= e.g. stimulant makes you feels depressed when NOT using it
(action/reaction) (usually opposite)
What is Ecstasy?
A derivative of amphetamine (amphetamine is the parent drug)
Amphetamine type stimulant
Chemical structure similar to methamphetamine
What are other names for Ecstasy?
How does Ecstasy get into the brain?
15 minutes (empty stomach)
Reaches the brain Easily
1. Disintegrates in stomach
2. "E" absorbed into blood stream from stomach and small intestines
3. Travels to liver and then carried through veins and heart
4. Pumped form heart --> to lungs with blood which becomes oxygenated and returns to heart
5. Oxygenated blood carries "E" to brain and other organs
"feel good drug" = can lead to dependance - psychological and physiological dependance = does change the brain
What areas of the brain are affected by Ecstasy?
Limbic System stimulated:
"feel good perception"
systems associated with thinking and problem solving and making good decisions
What are the Acute Effects of Ecstasy?
Neocortex: Heightened Perceptions
Hypothalamus: Reduced appetite
Basal Ganglia: Stimulation
Amygdala + Hippocampus: Elevated Mood
What are the Adverse effects of Ecstasy?
Neocortex + Hippocampus = Clouded thinking
Hypothalamus = Hyperthermia
Amygdala= Disturbed behaviour
Neocortex = Jaw clenching
What damage does ecstasy have on brain areas controlling memory?
Neocortex= Memory impairment
Hippocampus = Memory impairment
What are the Serotonin Nerve Pathways in the Brain
Raphe Nucleus + through a number of regions
affect limbic system plus other systems associated with thinking and problem solving and making good decisions
What is the difference of Serotonin Neuron Junction with and without Ecstasy?
Stimulated and release serotonin into synaptic cleft
any that isn't attached to receptor is taking back into cell through a TRANSPORTER (the target of ecstasy)
transporters= stop serotonin being taken back into cell or increase amount in synapse, which makes neurons fire like crazy, makes you feel great
What are the Short Term effects after Ecstasy has gone?
Feelings of ecstasy extend/continuing affecting after it has left the body
During Ecstasy: Elevated mood
After Ecstasy: depression like feelings, irritability, clouding thinking
What are the life threatening effects of ecstasy?
death= due to "stacking" (overuse)
What are the Long term effects of Ecstasy?
1. Brain Chemistry changes:
a. Serotonin reduced
b. Serotonin metabolites reduced
2. Brain Structure changes:
a. Serotonin transporters reduced
b. Serotonin terminals degnerate
reduced function in the brain proven by cat scans of monkeys
How does the levels of Serotonin Present in the Cerebral Cortex Neurons change with ecstasy use?
Before: Normal levels of serotonin
2x weeks after Ecstasy: Severely diminished levels of serotonin
7x years after Ecstasy: still diminished levels of serotonin and still less than before Ecstasy use
What is a difference between past and current MDMA users in regards to Impulsivity?
Compared in Matching Familiar Figure Test(measuring response time)
Current and past MDMA users made Quicker decisions and More Wrong choices before identifying the correct match
What do we know about the short and long-term effects of Ecstasy on the brain?
Ecstasy has both Short-term and long-term effects on the brain
Short term: changes brain Chemistry and behaviour
Long term: changes brain Structure(fewer neurons) and behaviour and memory and ability to problem solve
What is the basic brain development?
Very sensitive period of essential brain development
1. Brains are built over time-
development begins well before birth and continues throughout early childhood
2. Biology of the brain is affect by - genes passed from parents to child - the environment of the womb - the experience the child has
What are the 3 thing the which affects the biology of the brain?
1. Genes passed from parents --> to child
2. The environment of the womb
3. The experiences a child has
What two questions to we want to know about drugs and the developing brain?
1. who does prenatal exposure to different drugs and alcohol affect the developing brain and ongoing development?
2. Which drugs are "Teratogens"?
What are Teratogens?
An environmental age that causes damage during the Prenatal period
Genetic makeup of the mother and developing organism may enable or hinder their ability to withstand harm
-have a differential affect
What does the Teratogenic effects of a drug depend on?
Dose of the Exposure (need a lot/continually use)
Timing of the Exposure and Conditions of the Exposure
How are the Effects of Teratogens dependant on the Timing of the Exposure
Most vulnerably during embryonic period when the most changes are going on - problem as most people don't figure out they are pregnant by that time and are already exposing the baby to drugs
Period of dividing zygote/implantation=weeks 1-2 = usually not susceptible to teratogens = prenatal death
Embryonic period = weeks 3-8 = major structural abnormalities
Metal Period/Full term = weeks 9-36 = Physiological Defects and Minor Structural Abnormalities = born pre-term also a risk
What is an example of a Teratogen?
Prescription and Non-prescription Drugs:
1. Thalidomide= Originally given to mother to avoid morning sickness + sedative
Causes birth defects, shortened/no limbs
2. Diethylstilbestrol (DES)
3. Aspirin = early infant death, decreased motor development
4. Heavy caffeine intake= premature, miscarriage
What are some examples of Stimulants?
How can Cocaine have a teratogenic affect on pre-natal babies?
Deformities of genital, urinary tract, kidney and heart
How can Methamphetamine have a teratogenic affect on pre-natal babies ?
Delayed motor development (over first 3 year- not walking as soon e.g.)
Affects males and Maori babies more
What are examples of Opiates?
Heroin/ MSTI/ Homebake
Methadone/Buprenoprhine- Withdrawl drugs- man made product to give mother opportunity to stop drug taking, to have a healthy pregnancy
How can Heroin/ MSTI/ Homebake have a teratogenic affect on pre-natal babies?
Withdrawal= high pitch crying, increased muscle tone/hypertonic, irritable, non-nutrient sucking (no-co-ordination and just clench - end up losing weight)
SIDS "cot death"
How can Methadone/ Buprenorphine have a teratogenic affect on pre-natal babies?
Withdrawal=high pitch crying, increased muscle tone/hypertonic, sucking (no-co-ordination and just clench - end up losing weight)
SIDS "cot death" (as is a depressant)
What things have a higher risk, in babies exposed to Tobacco?
Higher risk of:
Low birth weight
Higher risk of Pre-term birth
Higher risk for SIDS "cot death"
Higher risk of Diabetes
Higher Childhood blood pressure
Reduction in Gray matter
What abnormalities can Teratogenic Pre-natal Tobacco exposure lead to?
CNS Functional Abnormalities or Developmental Problems:
1. Increased internalising(depression) and externalising(aggression) behaviours
2. Increased ADHD and Conduct disorders
3. Increased Aggression
What are some examples of Teratogens?
In what ways can alcohol have a teratogenic effect on pre-natal babies?
Most evidence, don't know dose but know it does cause in high dosages during pregnancy
LBW - small head circumference
Developmental delay in an number of areas
Poor Social Learning behavioural problems
Fetal Alcohol Spectrum Disorder (FASD)
Worst outcome : (FAS) = Fetal Alcohol Syndrome
What does FASD stand for?
Fetal Alcohol Spectrum Disorder
What does FAS stand for?
Fetal Alcohol Syndrome
Worst outcome of alcohol
requires heavy drinking Consistently during pregnancy
What is Fetal Alcohol Syndrome?
Worst teratogenic outcome of alcohol on Prenatally exposed babies
Leads to CNS Dysfunction and Organic Brain Damage
Lead to Growth Deficiency- Neuronal connections made- and a Specific Pattern of Facial anomalies
What are the 6x outcomes of FAS?
1. hyperactive, attentional deficits
2. intellectual deficits, learning disorders
3. problems with memory, language and judgement
4. Developmental delay, microcephaly
5. Fine and Gross motor problems, seizure disorder
6. Mental retardation, structural brain damage
How does alcohol cause brain damage?
Excessive Brain cell death (especially during embryonic period)
Reduced cell proliferation
Migrational errors in brain development
Inhibition of nerve growth factor
Disruption of neurotransmitters
What is the comparison of 12 years of age of brains of prenatally exposed and non-exposed children?
Effects were ADDITIVE
More drugs = Less gray matter = smaller brains
More disrupted neuronal pathways
What is the equation which results in Poor outcomes for children?
Poor Outcomes for children = 1. Substance abuse + 2. Psychopathology + 3.Toxic Environments
Which drugs are addictive?
Methamphetamine and amphetamine
not sure if E is addictive
What are man made drugs?
danger: made in laboratories out of different products
How do you get the feel good feeling ecstasy biologically?
Targets the Transporters
The transporters stop serotonin being taken back into cell/increase the amount of serotonin in the synapse
This increased level of synaptic serotonin makes the neurons fire like crazy
Which is what the "feel great feeling" is
When do teratogens have the most effect on prenatal babies?
Babies are Most vulnerably during embryonic period when the most changes are going on - problem as most people don't figure out they are pregnant by that time (weeks 3-8) and are already exposing the baby to drugs
If two mother both take drugs how can their effect on their baby differ?
Dependant on the timing during their pregnancy as to the greatest effect
baby could be less effected if exposed outside if the Embryonic period vs exposed during the Embryonic period when they are most vulnerable
What are withdrawal drugs?
Methadone and Buprenorphine
high pitch crying, increased muscle tone/hypertonic, sucking (no-co-ordination and just clench - end up losing weight)
May have an ongoing withdrawal or have a latent affect
What order is substance abuse and psychopathology in?
could be one way or another
because drugs have an action and a reaction
therefore you have one affect with the drug an then the opposite affect without the drug, which can cause you to want the drug again (cyclic affect)
What does toxic environment include?
toxic from drugs
but also toxic from drug abuse/law involvement
Which model are teratogens considered part of?
Medical model approach