Lecture 4 Flashcards
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?
MDMA XTC E Essence Adam
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: Neo cortex Hypothalamus Basal Ganglia Amygdala Hippocampus
“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?
increases
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
Ongoing affects
Before: Normal
During Ecstasy: Elevated mood
After Ecstasy: depression like feelings, irritability, clouding thinking
What are the life threatening effects of ecstasy?
hyperthermia
arrhythmias
renal failure
death= due to “stacking” (overuse)
What are the Long term effects of Ecstasy?
Neurotoxic?
- Brain Chemistry changes:
a. Serotonin reduced
b. Serotonin metabolites reduced - 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?
- Genes passed from parents –> to child
- The environment of the womb
- The experiences a child has
What two questions to we want to know about drugs and the developing brain?
- who does prenatal exposure to different drugs and alcohol affect the developing brain and ongoing development?
- 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