W3-synapses, drugs, addiction
Card Set Information
W3-synapses, drugs, addiction
synapses drugs addiction
How drugs, addiction affect the synapses
Most drugs work at the?
*except anesthetics that block Na+ channels, that stop action potentials to propegate- =membrane stabilizers
most abused drugs come from? and either inhibit or____ transmission of NT
a: plants b: facilitate
Drugs can stimulate or block ____ receptors?
*can block or breakdown NT at the synapse
*can increase or decrease synthesis of NT
*can cause vesicles to leak
*can block reuptake of NT back into the presynaptic cell
Nucleus accumbens- important for ?
Many axons that input into this area release what?
: receiving pleasure
: dopamine or NE
Nucleus accumbens is activated when?
-sexual excitement, gambling, habitual video player, other drugs
motivation, may want a pHd but don't enjoy getting it
enjoying the experience, but don't always want it
The bigger parts of the nucleus accumbens responds more to the?
addictive drugs activate nucleus accumbens by releasing what?
DA or Ne on to it
Stimulant drugs increase concentration of DA in the synapses in the NA
Amphetamine & cocaine block protein therefore increasing the DA concentration
Amphetatime has some similar effects on 5-HT and NE transport proteins and Methamphetamines have a ____ effect than Amphetamine
Stimulants make you feel depressed after use because?
The DA is washed away and the brain can't make Dopamine fast enough so you end up with a deficit of DA in the Synaptic cleft
What is the synaptic cleft?
This is the junction between two neurons. At the one end you have the
pre-synaptic membrane - the terminal end of the previous neuron, the
pre-synaptic neuron - and on the other side you have the post-synaptic
membrane, part of the post-synaptic neuron. Action potentials typically
cross the cleft by the use of neurotransmitters.
Stimulants: high doses impair attention, learning, depression
low doses = good for
Rx of ADHD- enhances attention
Methylphenidate(Ritalin) blocks what?
reuptake of DA and NE
-*injecting ritalin = same effect as cocaine
Methamphetamine: Increases DA in Syn-cleft
-medically approved low dosage for ADHD & obesity(desoxyn)
*high doses = mania, grandiosity, increased libido
*increases Parkinsons Dz, cognitive deficits, impairs attention/memory. 20% experience psychosis like schizophrenia -difficult to treat
-*LONT-TERM = depression, suicide, heart, "meth mouth"
stimulates Ach receptors = Ach receptor
*releases DA and NE in nucleus accumbens
*used as an insectiside
morphine, heroin, methadone
OPIATES - brain produces its own version called__?
B: relaxation, pain relief, decreased anxiety
Opiates ___ activate DA release. Endorphins ____ neurons that release ___?
a: inderectly b: inhibit c: GABA
*GABA- inhibits firing neurons that release DA, so by inhbiting the inhibitor GABA the effect increases DA release
Marijuana contains? and affects are?
*good for appetite, pain, & nausea
-But impairs memory & cognition- betters with 4 weeks after stopping use
Marijuana- has very few Cannabinoid receptors in the Medula so it doesn't have much of an effect on____?
heart rate, or breathing like opiate receptors
Marijuana receptors are located in the ___ neuron?
Marijuana: When the post-synaptic neuron is stimulated it releases the cannabinoid ---
The cannabinoid travels back to the presynaptic neuron & inhibits further release of eitehr glutamate or GABA
* so the chemicals in Marijuana decrease both
Inhibit & excite
transmissions in the synapse.
Marijuana- decrease inhibition due to ___?
decreased GABA release of neurons that release DA on Nucl-accumbens
Hallucinogenic Drugs =
LSD, - Extasy(MDMA) at low doses release DA similar to Amphetamine.
-Higher doses- affects 5-HT receptors. destroys neurons, increases body temp., life threatening
*long-term = loss of serotonin receptors, depression, anxiety, impaired learning/memory
What drugs block re-uptake of dopamine and other transmitters and also excite, elevate, & enhance alertness?
-Methylphendine(ritalin)- mainly just alerts
MDMDA (exctasy) - Low dose =
and High dose =?
a: stimulator = releases Dopamine
B: distorts senses = releases serotonin *damages axons containing serotonin
Nicotine = mostly stimulant effects... stimulates Nicotinic receptors that __?
increase DA in N-accumbens
Opiates; heroin, morphine- relax, withdrawl, decreased pain and stimulates _____?
Marijuana- alters senses, decrease pain/nausea, increased appetite and excites ____?
negative-feeback receptors in presynaptic cells: those receptors ordinarily respond to anandamide cells and 2AG
Hallacinagens - distorted sensations-- *stimulates ___?
serotonin type 2A receptors