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12 Cards in this Set
- Front
- Back
What is the reward pathway activated by? |
Food, water and sex, activities (such as sky diving,paragliding etc) and exercise |
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What neurotransmitters act on the reward pathway? |
Dopamine •Receptors: D1, D2 •Function: pleasure,euphoria, mood, motorfunction Serotonin •Receptors: 5HT3 Function: mood, impulsivity,anxiety, sleep, cognition Cannabinoids •Receptors: CB1, CB2 •Function: Pain, appetite,memory Opioid peptides (Endorphins,Enkephalins)•Receptors: Kappa, Mu, Delta •Function: pain |
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What is the final activation chemical? |
Dopamine. |
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What anatomical sites are these neurotransmitters involved in when it comes to the acutereinforcing effects of drugs of abuse? Dopamine, opioid peptides, GABA and glutamate? |
Dopamine: Ventral tegmental area,nucleus accumbens Opioid Peptides: Nucleus accumbens,amygdala, ventraltegmental area GABA: Amygdala Glutamate: Nucleus accumbens |
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How does the ventral tegmental area (VTA) work? |
• The VTA receives information from several other regionsthat tell it how well various fundamental needs, and morespecifically human needs, are being satisfied. • The VTA then forwards this information to anotherstructure further forward in the brain: the nucleusaccumbens. To send this information to the nucleusaccumbens, the VTA uses a particular chemicalmessenger: dopamine. |
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What does the magnitude of the effect of a drug depend on? |
The number of existing receptors |
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What is the mechanism of cocaine? |
• The mechanism of action for cocaine is viareuptake inhibition of dopamine • Dopamine release is promoted via the proteinresponsible for the reuptake of dopamine(dopamine transporter; DAT) |
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Indirect drug action? |
• Drugs of abuse may modulate dopamine via otherreceptor system and neurotransmitters that thenmodulate a different system e.g. Alcohol• Binds to subreceptors GABAA: Dopaminergic activity iseventually increased in the VTA by inhibiting GABAergicinterneurons• Also binds to NMDA (glutamate receptor and ionchannel), activates secondary messages and has directserotonergic effects |
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Drug action and reward pathway for heroin? |
•Binds to opioidreceptors that inhibitGABAergic neuronsthat project todopaminergic neuronsin the VTA |
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Drug action and reward pathway for nicotine? |
•Activates cholinergicneurons that project todopaminergic neuronsof the VTA |
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What is withdrawal and what does this syndrome involve? |
• Withdrawal is the result of an abrupt cessation ofthe drug • This syndrome involves:– disturbance of the autonomic nervous system– activation of the thalamus– release of corticotrophin releasing factor (CRF)– activation of the locus coeruleus (LC) |
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The Development ofAddiction? |
• The use of the drug of abuse is increased to maintaineuphoria or to avoid dysphoria or withdrawal • The number of receptors gradually increases tocounter for the continual presence of the drug ofabuse • The amount of neurotransmitter gradually decreasesthrough depletion and feedback inhibition • The reinforcing properties of the drug are thusgradually decreased (tolerance)• The need for drug to maintain this new homeostasis istherefore increased (dependence begins) |