changes in brain from addiction

Addiction as a disease of a brain

• alt function of brain results from chronic use of drugs of abuse

• brain processes info using the rates of action potentionals in neruons

  • diff populations of neruons have diff things

How do drugs hijck brain

• alt domamngeric activity that alter how brain interacts with one and other

• many of these effects are the concequences of alt dopamergic activity and assocated changes in how systems in the brain are intereacting

  • dopamine plays many roles

    • VTA dompamine neurons provide generalized reward prediction error signal to cortex

    • VTA

• ETher changes in how much dopamine neurons (that release dopamine at their snyapeses) have action potentals

• or changes

What in the brain is changed in the pathological (diseased state)

• Changes in the amount of dopamine lead to changes in the systems where that sig means something

  • many systems fit that bill

• cahnges in responses becaome structural/functional changes in the system where that sig means something

Changes over time in dopamine

• Stumuli that leads to drugss of abyse are learned

• dopamine peredicts that these stimuli lead to reward

• This prediction signal tells the movement system what stimuli will lead to things we like/ want

Changes over time movement control

• the vta dopamine effects the nucleus accumbens shell 1st

• across rxperance / learning the response shifts to activate the core

• shell activation contributes to impulsive hibitual movements

• inhibitory feedback from NAc to VTA increases activity in diff dopamine

changes in mem/emotional systems

• VTA dopamine alters emotional amy digula resopnse

  • the neg emotion from withdrawl and craving araises in part

changes in prefrontal control

• prefontal cortex and anterior cingulate cortex are continually figuring out what the right thing to do is

  • descion making is

neurons change the strength of their connections

Progression

• reconational use

• intesified sustained escaltedc use

• loss of control

• not predeteremed thst any individual will progress