Brain Neuroplasticity and Drug Abuse Flashcards
what circuit is the main target for drugs of abuse
striatolimbic reward circuit
what are the 3 areas linked by the striatolimbic reward circuit
VTA, NAc and ventral pallidum
what are the NAc, VTA and ventral pallidum linked via
medial forebrain bundle
describe the striatolimbic reward circuit
- descending myelinated, glutamate driven from anterior bed nuclei to VTA
- ascending dopaminergic VTA to NAc
- GABA/substance P/ enkephalinergic from NAc to ventral pallidum
what do all addictive drugs do?
increase dopamine levels in the NAc
Cocaine, amphetamine, ecstasy mechanism of increasing dopamine levels
inhibit dopamine reuptake in the NAc
how does nicotine increase dopamine levels in the NAc`
depolarizes VTA dopaminergic neurons
how do opioids, GHB, benzos, and cannqbinoids increase dopamine levels in the NAc
hyperpolaize VTA GABAergic interneurons
Where is the NAc located
basal forebrain striatim
where is VTA located
midbrain
where is the PFC llcated
frontal love, extends into medial regions
where is the hippocampus located
para-saggital plane, caudal amygdala
where is the locus coeruleus located
dorsal pons
where is the raphe nuclei located
dorsal medulla oblongata
what is the NAc
pleasure centre, motivation, cognitivie processing of aversion
where does the NAc have recipirocal projections to
VTA, hippo, amy PFC bg
what projections from the NAc are responsible for pleasure planning and inhibiton
bg, brainstem, PFC
which area is the interface between the limbic and motor systems
NAc
wHAT does the VTA do?
cognition, motivation, locomotor behavior
which area of the brain is the main driver of rewarding feelingd
VTA
which areas does the VTA have reciprocal projections to
NAc, amy, RN, PFC, basal gangglia
what is the PFC functions
self-awarenessm planning, problem solving, personality, social behavior
what projection expressed behaviors trained by chronic drug use?
PFC -> VTA + amygdala
reciprocal connections in the PFC are associated with
ateention action cognition
disfuction of the PFC is associated with
bipolar, schizo
what is the hippocampus used for
memory formation, processing
which area of the brain conttains neuronal stem cells
hippo
how do drugs of abuse affect neuronal stem cells
suppression
which projections modulate plasticity and learning/memory
VTA -> HIPPOCAMPUS
WHAT is the main funtion of the amygdala
emotions, fear, pleasure, learning memory, arousal, sress
amy -> PFC connections are disrupted by
chronic drug use
what does the basolateral amy do? how?
permits emotional regulations, medial PFC
what is the CN responsible for
VOLUNTARY movement, learning, memory, sleep PAIN
WHERE do drugs accumulate and bind trasnporters
CN`
where does the CN have reciprocal connections to
VTA NAc hippo, amy
which area regulates the sleep-wake cycle
LC
where does the LC project toV
VTA, brainstem, cerebellum, thalamuc, hypothalamus, hippo, amy, basal ganglia, cortex and spine
LC-NE afferents are modulated by K opioid receptor activation resulting in
stress
which area might target a number of withdrawal symtoms
LC
where does the RN project to
hypothalamux, limbic system, braisntem and spine
RNnuclei and forebrain projections are targets of…
alcohol opioids MDMA and others
which projection is impolicated in neuropsychiatric disorders like OCD and ADHD
RN –> PFC
impulsivity is a result of deficient…
frontostriatal “top-down” cognitive control
which area is mainly involved in impulsivity
dosrolateral prefrtonal
what is the state effect?
acute and chronic use change brain structure and function
what is compulsivity?
tendency towards repetitive habitual actions repeated despite adverse consequences
which projections are at the core of the reward circuit
VTA —> NAc DA-ergic
which circuits are at the core of anticipation circuits
frontal inputs
who coined the term plasticity
JERZY KONORSKI 1948
`what are the critical neurotransmitters of addiction
dopamine and glutamate
what is the shift for drug seeking behavior
ventral striatum to doral striatum
how is addiction triggered?
reward circuit activation + neuroplasticity
