Lecture 4 Flashcards
What are the two dopamine pathways
Mesolimbic and mesocortical
Mesolimbic
route between VTA, Nucleus accumbens, and limbic system (hippocampus & amygdala)
* Key Pathway in Pleasure and Reward.
* Substance use
EMOTIONAL aspect of wanting to use a substance again
Mesocortical
route between VTA/Nucleus accumbens and PFC.
BEHAVIORAL aspect of going and getting drug
What hormone does stress release and how does that impact the brain
cortcotropin-releasing hormone (CRH) is released
* Strengthens the Amygdala (strengthens emotional response)
* Weakens the hippocampus & prefrontal cortex (hippocampus: don’t want to remember)
Ex. you don’t remember stress of taking drugs,
but remember how it feels good. Why so easy to relapse (especially since your PFC isn’t working)
What is the role of stress and substance use
You are then at greater risk for substance use
- Negative emotional state
- Lack of executive control =↑ risk of relapse
- Memory of relief/cravings
______ adol with reported abuse/neglect will develop a SUD before 18
1/3 adol with reported abuse/neglect will develop a SUD before 18.
_______ of those with PTSD developing chemical dependencies.
2-4x of those with PTSD developing chemical dependencies.
SGM across lifespan = ↑ risk of TUD and AUD + homelessness = ________ times
SGM: sexual and gender minorities
SGM across lifespan = ↑ risk of TUD and AUD + homelessness = 5x
COVID-19 = ↑ _______ increase in AUD
COVID-19 = ↑ 23% increase in AUD
CDC guidlines for drinking – is drinking okay?
Small amounts of drinking still ↑ risk of CVD-related illnesses BUT Risks attenuated by healthy lifestyle
(so a little is okay if you live healthy lifestyle)
Moderate drinking guidelines (CDC)
* Females = up to 1 drink per day
* Males = up to 2 drinks per day
Heavy Drinking
* Females = 8 or more per week
* Males = 15 or more per week
Binge Drinking (in 2-3 hours)
* Females = 4 or more
* males = 5 or more
Moderate drinking guidelines (CDC)
Moderate drinking guidelines (CDC)
* Females = up to 1 drink per day
* Males = up to 2 drinks per day
Heavy drinking (CDC)
Heavy Drinking
* Females = 8 or more per week
* Males = 15 or more per week
Binge drinking (CDC)
Binge Drinking (in 2-3 hours)
* Females = 4 or more
* males = 5 or more
Impacts of stimulants on the brain
Stimulants impact the brain’s levels of epinephrine/norepinephrine (E/NE), dopamine (DA), and serotonin (5-HT).
* Stimulants impact each to a varying degree (selectivity).
* Cause alertness, attention, energy.
Medical uses for stimulants
Several medical uses and rich history
History: Freud’s Uber Coca (he used and gave clients cocaine)
Pain management, ADHD, asthma, obesity, narcolepsy
Primary risk factors with stimulants
- Reduced seizure threshold
- ↑ BP, HR, HTN = ↑ risk of stroke, MI
- Poor appetite, mood swings, anxiety, insomnia
- Toxic levels = paranoia, psychosis
Endocannabinoid system
The endocannabinoid system comprises a vast network of chemical signals and cellular receptors that are densely packed throughout our brains and bodies. A neuromodulation system.
CB1 and CB2 Receptors
CB1 vs CB2
CB1 receptor –> THC
* ↑ in brain and lower conc. wide spread
* Mediates most of the psychoactive
effects of cannabinoids.
CB2 receptor –> CBD
* Principally involved in anti-inflammatory
and immunosuppressive actions.
Neuromodulator vs neurotransmitter
Neurotransmitter: a chemical used for a neuron-to-neuron communication
Neuromodulator: a chemical that affects the neurotransmission of a whole group of neurons
GROUP VS INDIVIDUAL
Phytocannabinoid
biologically active compound found in cannabis
Most notable cannabinoids: is delta-9 tetrahydrocannabinol (THC) & cannabidiol (CBD)
THC vs HEMP
THC Content = <.3% = hemp; >.3% = marijuana
Anandamide
an endocannabinoid (neuromodulator) found in the
endocannabinoid system.
- THC mimics anandamide –> effecting the endocannabinoid system.
- THC much more potent than anandamide
- Effects energy, mood, appetite, and perception of time.
Absorption: Cannabinoids
- Inhalation – peak plasma conc. 3-10 mins; bioavailability = 10%-35%
- Oral – peak plasma conc. ~ 120 mins, bioavailability = 6%- 20%
Distribution: Cannabinoids
- Rapidly to well-vascularized organs (where receptors for weed are concentrated)
- Accumulates in adipose tissue (body fat, exercise helps release)
Metabolism: Cannabinoids
- Predominantly hepatic (liver)
- Able to cross the placenta; released in breast milk
Excreted: Cannabinoids
- Excreted through urine, feces, and sweat.
What is the primary source of fuel for the brain?
And why is it important
Sugar! (aka glucose)
- ~20% of glucose-derived energy
- Is necessary - provides precursors for NT synthesis & apoptosis
- Glucose levels correlated with thinking, memory, learning
High sugar diets
High sugar diets = ↓ brain-derived neurotrophic factors (BDNF)
- BDNF modulates growth, development and communication between synapses.
- decreased levels of BDNF = ↑ risk of neurodegenerative d/os d/t atrophy and small vessel disease
How much sugar per year do americans consume and how many tsps are recommended per day
Americans consume 156 lbs of sugar per year
AMA recommends 6-9 tsps per day
Technology Addiction/”Internet Gaming Disorder”:
Teens aged 13-18 spent about ______ hours a day on screens
Teens aged 13-18 spent about 8.4 hours a day on screens
Technology Addiction/”Internet Gaming Disorder”:
What is addicting
“Likes”, “Re-Tweets”, “Novelty” = ↑ Mesolimbic Activation
- Need to check alerts = Compulsion?
Technology Addiction/”Internet Gaming Disorder”:
Increase use is associated with
↑ SUD, ADHD, Depression, Anxiety, poor coping
Technology Addiction/”Internet Gaming Disorder”:
Covid-19
Triggers: boredom, isolation, low self-esteem
Technology Addiction/”Internet Gaming Disorder”:
Center of Internet and Technology Addiction: assessments
Digital Distraction Test
Smartphone Compulsion Test
Virtual Addiction Test
The VMPFC is in charge of
Impulse Control, Courage, Moral-Decision Making
interface b/t emotional responses & control of complex behaviors (using emotional reactions to guide behaviors)
Patient E.R. with bilateral damage of the VMPFC
Excellent social judgment in VERBAL responses to hypothetical situations, expansive reasoning shared
Real life situations = unable to prioritize b/t trivial and important decision
AKA knew what was right, but not able to behave/do anything with that information
VMPFC and Courage
Courage = ↑ VMPFC Activation
VMPFC and impulsive and emotional murders
↓ VMPFC activation vs. Calculating/Careful (typical brain patterns)
VMPFC and antisocial PD
↓ 11% of gray matter in VMPFC
Photos of romantic partners does what to your brain
- ↑ Caudate Nucleus (processes visual information & controls movement)
- ↑ Ventral Tegmental Area (mediates reward system) = ↑ hyperfocus
When in love….
↑ Cortisol & Adrenalin
Increased HR, sweating, anxiety, nervousness
Decreased appetite, concentration
Dilated eyes
Love and PFC
↓ PFC activation (d/t “fight or flight”) = reduced social judgement and increased risk taking
Post orgasm in men and women
- In women: ↑ oxytocin = feelings of attachment & bonding
- In men: ↑ vasopressin = vigilance and need to guard/protect partner
Pharmacokinetics of Ethanol
Absorption: GI Tract = 20% stomach & 80% small intestine (several variables)
Metabolism: Primarily hepatic (90%) (see next slide for details)
Excretion = Urine
* Diuretic properties –> decreased nutrients & dehydration
Intoxication = consuming etoh faster than liver can break it down
Pharmacokinetics of Ethanol: metabolism
Metabolized by Alcohol Dehydrogenase (ADH) (requires B vitamins) –> Acetaldehyde
Acetaldehyde (toxic, carcinogenic, prevents absorption of nutrients) metabolized by aldehyde dehydrogenase (ALDH) –> Acetate
(Approximately 36% of East Asian subjects experience an alcohol induced flush reaction d/t deficient enzyme levels of aldehyde dehydrogenase.
