RXRS week 1 lecture

human brain

• most complex organ

• 3lb mass of gray and white matter

neurons

highly specialized cells for processing and transmission of cellular signals through electrical and chemical sginaling

• billion

• each one acts as switch controlling flow of info

• neurons recieve signals from others and fires send own signal to other neurons

neurotransmitters

chemical messengers that carries, boost, and balance signals between neurons and other cells in the body

synapse

gap between neurons and space neurotransmitter released

transporters

recycle neurotransmitters by returning them to the neuron that releases them effectively limiting or shutting off the signal between neurons

8 neurotransmitters

adrenaline, noradrenaline, dopamine, serotonin, gaba, acetylcholine, glutamate, endorphin

adrenaline

fight or flight neurotransmitter

noradrenaline

focus/ concentration neurotransmitter

dopamine

pleasure neurotransmitter

serotonin

mood neurotransmitter

gaba

calming neurotransmitter

acetylcholine

learning neurotransmitter

endorphin

euphoria neurotransmitter

preflight check

• way for body to have stress response

• response to stress fear danger and excitement

• cascade of hormones from thalamus and amygdala triggers hypothalamus to prep the body for confrontation

panic

• trigger

  • panic attacks can have single trigger without warning and stress and anxiety builds

• interpreting danger

  • brain construes the feeling as danger and release fight or flight

• physical effect

  • physical sensation occur in response to hormone release- increase in heart rate, rapid breathing, pupil dilation

• anxiety builds

  • unaware of the triggers and unsure why it is happening anxiety increases

• symptoms increase

  • more hormones are released and symptoms worsen, increasing anxiety further

• panic attack

  • left unchecked this can spiral into full blown panic attack

  • sufferers may fear they are dying

brain and body connections

• different brain circuits responsible for coordinating and performing functions

• networks of neurons send signals back and forth among different parts of body

2 main pathways

• central nervous sytem

• peripheral nervous system

central nervous system

brain and spinal chord- master control unit for the body

peripheral nervous system

brain and spinal chord and nerves in body- body’s link to the outside world

nervous system

coordination of information and direction of responses

autonomic

controls self regulated actions of internal organs and glands

somatic

controls voluntary movement of skeletal muscles

sympathetic

arousing fight or flight prepares the body for stress

parasympathetic

calming, helps the body conserve energy

how do drugs work in the brain

• interferes with how neurons send and recieve signals through neurotransmitters

• cannabis and opium activate neurons bc their chemical structure mimics the body’s natural neurotransmitters

• allows drugs to attach and activate neurons

• meth and cocaine cause neurons to release large amounts of natural neurotransmitters or prevent recycling of brain chemicals by interfering with transporters

basal ganglia

plays important role in positive forms of motivation including pleasurable effects

• reward circuit

• repeated exposure causes circuits to adapt to drug

extended amygdala

plays role in stressful feelings like anxiety irriability which characterize withdrawal after drug high fades and motivates person to seek drug again

• becomes sensitive overtime

prefrontal cortex

powers ability to think plan and solve problems. shifting balance with reward and stress centers make person with addiction seek drugs compulsively with reduced impulse control

characteristics of neuroplasticity

• varies by age, younger=better

• involves variety of process

• can happen for learning or damage to brain

• environment plays role

• not always good

2 types of brain plasticity

• functional

  • ability to move functions from a damaged area of the brain to other undamaged areas - trauma

• structural

  • the ability to change its physical structure as a result of learning

drug

any substance that changes mental state or bodily functions

licit

within the law- legal: caffeine, nicotine, alcohol

illicit

• illegal

• drugs that pose threat to ones health so classified as ilegal

• heroin, cocaine, methamphetamine

prescription

pharmaceutical drug that legally requires medical prescription to be dispensed

over the counter

drugs obtained without prescription

food drugs

• functional

  • foods that have potentially positive effect on health beyond basic nutrition

• nutraceutical

  • food or fortified food product that not only supplements diet but assists in treating or preventing disease

• probiotic

  • living microorganism that when ingested provides numerous health benefits

drug class

a set of medications that have similar chemical structures, the same mechanisms of action, a related mode or aciton and are used to treat the same disease

agonists

drug which intiates a physiological response when combined with a receptor

anabolic androgenic steroid

steroidal androgens that induce natural androgens

analgesic

drugs used to relieve pain

anesthetic

drugs used to induce temporary loss of sensation or awareness

antagonist

drug that inerferes with or inhibits the physiological action of another

anxiolytic

antipanic or antianxiety drugs

hallucinogen

drugs that alter perception: awareness of surrounding objects and conditions, thoughts and feelings

herbal

plant or plant par used for its scent, flavor, or therapeutic property, dietary supplement

hypnotic or soporific

drug whose primary function is to induce sleep and are used for surgical anesthesia

nitrites

inhalants that perform wide dilation of blood vessels and relax gthe muscles, used for their body sensation used to intensify sexual pleasure

pscyhoactive or pscychotropic

drugs that changes brain funciton and results in alterations in perception, mood, consciousness, cognition or behavior

sedative

drugs taken for its calming, sleep inducing or tranquilizing effect

stimulant

drugs that increase activity of the central nervous system and the body, drugs that are pleasurable and invigorating or have sympathetic nervous system effects

poison

any chemical harmful to health can be synthetic or naturally available

toxin

harmful substance produced by living organims

dose

the amount of drug taken at any one time- 250 mg

dosage

frequency at which drug doses are given- 2.5ml twice a day

dose response

describes change in effect on an organism caused by differing levels of exposure (doses) to a stressor (usually chemical) after certain exposure time, or to a food

pharmacodynamics

describes effects of drugs on the body intentional or toxic

pharmokinetics

describes the movement of the drug throughout the body- bodys effect on drug

pharmacogenomics

the study of the role of genetics in drug response- determining the right drug in the right dosage at the right time for each patient

PK- physical disposition of drug

how body eliminates

• absorption: how drug is absorbed in bloodstream

• distribution: movement of drug from blood and various tissue of body

• metabolism: metabolic breakdown od drugs

• elimination: how drug gets eliminated either in unaltered form or modified as metabolite

PD

refers to extention of pharmacologic effect of the drug resulting in enhances toxicity or in antagonism of two agents- what drug does to body

ROA- route of administration

external: oral, rectal

parenteral: intravenous- needle

transdermal: epidermic- skin

inhalation: vaporizer

tolerance

reduced reaction to drug following repeated use

sensitization

increased effect of drug following repeated doses

prolonged drug use makes changes in

liver, brain, behavior

quality control

in production and distribution of illegal drugs, quality control practice are deficient or nonexistent

withdrawal

constellation of symptoms that occur upon abrupt discontinuation or decrease in intake of medications or recreational drugs