AP Psych - 1.3: Neurontransmitters, Endocrine System, Drugs

Neural Transmission (Firing Neurons)

Electrochemical process where signals are sent through the axon of the neuron.

Inside = Electric Outside = Synaptic

Polarization

Neurons have a polar membrane with negative voltage on the inside and positive voltage on the outside

Threshold

The minimum level of stimulation required to trigger an action potential in a neuron, once hit neuron is fired

Action Potential

Acutal firing of neuron

Depolarization

Membrane opens up for positive ions to enter and negative ions to leave (switch)

Repolarization

The negative and positive ions switch again after sending the signal

Hyperpolarization (Refractory period)

The process where the membrane potential becomes more negative than the resting potential, making it less likely for the neuron to fire. Waiting period for voltage to change

Excitatory NTs

excite the neuron into firing

Inhibitory NTs

inhibit the next cell from firing

Reuptake

neurons going back after doing their job

Glutamate

• Excitatory - stimulates neuron to fire forward

• Associated with memory and learning

• Most abundant

Acetylcholine

• Excitatory

• Associated with movement, learning, and memory

• Linked with alzheimers

• Most abundant active NT

Substance P

• Excitatory

• Associated with sending body signals about pain

• Important for body’s response to stress'

• Surplus - can contribute to anxiety and heightened stress response

• Deficiency - can lead to increased pain sensitivity

Norepinephrine

• Excitatory NT and Hormone

• Associated with arousal and hypervillaglence

• Linked with fight, flight, freeze response

• GABA tries to turn this down

• Surplus - can lead to anxiety and hyperactivity

GABA

• Inhibitory

• Helps balance out other NTs (norepinephrine)

• Deficit - can lead to anxiety, seizures, and insomnia (trouble sleeping)

Dopamine

• Mainly inhibitory, but can be excitatory

• Associated with pleasure, addictions, and regulating movement

• Surplus - can lead to schizophrenia and risk-taking behavior

• Deficiency - can result in Parkinson's disease and ADHD

Endorphins

• Inhibitory

• Associated with Endogenous Morphine and pain perception

• Surplus - body may not be alerted to pain

• Deficit - body may experience more pain

• 
  

Epinephrine (adrenaline)

• Inhibitory NT and Hormone

• Associated with fight, flight, freeze response to stress

• Surge in energy

Serotonin

• Inhibitory

• Associated with regulating mood, sleep, hunger, and easing pain

• Surplus - can lead to increased irritability and anxiety

• Deficiency - is linked to depression and mood disorders

Endocrine System

A network of glands that produce and release hormones to regulate various body functions. Works with the nervous system to maintain homeostasis.

Pitutary Gland

• Master gland that tells other glands when to release hormones

• Produces HGH: (somatotropin) growth of bones and tissues, regulates metabolism and body composition

• Produces Oxytocin: important for love and connection

  • controls reproductive system and social behavior

Pineal Gland

• Produces melatonin: helps create drowsy feeling to encourage sleep

  • Natural production can be altered by light exposure and supplementation

Thyroid

• Produces hormones like thyroxine (T4) and triiodothyronine (T3) that regulate metabolism, energy levels, and growth

• Primary gland that influences metabolism

Thymus

• Creates hormones that produce T Cells which are responsible for the immune system

• T Cells (white blood cells) are attacked when someone has HIV

Pancreas

• Helps digest food and control blood sugar

• Insulin: converts food into energy and lowers blood sugar

• Glucagon: helps increase blood sugar in the absence of food

Adrenal Gland

• Controls responses to stress

• Cortisol: stress hormone

• Epinephrine and Norepinephrine activated in flight or fight situations of sympathetic NS

Gonads (Ovaries and Testes)

Numerous hormones - estrogen and testosterone

Psychoactive Drugs

Chemicals that change the chemistry of the brain and body by physiological processes or placebo effect

Blood Brain Barrier

A tightly packed layer of cells bt the bloodstream and CNS that protects the brain from harmful substances while allowing essential nutrients to pass through but sometimes small drug molecules pass through

Agonist: Enhance NTs

• Chemicals that fit into the receptor sites of neurons and act as NTs

  • Brain can’t tell real from fake

• Reuptake inhibitors prevent NTs from going back to vesicles

Antagonist: drug that blocks NTs

• Chemicals that fit into receptor sites and prevent NTs from getting in or block terminal branches from releasing NTs

Tolerance

• Building a tomerance: needing more to get the same desired effect

• Leads to withdrawal symptoms bc undesirables side effects occur when body stops getting drugs

Addiction

Psychological dependency: you think you have to have it

Physical dependency: physical withdrawal symptoms

Depressants

• Slows the CNS by creating drowsiness or sleep & reducing anxiety

• Ex: Alcohol (agonist for GABA) & Benzodiazepines (anti-anxiety drugs)

Opiates

• Agonists for endorphins

• Some of the most physically addicting drugs

• Ex. Heroin, Oxy, Fentanyl

Stimulants

• Speeds up/activates the CNS

• Agonist for dopamine

• Antagonist for NT for sleep (blocks sleep NTs from firing)

• Ex. Caffeine, Cocaine

Hallucinogens/Psychedelics

• Alter perception of reality, mood, indentity

  • Hallucinations, fantasies

• Drugs linger in body for weeks bc each new amount is added on to previous

• Ex. THC, MDMA, Psilocybin