Neurotransmitters are chemical messengers in the brain

• after connecting to the reciving receptor and sending the message, returns to presynaptic neuron through reuptakes

Two main types:

• Excitatory : causes the recieving cell to increase neural firing

• inhibitory : causes the recieving cell to decrease neural firing

Serotonin - inhibitory

What is its function?

• regulates mood, sleep and wakefulness, eating and aggressive behaviors

what happens if theres not enough serotonin?

→ mood disorders (ex: depression)

• Anxiety

• insomnia

• OCD

NOREPHINEPHRINE - excitatory

• what is its function?

• Arousal of the fight or flight response

• stress, arousal, eating

• enhances attention and memory for emotionally charged events

→ causes you to have adrenaline

What happens if theres not enough?

• depression…

what happens if theres too much?

• anxiety

• stress

• nervous tension

(parasympathetic)

if the situation is scary → the sympathetic nervous system kicks in

Acetlycholine (ACH) - excitatory

• function - skeletal muscle contractions, regulates heart muscles

• transmits messages between brain and spinal cord

• memory formation, learning general intellectual functioning

What happens if theres not enough

• low arousal and attention

• Alzheimer’s disease

What happens if theres too much

• violent muscle contractions/spasms

  ---

  Glutamate - excitatory

• its function is to enhance transmission

GABA - inhibitory

• Inhibitory neurtransmitter (provides balance)

• balances and offsets other excitatory messages

• regulate sleep wake cycle

what happens if theres not enough

• anxiety

• siezures, tremors

• insomnia

what happens if theres too much?

• sleep disorders

• some eating disorders

Endorphins

• what is its function?

  • natural opiate

  • regulate pain perceptions

  • released during excersize and linked to positive emotions

    • what happens if theres not enough

      • feel pain

    • what happens if theres too much

      • artifical highs

      • may not recieve adequate warning of pain

Dopamine - BOTH

function = voluntary coordinated motor movements

• attention, learning memory

• emotional arousal and reward

  • what happens if theres not enough?

    • parkinsons disease

    • depression

  • What happens if theres too much

    • Schizophrenia and shizophrenia like symptoms

    • addiction

    • bipolar disorder

    • ADHD

Substance P

• modulation of pain

• causes the contraction of smooth muscle and dilation of blood vessels

• acts as a potent NT, esp in the transmission of signals from pain receptors

• ex. if a persons arm is severed, the brain will stop the pain.

(in awe God is so good, God created us so perfectly)

Hormones

• chemical messenger that travels through bloodstream

• released by glands in encrine system

• affects the brain and other parts of the body

  • Growth, reproduction, metabolism, mood

  • Slower transfer than neurotransmitters but effects last longer

  Think email versus “snail” mail

Adrenaline

• increases heartbeat rate and strength, stimulates respiration

• fight or flight

• also refered to as epinephrine

Melatonin

• regualtion of circadian rhythyms

• release increases feelings of sleepines

Ghreline

• released by hypothalamus

• signals hunger and need to eat

Leptin

• released by hypothalamus

• allows you to feel “full”

Oxytocin

• stimulates uterine contractions and lactation

Certain drugs interact with the CNS in different ways

Can alter mood, perception, and behavior

Drugs can range from caffeine to LSD

the varying effects of drugs

• Dependence

  Psychological- Mental need for the drug

  • Physical- Feeling of physical need for drug to function

  • Addiction

  • Compulsive substance use (or behavioral patterns) that continue despite harmful consequences

• Withdrawal

  The discomfort and distress that follow discontinuing an addictive drug or behavior

  Tolerance

  As the brain’s chemistry adapts to offset the drug’s effect, it takes more and more of a drug to get us to feel the same effect

drug categories

• depressants

  • drugs that reduce neural activity and slow body functions

  • Ex: alcohol, Barbiturates (tranquiizers), opiods

• Stimulants

  • drugs that excite nerual activity and speed up body functions

  • Ex. Cocaine, ecstasy, methamphetamine, caffiene, nicotine

hallucinogens

• psychedelic drugs that distort prceptions and evoke sensory images in the absense of sensory input

• ex: LSD, ecstasy, marijuana (THC)

Opiods

• opium and its derivatives; depress neural activity, temporarly lessening pain and anxiety

• Ex: heroin, methadone (oxycontin, vicodin, morphine) fentanyl.