Chemical Messengers

Neurotransmitters

chemical messengers that transmit signals between neurons, allowing for communication within the nervous system

Glutamate

primary excitatory neurotransmitter in the CNS

• key role in synaptic transmission and neuronal communication

• involved in various brain functions including learning, memory, and neural plasticity

ex: study for test and engage in learning new information; brain releases glutamate in regions associated with memory formation, such as hippocampus

Inhibitory Neurotransmitters

chemicals released by neurons that decrease the likelihood of an action potential occurring in postsynaptic system

• like a pedal break - slows things down

GABA

neurotransmitter that acts as a primary inhibitory neurotransmitter in CNS

• promotes relaxation and reduces anxiety

Dopamine

regulates mood, reward, motivation, and movement

• experience of pleasure and reward

ex: hearing a phone notification - release of dopamine is triggered in brains reward pathway - makes you want to check your phone again

Serotonin

plays a vital role in regulating mood, sleep, appetite, and stress

• influence mood and emotional well-being

ex: spending a sunny day outside - brain releases serotonin which contributes to feelings of happiness

Endorphins

act as natural pain relievers

• released in response to stress, pain, or intense physical activity

Substance p

transmits pain signals to the nervous system

ex: accidently touching hot stove, substance p is released

Acetylcholine

involved in various functions like muscle contraction, memory, and learning

ex: playing basketball - acetylcholine enables coordination of muscle activity

Hormones

produced by glands in the endocrine system

• regulate various physiological processes and behaviors

ex: difference between men and women

Ghrelin

hormone produced by stomach - “hunger hormone”

• stimulates appetite and promotes hunger

Leptin

hormone produced primarily by fat cells

• regulates energy balance and appetite

• suppresses hunger

Melatonin

hormone that regulates sleep-awake cycle and circadian rhythm

• rise in melatonin - feel tired

Oxytocin

social bonding - “love hormone” or “bonding hormone”

Adrenaline

body’s stress response - often referred to as “fight or flight”

ex: playing piano at a recital; adrenaline kicks in causing heart rate to rise

Norepinephrine

helps the body stay alert and focused

• key role in fight or flight response

ex: big test coming up - feel more awake, alert, and ready to focus