Neurotransmitters

acetylcholine

primary neurotransmitter used @ the neuromuscular junction & by most of the autonomic nervous system

biogenic amines

molecules synthesized from an amino acid by removal of the carboxyl group & retaining the single amine group; also called monoamines

catecholamines

a distinct group of biogenic amines that contain a catechol chemical group; originally described as hormones

dopamine

produces inhibitory activity in brain; important roles in cognition (learning, memory), motivation, behavior, & mood; decreased levels in Parkinson disease; amphetamines increase release; cocaine decreases removal from synaptic cleft; ecstasy increases release

norepinephrine

neurotransmitter of peripheral autonomic nervous system (sympathetic division) & various regions of CNS; amphetamines increase release; cocaine decreases removal from synaptic cleft; ecstasy increases release

epinephrine

has various effects in thalamus, hypothalamus, & spinal cord

indolamines

distinct group of biogenic amines that contain an indole chemical group

histamine

neurotransmitter of CNS; plays a role in sleep & memory

serotonin

has various functions in brain related to sleep, appetite, cognition (learning, memory), & mood; fluoxetine (Prozac) decreases reuptake, ecstasy increases release; LSD binds to most receptors

amino acids

molecules w/ both carboxyl (-COOH) & amine (-NH2) groups & various R-groups; building blocks of proteins; act as signaling molecules in nervous system

glutamate

excites activity in nervous system to promote cognitive function in brain (learning & memory); most common neurotransmitter in brain; stroke causes excessive release → neuron death

aspartate

excites activity primarily in descending motor pathways through spinal cord to skeletal muscle

serine

activates diverse areas in brain

gamma-aminobutyric acid (GABA)

modified amino acid synthesized from glutamate; primary inhibitory neurotransmitter in brain; also influences muscle tone; alcohol, diazepam (Valium), & barbiturates increase inhibitory effects

glycine

inhibits activity between neurons in brain, spinal cord, & eye; strychnine blocks receptors that bind this

neuropeptides

small molecules made of chains of amino acids; generally act through G proteins to cause more diverse effects

enkephalin

opioid that helps regulate response to something that’s perceived to be noxious or potentially painful

beta-endorphin

an opioid that prevents release of pain signals from neurons & fosters feeing of well-being

neuropeptide Y

involved in memory regulation & energy balance (increased food intake & decreased physical activity)

somatostatin

inhibits activities of neurons in specific brain areas

substance P

assists w/ pain info transmission into brain

cholecystokinin

stimulates neurons in brain to help mediate satiation (fullness) & repress hunger

neurotensin

helps control & moderate effects of dopamine

adenosine

part of a nucleotide; has an inhibitory effect on neurons in brain & spinal cord

nitric oxide

involved in learning & memory; relaxation of muscle in digestive tract; relaxation of smooth muscle in blood vessels

endocannabinoids

most prevalent receptors in brain