Protein molecule that pumps substances across a membrane.

From adrenaline, Latin for epinephrine; a neuron containing norepinephrine.

Guanyl nucleotide–binding protein coupled to a metabotropic receptor; when activated, binds to other proteins.

Amino acid neurotransmitter; typically inhibits neurons.

Mood disorder characterized by prolonged feelings of worthlessness and guilt, disruption of normal eating habits, sleep disturbances, a general slowing of behavior, and frequent thoughts of suicide.

Self-receptor in a neuronal membrane; that is, it responds to the same transmitter released by the neuron.

Behavior characterized by compulsively repeated acts (such as hand washing) and repetitive, often unpleasant, thoughts (obsessions).

Chemical with an excitatory or inhibitory effect when released by a neuron onto a target.

Any chemical in limited supply that restricts the pace at which another chemical can be synthesized.

Neurotransmitter that accelerates heart rate in mammals; found in the brain and in the sympathetic division of the ANS.

Neuron that uses acetylcholine as its main neurotransmitter; cholinergic applies to any neuron that uses ACh as its main transmitter.

Amine neurotransmitter; helps to regulate mood and aggression, appetite and arousal, perception of pain, and respiration.

Quick-acting neurotransmitter synthesized in the axon terminal from products derived from the diet.

Gaseous neurotransmitter; slows cellular metabolism.

Degenerative brain disorder related to aging that first appears as progressive memory loss and later develops into generalized dementia.

Gap separating the neuronal presynaptic membrane from the postsynaptic membrane.

Membranous compartment that holds several vesicles containing a neurotransmitter.

Chemical messenger that acts as a neurotransmitter in the CNS and as a hormone to mobilize the body for fight or flight during times of stress.

Junction at which messenger molecules are released when stimulated by an action potential.

Membranous compartment that encloses a quantum of neurotransmitter.

Embedded membrane protein; acts as (1) a binding site for a neurotransmitter and (2) a pore that regulates ion flow to directly and rapidly change membrane voltage.

Short (fewer than 100), multifunctional amino acid chain; acts as a neurotransmitter and can act as a hormone; may contribute to learning.

Relatively permanent change in behavior that results from experience.

Embedded membrane protein with a binding site for a neurotransmitter linked to a G protein; can affect other receptors or act with second messengers to affect other cellular processes, including opening a pore.

Area of contact between adjacent cells in which ion channels form a pore that allows ions to pass directly from one cell to the next.

Chemical that initiates a biochemical process when activated by a neurotransmitter (the first messenger).

First neurotransmitter discovered in the PNS and CNS; activates skeletal muscles in the SNS; may either excite or inhibit internal organs in the ANS.

Syndrome characterized by physiological arousal associated with recurrent memories and dreams arising from a traumatic event that occurred months or years earlier.

Amount of neurotransmitter, equivalent to the content of a single synaptic vesicle, that produces a just-observable change in postsynaptic electric potential.

Neurotransmitter that controls arousal and waking; can cause the constriction of smooth muscles; when activated in allergic reactions, constricts airway and contributes to asthma.

Amino acid neurotransmitter; typically excites neurons.

Gaseous neurotransmitter; activates cellular metabolism.

Axon terminal membrane on the transmitter, or output, side of a synapse.

Deactivation of a neurotransmitter when membrane transporter proteins bring the transmitter back into the presynaptic axon terminal for reuse.

Behavioral disorder characterized by delusions, hallucinations, disorganized speech, blunted emotion, agitation or immobility, and a host of associated symptoms.

Learned behavior in which the response to a stimulus weakens with repeated presentations.

Neural pathways that coordinate brain activity through a single neurotransmitter; its cell bodies lie in a brainstem nucleus; axons are distributed through a wide CNS region.

Protein that has a binding site for a specific neurotransmitter and is embedded in the membrane of a cell.

Learned behavior in which the response to a stimulus strengthens with repeated presentations.

Gaseous neurotransmitter; acts, for example, to dilate blood vessels, aid digestion, and activate cellular metabolism.

Disorder of the motor system correlated with a loss of dopamine from the substantia nigra and characterized by tremors, muscular rigidity, and a reduction in voluntary movement.

Class of lipid neurotransmitters, including anandamide and 2-AG, synthesized at the postsynaptic membrane to act on receptors at the presynaptic membrane; affects appetite, pain, sleep, mood, memory, anxiety, and the stress response.

Amine neurotransmitter involved in coordinating movement, attention, learning, and in reinforcing behaviors.

Disordered mental state of extreme excitement.

Membrane on the transmitter, or input, side of a synapse.

Protein molecule that assembles with other protein molecules.