Chapter 5 Terms

the process of transferring information from one cell to another at a synapse

a synapse in which electrical current flows directly from one cell to another via a gap junction

a synapse in which presynaptic activity stimulates the release of neurotransmitter, which activates receptors in the postsynaptic membrane

a specialized junction where a narrow gap between two cells that is spanned by protein channels called connexons that allow ions to pass directly from one cell to another.

a change in the posynaptic membrane potential by the presynaptic action of an electrical synapse or a synaptically released neurotrasmitter

a spherical membran encolse vesicle about 100 nm in diameter containing peptides intended for secretion by exocytosis

a dense accumulation of protien adjacent to and within the membrane on either side of a synaptic cleft

a presynaptic membrane differentiation that is the site of neurotransmitter release

a postsynaptic membrane differentiation that is the site of neurotransmitter receptors

a chemical synapse between a spinal motor neuron axon and a skeletal muscle fiber

the postsynaptic membrane at the neuromuscular junction

an amino acid and the major excitatory neurotransmitter in the central nervous system

an amino acid sythesized from glutamate and the major inhibitory neurotransmitter in the central nervous system

an amino acid and an inhibitory neruotransmitter at some locations in the central nervous system

an amine that serves as a neurotransmitter at many synapses in the peripheral and central nervous ststems including the neuromuscular junction

a membrane protein that ransports neurotransmitters or their precursors, across membranes to concentrate them in either presynaptic cytosol or synaptic vesicles

a membrane protein forming a pore that is permeable to Ca²⁺ ions and gated by depolarization of the membrane

the process whereby material is release from an intracellular vesicle into the extracellular space by fusion of the vesicle membrane with the cell membrane

the process by which a bit of the cell membrane is pinched off, internalized, and converted to an intercellular vesicle

a membrane protein forming a pore that is permeable to ions and gated by neurotransmitter

depolarization of the postsynaptic membrane potential by the action of a synaptically released neurotransmitter

a change in the postsynaptic membrane potential by the action of a synptically released neurotransmitter, making the postsynaptic neuron less likely to fire

a membrane-enclosed protein that binds guanosine triphosphate (GTP) when activated by a membrane receptor, when activated these proteins can simulate or inhibit other membrane-enclosed proteins.

a membrane protein that activates G-proteins when it binds neurotransmitter

a short-lived chemical signal in the cytosol that can trigger a biochemical response. Its formation is usually stimulated by a first messenger such as a hormone or neurotransmitter acting at a G-protein coupled cell surface receptor. Examples include cAMP, cGMP, and IP₃

a G-protein-coupled receptor whose primary action is to stimulate an intracellular biochemical response

a receptor in the membrane of a presynaptic axon terminal that is sensitive to the neurotransmitter released by that terminal

the study of the effects of drugs on the tissues of the nervous system

a drug or toxin that blocks the normal action of a protein or a biochemical process

a drug that binds to a receptor and activates it

a class of acetylchoine-gated ion channels found in various locations, notably the neuromuscular junction

the proce3ss by which multiple EPSPs and/or IPSPs combine within one ore postsynaptic neuron, in some cases triggering one or more action potentials

a change in postsynaptic membrane potential caused by the action of neurotransmitter released from a single synaptic vesicle

a method of determining how many vesicles release neurotranmitter during normal synaptic transmission

a smiple form of synaptic integration whereby excitatory postsynaptic potentials combine to produce a larger postsynaptic depolarization

the combining of excitatory postsynaptic potentials generated at more than one synapse on the same cell

the combining of excitatory postsynaptic potentials generated in rapid succession at the same synapse

a paramater used to describe how far changes in membrane potential can passivley spread down a cable such as an axon or dendrite. Represented by the symbol , it is equal to the distance at which depolarization falls to 37% of the original value; is dependent on the ratio of membrane resistance (r_m) to internal resistance (r_i)

the resistance to electrical current flowing longidudinally down the cable or neurite

the resistance to electrical current flow across a membrane

a form of synaptic inhibition in which the main effect is to reduce membrane reisistance, thereby shunting depolarizing current generated at excitatory synapses

a term used to describe the actions of neurotransmitters that do not directly evoke postsynaptic potentials but modify the cellular response to excitatory postsynaptic potentials and inhibitory postsynaptic potentials generated by other synpases

a catecholamine neurotransmitter synthesized from dopamine, also called noradrenaline

an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), a second messenger

a second messenger formed frome adenosine triphosphate (ATP) by the action of the enzyme adenylyl cyclase

a class of enzymes that phosphorylate proteins, a reation that changes the conformation of the protein and its biological activity

a biochemical reaction in which a phosphate group (PO₄^2-) is transferred from adenosine triphosphate (ATP) to another molecule, when this is done to proteins by protein kinases thier biological activity is changed