Biomaterial Database

Synaptic transmission without action potentials: input-output properties of a nonspiking presynaptic neuron. 1978

K Graubard

1. Input-output properties of the inhibitory synaptic connection between non-spiking neurons (EX1) and gastric mill (GM) neurons were examined in the stomatogastric ganglion of the spiny lobster, Panulirus interruptus. Current was injected into and the voltage was recorded during current injection, two independent microelectrodes were used. 2. The EX1-GM synaptic connection is a conductance-increase inhibitory type, with an input-output curve that resembles the curve for the squid giant synapse. There is a threshold level of depolarization for transmitter release from the presynaptic cell. Beyond that threshold, increasing presynaptic depolarization causes increasing postsynaptic hyperpolarization (and inhibition). 3. A long presynaptic current step always causes a postsynaptic response with an initial peak of hyperpolarization followed by a decay to a less hyperpolarized plateau level. The plateau level is maintained, in most cells, for the duration of the presynaptic depolarization even over long periods (30 s). 4. The peak, but not the plateau, part of the postsynaptic response is sensitive to the past history of the synaptic connection. If a large conditioning pulse is applied to the presynaptic cell causing a large postsynaptic hyperpolarization, then the postsynaptic response to a later presynaptic test depolarization will have a reduced peak, leaving the plateau component unchanged.

UI	MeSH Term	Description	Entries
D008121	Nephropidae	Family of large marine CRUSTACEA, in the order DECAPODA. These are called clawed lobsters because they bear pincers on the first three pairs of legs. The American lobster and Cape lobster in the genus Homarus are commonly used for food.	Clawed Lobsters,Homaridae,Homarus,Lobsters, Clawed,Clawed Lobster,Lobster, Clawed
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013569	Synapses	Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.	Synapse