Biomaterial Database

Intracellular recordings from ganglia of the thoracic sympathetic chain of the guinea-pig. 1969

J G Blackman, and R D Purves

1. Intracellular recordings have been obtained from cells of thoracic paravertebral sympathetic ganglia of guinea-pigs.2. Resting potentials were 50-70 mV. The steady-state current-voltage curve was linear for all hyperpolarizations and usually for depolarizations up to 10 mV. The slope of this curve was 19-186 MOmega (mean 55 MOmega). Time constants of cells were 6-14 msec (mean 9.1 msec).3. Most cells maintained a high rate of firing of action potentials during strong current pulses.4. Indirect stimulation via the rami communicantes or the interganglionic nerves of the sympathetic chain evoked a graded synaptic response which could lead to the discharge of one or more action potentials. Hexamethonium blocked the responses to such stimulation. Occasionally an all-or-none response remained, apparently conducted antidromically along the cell's axon.5. Spontaneous synaptic potentials were observed. Their occurrence frequency was increased during indirect stimulation. If they are assumed to represent single quanta of release of transmitter, the quantal content of a threshold synaptic potential was 8-20 quanta.6. Preganglionic fibres could ascend at least three segments or descend two after entering the sympathetic chain. They had conduction velocities of 0.1-1.1 m/sec.7. Inexcitable cells were frequently impaled. Repetitive indirect stimulation gave rise in these cells to a large (20 mV) slow depolarizing response.

UI	MeSH Term	Description	Entries
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005725	Ganglia, Autonomic	Clusters of neurons and their processes in the autonomic nervous system. In the autonomic ganglia, the preganglionic fibers from the central nervous system synapse onto the neurons whose axons are the postganglionic fibers innervating target organs. The ganglia also contain intrinsic neurons and supporting cells and preganglionic fibers passing through to other ganglia.	Autonomic Ganglia,Ganglion, Autonomic,Autonomic Ganglion
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D006584	Hexamethonium Compounds	Compounds containing the hexamethylenebis(trimethylammonium) cation. Members of this group frequently act as antihypertensive agents and selective ganglionic blocking agents.	Compounds, Hexamethonium
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
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
D013904	Thoracic Vertebrae	A group of twelve VERTEBRAE connected to the ribs that support the upper trunk region.	Vertebrae, Thoracic
D014403	Tubocurarine	A neuromuscular blocker and active ingredient in CURARE; plant based alkaloid of Menispermaceae.	Tubocurare,Tubocurarine Chloride,d-Tubocurare,d-Tubocurarine
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In