Biomaterial Database

Graded action potentials generated by differentiated human neuroblastoma cells. 1994

S Johansson

Department of Neurochemistry and Neurotoxicology, Stockholm University, Sweden.

Stimulus-dependent impulses and resting membrane parameters of human SH-SY5Y neuroblastoma cells, induced to differentiate by retinoic acid, were investigated with tight-seal recording techniques. Mean resting potential was -53 mV, mean input resistance 2.1 G omega, mean capacitance 14 pF, and mean time constant 30 ms. Rectangular current steps induced clearly stimulus-dependent impulses, with stronger current steps causing impulses of larger amplitude. The degree of impulse variability differed significantly among different cells. The current thresholds for impulse generation ranged from 35 to 100 pA for 10 ms current steps. With longer current steps, thresholds below 10 pA were recorded. In response to 0.5-1 s long current steps, most cells generated only a single impulse, but a few cells generated two impulses. When two impulses were generated, the interval between the impulses decreased with increasing stimulus strength. Whole-cell currents were recorded under voltage-clamp conditions. Voltage-activated, tetrodotoxin-sensitive Na+ currents and 'delayed rectifier' K+ currents were recorded. The degree of impulse variability was correlated to the maximum Na+ current density. Cells with large Na+ currents showed little impulse variability, while a marked variability was recorded in cells with intermediate or small Na+ currents. Cells which generated more than one impulse in response to prolonged stimuli belonged to the group with large Na+ currents. Spontaneous impulse-currents were recorded from cell-attached membrane patches on intact cells. Also these impulses showed a large variability in amplitude: In each of five cells analysed, the peak-to-peak amplitude varied by a factor larger than 1.7.

UI	MeSH Term	Description	Entries
D009447	Neuroblastoma	A common neoplasm of early childhood arising from neural crest cells in the sympathetic nervous system, and characterized by diverse clinical behavior, ranging from spontaneous remission to rapid metastatic progression and death. This tumor is the most common intraabdominal malignancy of childhood, but it may also arise from thorax, neck, or rarely occur in the central nervous system. Histologic features include uniform round cells with hyperchromatic nuclei arranged in nests and separated by fibrovascular septa. Neuroblastomas may be associated with the opsoclonus-myoclonus syndrome. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2099-2101; Curr Opin Oncol 1998 Jan;10(1):43-51)	Neuroblastomas
D001932	Brain Neoplasms	Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.	Brain Cancer,Brain Metastases,Brain Tumors,Cancer of Brain,Malignant Primary Brain Tumors,Neoplasms, Intracranial,Benign Neoplasms, Brain,Brain Neoplasm, Primary,Brain Neoplasms, Benign,Brain Neoplasms, Malignant,Brain Neoplasms, Malignant, Primary,Brain Neoplasms, Primary Malignant,Brain Tumor, Primary,Brain Tumor, Recurrent,Cancer of the Brain,Intracranial Neoplasms,Malignant Neoplasms, Brain,Malignant Primary Brain Neoplasms,Neoplasms, Brain,Neoplasms, Brain, Benign,Neoplasms, Brain, Malignant,Neoplasms, Brain, Primary,Primary Brain Neoplasms,Primary Malignant Brain Neoplasms,Primary Malignant Brain Tumors,Benign Brain Neoplasm,Benign Brain Neoplasms,Benign Neoplasm, Brain,Brain Benign Neoplasm,Brain Benign Neoplasms,Brain Cancers,Brain Malignant Neoplasm,Brain Malignant Neoplasms,Brain Metastase,Brain Neoplasm,Brain Neoplasm, Benign,Brain Neoplasm, Malignant,Brain Neoplasms, Primary,Brain Tumor,Brain Tumors, Recurrent,Cancer, Brain,Intracranial Neoplasm,Malignant Brain Neoplasm,Malignant Brain Neoplasms,Malignant Neoplasm, Brain,Neoplasm, Brain,Neoplasm, Intracranial,Primary Brain Neoplasm,Primary Brain Tumor,Primary Brain Tumors,Recurrent Brain Tumor,Recurrent Brain Tumors,Tumor, Brain
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.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D013779	Tetrodotoxin	An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.	Fugu Toxin,Tarichatoxin,Tetradotoxin,Toxin, Fugu
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D015222	Sodium Channels	Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.	Ion Channels, Sodium,Ion Channel, Sodium,Sodium Channel,Sodium Ion Channels,Channel, Sodium,Channel, Sodium Ion,Channels, Sodium,Channels, Sodium Ion,Sodium Ion Channel
D018408	Patch-Clamp Techniques	An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.	Patch Clamp Technique,Patch-Clamp Technic,Patch-Clamp Technique,Voltage-Clamp Technic,Voltage-Clamp Technique,Voltage-Clamp Techniques,Whole-Cell Recording,Patch-Clamp Technics,Voltage-Clamp Technics,Clamp Technique, Patch,Clamp Techniques, Patch,Patch Clamp Technic,Patch Clamp Technics,Patch Clamp Techniques,Recording, Whole-Cell,Recordings, Whole-Cell,Technic, Patch-Clamp,Technic, Voltage-Clamp,Technics, Patch-Clamp,Technics, Voltage-Clamp,Technique, Patch Clamp,Technique, Patch-Clamp,Technique, Voltage-Clamp,Techniques, Patch Clamp,Techniques, Patch-Clamp,Techniques, Voltage-Clamp,Voltage Clamp Technic,Voltage Clamp Technics,Voltage Clamp Technique,Voltage Clamp Techniques,Whole Cell Recording,Whole-Cell Recordings