In vitro extracellular recording of spontaneous activity of the intergeniculate leaflet neurons

2004 ◽  
Vol 1015 (1-2) ◽  
pp. 82-86 ◽  
Author(s):  
Anna Blasiak ◽  
Marian H Lewandowski
Keyword(s):  
Spontaneous Activity ◽  
Extracellular Recording ◽  
Intergeniculate Leaflet

Excitatory synaptic actions between pairs of neighboring pyramidal tract cells in the motor cortex

1988 ◽  
Vol 59 (2) ◽  
pp. 636-647 ◽  
Author(s):  
Y. Kang ◽  
K. Endo ◽  
T. Araki
Keyword(s):  
Motor Cortex ◽  
Spontaneous Activity ◽  
Current Pulse ◽  
Pyramidal Tract ◽  
Surface Membrane ◽  
Extracellular Recording ◽  
Recording Electrode ◽  
Axon Collaterals ◽  
Pt Cell ◽  
Cathodal Current

1. By spike-triggered averaging, we documented recurrent individual excitatory postsynaptic potentials (EPSPs) produced in 33 pyramidal tract (PT) cells (target) by the activity of axon collaterals of neighboring single PT cells (reference) in the motor cortex of the cat. 2. The computer was triggered by the spontaneous activity of reference PT cells or by current pulses applied to reference PT cells through the extracellular recording electrode. 3. The threshold for direct activation of PT cells was less than 0.1 microA with an anodal current pulse and 0.2-0.3 microA with a cathodal current pulse. 4. Application of an anodal current pulse directly activated only a single reference PT cell, the surface membrane of which was presumably touched by and sucked with the extracellular recording electrode. 5. When a cathodal current pulse was used, simultaneous activation of neurons or axons other than the reference PT cell was checked by changing the stimulus parameters along the characteristic strength-duration curve for the reference PT cell and/or by comparing averaged EPSPs obtained by cathodal stimulation with those obtained from spontaneous spikes of the reference PT cell. 6. Recurrent individual EPSPs were produced in fast PT cells by activation of neighboring slow PT cells and also of neighboring fast PT cells. Some recurrent individual EPSPs were also observed in slow PT cells. 7. The mean latencies of recurrent individual EPSPs produced by the spontaneous activity of reference slow and fast PT cells were 1.61 (n = 12) and 1.12 ms (n = 8), respectively. Their amplitudes ranged between 30 and 390 microV (n = 33). The rise time observed in fast PT cells with activation of slow and fast PT cells ranged from 1.6 to 3.6 ms (n = 20) and from 0.8 to 1.9 ms (n = 10), respectively. 8. The average conduction velocity of axon collaterals of slow and fast PT cells was estimated to be as slow as that of unmyelinated fibers in the cat. 9. It is suggested that axon collaterals of slow PT cells synapse onto more distal dendrites of fast PT cells than axon collaterals of fast PT cells.

scholarly journals Oxytocin shapes spontaneous activity patterns in the developing visual cortex by activating somatostatin interneurons

2019 ◽  
Author(s):  
Paloma P Maldonado ◽  
Alvaro Nuno-Perez ◽  
Jan Kirchner ◽  
Elizabeth Hammock ◽  
Julijana Gjorgjieva ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Spontaneous Activity ◽  
Sensory Processing ◽  
Activity Patterns ◽  
Network Activity ◽  
Synaptic Connections ◽  
Pairwise Correlations ◽  
Early Brain Development

SummarySpontaneous network activity shapes emerging neuronal circuits during early brain development, however how neuromodulation influences this activity is not fully understood. Here, we report that the neuromodulator oxytocin powerfully shapes spontaneous activity patterns. In vivo, oxytocin strongly decreased the frequency and pairwise correlations of spontaneous activity events in visual cortex (V1), but not in somatosensory cortex (S1). This differential effect was a consequence of oxytocin only increasing inhibition in V1 and increasing both inhibition and excitation in S1. The increase in inhibition was mediated by the depolarization and increase in excitability of somatostatin+ (SST) interneurons specifically. Accordingly, silencing SST+ neurons pharmacogenetically fully blocked oxytocin’s effect on inhibition in vitro as well its effect on spontaneous activity patterns in vivo. Thus, oxytocin decreases the excitatory/inhibitory ratio and modulates specific features of V1 spontaneous activity patterns that are crucial for refining developing synaptic connections and sensory processing later in life.

Role of prostaglandins in contractile activity of the ampulla of the rabbit oviduct

1980 ◽  
Vol 238 (2) ◽  
pp. E157-E166 ◽  
Author(s):  
M. J. Harper ◽  
L. W. Coons ◽  
D. A. Radicke ◽  
B. J. Hodgson ◽  
G. Valenzuela
Keyword(s):  
Spontaneous Activity ◽  
Contractile Activity ◽  
Prostaglandin E ◽  
High Dose ◽  
Field Stimulation ◽  
Prostaglandin Synthetase ◽  
Response Curves ◽  
Normal Tissues

Contractile activity of the ampulla of rabbit oviducts removed 24 h after an ovulating injection was studied in vitro. Spontaneous activity, field-stimulated activity, and response to phenylephrine were studied in normal, reversed, and scraped (endosalpinx removed) sections of tissues in the presence or absence of inhibitors of prostaglandin synthetase (8 or 51 micrograms/ml indomethacin or 10 or 100 micrograms/ml 5,8,11,14-eicosatetraynoic acid (ETA)). The effects of in vivo treatment with 10 mg/kg of indomethacin on the same responses were examined. Scraped tissues produced more prostaglandin E and F (measured by radioimmunoassay) than did normal tissues, and this production was suppressed by 10 micrograms/ml of indomethacin or 100 micrograms/ml of ETA. Production of prostaglandin by normal tissues was not depressed by these compounds in vitro, but was significantly reduced by pretreatment of the animals with indomethacin in vivo. In the absence of the endosalpinx, the myosalpinx exhibited spontaneous activity and responded to field stimulation and phenylephrine. Scraped and reversed tissues, however, showed a faster decline in response to field stimulation than normal tissues, and this was due to the traumatization. By contrast, traumatization increased the sensitivity of the tissue to respond to phenylephrine. Inhibition of prostaglandin synthetase by low doses of indomethacin or ETA prevented desensitization of the tissue to field stimulation, but this desensitization was little affected by the higher doses of indomethacin in vitro or in vivo. ETA did not affect the phenylephrine dose-response curves and nor did 8 micrograms/ml of indomethacin, whereas the high dose was inhibitory. Spontaneous activity was only affected by the in vivo pretreatment with indomethacin, which prevented the decline in activity of scraped tissue with time.

Adrenergic potentiation on spontaneous activity of canine paranodal fibers

1984 ◽  
Vol 247 (3) ◽  
pp. H415-H421
Author(s):  
W. W. Tse
Keyword(s):  
Spontaneous Activity ◽  
Tricuspid Valve ◽  
Action Potentials ◽  
Smooth Transition ◽  
Convex Side ◽  
Av Node ◽  
Junctional Tachycardia ◽  
His Bundle ◽  
Spontaneous Rate

The present study, using in vitro preparations, was designed to determine the anatomic, histological, and automatic properties of canine paranodal fibers. This tissue, together with the atrioventricular (AV) node and His bundle, constituted the three major tissues in the AV junction. The fascicles of the paranodal fibers ran parallel and adjacent to the base of the septal cusp of the tricuspid valve. The distal end of the paranodal fibers joined the lower half of the compact AV node on its convex side. Paranodal fibers when isolated were able to initiate spontaneous activity. Action potentials of many of these fibers showed primary pacemaker characteristics, i.e., a prominent phase 4 depolarization and smooth transition from phases 4 to 0. In 14 preparations, epinephrine (2.0 micrograms injected into the tissue bath) potentiated spontaneous rates to 144 +/- 6.0 beats/min from 61 +/- 5.0, an increase of 136%. Also, under the influence of epinephrine, paranodal fibers consistently generated a spontaneous rate higher than that of the AV node or His bundle, whether they were functionally connected or separated. These findings provide a basis for explaining the junctional tachycardia that occurs under adrenergic influence and demonstrate the presence of three major automatic tissues: the paranodal fibers, AV node, and His bundle in the canine AV junction.

Diversity of neurogenic smooth muscle electrical rhythmicity in mouse proximal colon

2020 ◽  
Vol 318 (2) ◽  
pp. G244-G253 ◽  
Author(s):  
Nick J. Spencer ◽  
Lee Travis ◽  
Lukasz Wiklendt ◽  
Timothy J. Hibberd ◽  
Marcello Costa ◽  
...  
Keyword(s):  
Nervous System ◽  
Smooth Muscle ◽  
Enteric Nervous System ◽  
Extracellular Recording ◽  
Proximal Colon ◽  
Proximal Region ◽  
Muscle Membrane ◽  
Mouse Colon ◽  
Cross Correlation Analysis

The mechanisms underlying electrical rhythmicity in smooth muscle of the proximal colon are incompletely understood. Our aim was to identify patterns of electrical rhythmicity in smooth muscle of the proximal region of isolated whole mouse colon and characterize their mechanisms of origin. Two independent extracellular recording electrodes were used to record the patterns of electrical activity in smooth muscle of the proximal region of whole isolated mouse colon. Cross-correlation analysis was used to quantify spatial coordination of these electrical activities over increasing electrode separation distances. Four distinct neurogenic patterns of electrical rhythmicity were identified in smooth muscle of the proximal colon, three of which have not been identified and consisted of bursts of rhythmic action potentials at 1–2 Hz that were abolished by hexamethonium. These neurogenic patterns of electrical rhythmicity in smooth muscle were spatially and temporally synchronized over large separation distances (≥2 mm rosto-caudal axis). Myogenic slow waves could be recorded from the same preparations, but they showed poor spatial and temporal coordination over even short distances (≤1 mm rostro-caudal axis). It is not commonly thought that electrical rhythmicity in gastrointestinal smooth muscle is dependent upon the enteric nervous system. Here, we identified neurogenic patterns of electrical rhythmicity in smooth muscle of the proximal region of isolated mouse colon, which are dependent on synaptic transmission in the enteric nervous system. If the whole colon is studied in vitro, recordings can preserve novel neurogenic patterns of electrical rhythmicity in smooth muscle. NEW & NOTEWORTHY Previously, it has not often been thought that electrical rhythmicity in smooth muscle of the gastrointestinal tract is dependent upon the enteric nervous system. We identified patterns of electrical rhythmicity in smooth muscle of the mouse proximal colon that were abolished by hexamethonium and involved the temporal synchronization of smooth muscle membrane potential over large spatial fields. We reveal different patterns of electrical rhythmicity in colonic smooth muscle that are dependent on the ENS.

Model network architectures in vitro on extracellular recording systems using microcontact printing

2001 ◽  
Vol 117 (1-3) ◽  
pp. 281-283 ◽  
Author(s):  
C. Sprössler ◽  
M. Scholl ◽  
M.C. Denyer ◽  
M. Krause ◽  
K. Nakajima ◽  
...  
Keyword(s):  
Microcontact Printing ◽  
Extracellular Recording ◽  
Network Architectures ◽  
Model Network

In vitro diencephalic neuronal thermosensitivity in normotensive and hypertensive rats

1989 ◽  
Vol 256 (2) ◽  
pp. R560-R566
Author(s):  
K. A. Travis ◽  
J. A. Boulant
Keyword(s):  
Firing Rate ◽  
Spontaneous Activity ◽  
Tissue Temperature ◽  
Tissue Slices ◽  
Spontaneously Hypertensive ◽  
Dorsomedial Hypothalamus ◽  
Firing Rates ◽  
Wistar Kyoto ◽  
Morphological Differences

Because morphological differences exist in hypothalamic neurons from spontaneously hypertensive (SH) and normotensive Wistar-Kyoto (WKY) rats, the present study recorded neuronal spontaneous activity and thermosensitivity from diencephalic tissue slices of these two strains. With the use of extracellular recordings from horizontal tissue slices, neurons were characterized according to location, firing rate at 37 degrees C, and firing rate response to changes in local tissue temperature. Compared with WKY neurons, SH neurons had higher firing rates in the preoptic-anterior hypothalamus and lower firing rates in the dorsomedial hypothalamus. In addition, SH warm-sensitive neurons were less thermosensitive over the hyperthermic range (37-40 degrees C), and SH temperature-insensitive neurons had higher spontaneous firing rates. These differences in spontaneous activity and thermosensitivity provide a neuronal basis to explain the elevation of core temperature observed in SH rats.

Temperature sensitivity of neurons in slices of the rat PO/AH hypothalamic area: effect of calcium

1993 ◽  
Vol 264 (2) ◽  
pp. R440-R448 ◽  
Author(s):  
H. A. Schmid ◽  
F. K. Pierau
Keyword(s):  
Cerebrospinal Fluid ◽  
Firing Rate ◽  
Spontaneous Activity ◽  
Temperature Sensitivity ◽  
Calcium Concentration ◽  
Extracellular Recording ◽  
Hypothalamic Area ◽  
Temperature Coefficients ◽  
Artificial Cerebrospinal Fluid ◽  
Cold Sensitive

The temperature sensitivity of spontaneously active neurons in slices of the preoptic and anterior hypothalamic areas (PO/AH) of rats was assessed by extracellular recording during sinoidal temperature displacements. Classifying cells according to their temperature coefficients (TC, impulses.s-1.degree C-1) revealed that 48% of the 177 cells tested were warm sensitive, 5% were cold sensitive, and 47% were temperature insensitive. Increasing the calcium concentration ([Ca2+]) of the artificial cerebrospinal fluid (aCSF) from 0.9 to 1.5 mM Ca2+ decreased the firing rate (FR) and TC of PO/AH neurons. Decreasing extracellular [Ca2+], however, elicited concentration-dependent increases in both parameters. This means in physiological terms that the number and temperature sensitivity of PO/AH neurons is strongly dependent on the extracellular [Ca2+]. Furthermore, these results suggest that caution is warranted when comparing numbers and temperature sensitivities of PO/AH neurons. After blocking synaptic transmission by superfusing the slice with aCSF containing reduced [Ca2+] and elevated [Mg2+], 8 out of 35 neurons ceased their spontaneous activity within 6 min, and 27 remained spontaneously active in low [Ca2+]-high [Mg2+] solution, but displayed unstable spontaneous activity and temperature sensitivity. It is concluded that aCSF with reduced [Ca2+] and elevated [Mg2+] is not a suitable tool to discriminate between inherent and synaptically mediated thermosensitivity.

In vitro screening of silver nanoparticles and ionic silver using neural networks yields differential effects on spontaneous activity and pharmacological responses

Toxicology ◽  
2016 ◽  
Vol 355-356 ◽  
pp. 1-8 ◽  
Author(s):  
Jenna D. Strickland ◽  
William R. LeFew ◽  
James Crooks ◽  
Diana Hall ◽  
Jayna N.R. Ortenzio ◽  
...  
Keyword(s):  
Neural Networks ◽  
Silver Nanoparticles ◽  
Spontaneous Activity ◽  
In Vitro Screening ◽  
Differential Effects ◽  
Ionic Silver
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