Effect of anoxia on intracellular and extracellular potassium activity in hypoglossal neurons in vitro

1991 ◽  
Vol 66 (1) ◽  
pp. 103-111 ◽  
Author(s):  
C. Jiang ◽  
G. G. Haddad
Keyword(s):  
Brain Slice ◽  
Neuronal Response ◽  
Extracellular Potassium ◽  
Intracellular Recordings ◽  
High Concentration ◽  
Slice Preparation ◽  
Adult Rats ◽  
Short Period ◽  
Brain Slice Preparation

1. A brain slice preparation was used to study the hypoglossal (XII) neuronal response to anoxia. Both intra- and extracellular potassium activities (K+i,K+o) were measured by the use of ion-selective microelectrodes, and K+ flux was assessed by the use of pharmacologic blockers. 2. Extracellular recordings showed that a short period of anoxia (4 min) induced an increase in K+o of 26.4 +/- 7.5 mM (mean +/- SD, n = 20) in the XII nucleus of adult rats. 3. Intracellular recordings (n = 31) in XII neurons showed a substantial decrease in K+i during anoxia. Fourteen neurons were analyzed in detail and these showed that XII neurons depolarized to -25.3 +/- 7.7 mV, whereas K+i dropped from 93.6 +/- 14.9 to 32 +/- 9.0 mM. These results strongly suggested that K+ is lost from XII neurons during anoxia. 4. Although the extracellular space (ECS) shrank by approximately 50% during anoxia, the possibility that the increase in K+o and decrease in K+i were mainly caused by shrinkage of the ECS and swelling of intraneuronal space was excluded to a great degree because the changes in K+i and K+o during anoxia were relatively very large. 5. To study the mechanisms by which K+ is lost from XII neurons, we used several pharmacologic blockers. High concentration of ouabain (10 mM) and strophanthidin (80 microM) increased K+o from baseline (3-4 mM) to 40.9 +/- 2.5 mM (n = 6) but did not abolish an additional anoxia-induced increase in K+o, suggesting that mechanisms other than Na(+)-K(+)-adenosine triphosphatase inhibition were also responsible for the anoxia-induced K+ leakage.(ABSTRACT TRUNCATED AT 250 WORDS)

An in vitro brain slice preparation to study the pharmacology of central vestibular neurons

1987 ◽  
Vol 18 (3) ◽  
pp. 267-273 ◽  
Author(s):  
Michael R. Lewis ◽  
Joel P. Gallacher ◽  
Patricia Shinnick-Gallagher
Keyword(s):  
Brain Slice ◽  
Slice Preparation ◽  
Vestibular Neurons ◽  
Brain Slice Preparation

scholarly journals GnRH Neuron Firing and Response to GABA in Vitro Depend on Acute Brain Slice Thickness and Orientation

Endocrinology ◽  
2012 ◽  
Vol 153 (8) ◽  
pp. 3758-3769 ◽  
Author(s):  
Stephanie Constantin ◽  
Richard Piet ◽  
Karl Iremonger ◽  
Shel Hwa Yeo ◽  
Jenny Clarkson ◽  
...  
Keyword(s):  
Brain Slice ◽  
Gabab Receptor ◽  
Gabab Receptors ◽  
In Vivo Studies ◽  
Slice Thickness ◽  
Gnrh Neuron ◽  
Slice Preparation ◽  
Gnrh Neurons ◽  
Brain Slice Preparation

The GnRH neurons exhibit long dendrites and project to the median eminence. The aim of the present study was to generate an acute brain slice preparation that enabled recordings to be undertaken from GnRH neurons maintaining the full extent of their dendrites or axons. A thick, horizontal brain slice was developed, in which it was possible to record from the horizontally oriented GnRH neurons located in the anterior hypothalamic area (AHA). In vivo studies showed that the majority of AHA GnRH neurons projected outside the blood-brain barrier and expressed c-Fos at the time of the GnRH surge. On-cell recordings compared AHA GnRH neurons in the horizontal slice (AHAh) with AHA and preoptic area (POA) GnRH neurons in coronal slices [POA coronal (POAc) and AHA coronal (AHAc), respectively]. AHAh GnRH neurons exhibited tighter burst firing compared with other slice orientations. Although α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) excited GnRH neurons in all preparations, γ-aminobutyric acid (GABA) was excitatory in AHAc and POAc but inhibitory in AHAh slices. GABAA receptor postsynaptic currents were the same in AHAh and AHAc slices. Intriguingly, direct activation of GABAA or GABAB receptors respectively stimulated and inhibited GnRH neurons regardless of slice orientation. Subsequent experiments indicated that net GABA effects were determined by differences in the ratio of GABAA and GABAB receptor-mediated effects in “long” and “short” dendrites of GnRH neurons in the different slice orientations. These studies document a new brain slice preparation for recording from GnRH neurons with their extensive dendrites/axons and highlight the importance of GnRH neuron orientation relative to the angle of brain slicing in studying these neurons in vitro.

Timing of neuronal and glial ultrastructure disruption during brain slice preparation and recovery in vitro

2003 ◽  
Vol 465 (1) ◽  
pp. 90-103 ◽  
Author(s):  
John C. Fiala ◽  
Sergei A. Kirov ◽  
Marcia D. Feinberg ◽  
Lara J. Petrak ◽  
Priya George ◽  
...  
Keyword(s):  
Brain Slice ◽  
Slice Preparation ◽  
Brain Slice Preparation

ANG II AT1 receptors induce depolarization and inward current in rat median preoptic neurons in vitro

1998 ◽  
Vol 275 (2) ◽  
pp. R632-R639 ◽  
Author(s):  
Donglin Bai ◽  
Leo P. Renaud
Keyword(s):  
Brain Slice ◽  
Lucifer Yellow ◽  
Membrane Conductance ◽  
Inward Rectification ◽  
Ang Ii ◽  
Slice Preparation ◽  
Inward Currents ◽  
Whole Cell Recordings ◽  
Brain Slice Preparation

To examine ANG II receptors in rat median preoptic (MnPO) neurons, we used patch-clamp whole cell recordings in a parasagittal brain slice preparation. Lucifer yellow-filled neurons displayed a simple morphology with two to three aspiny dendrites. Bath-applied ANG II (1–2,000 nM for 30 s) induced a response in 37 of 70 cells. In current-clamp recordings, cells displayed a prolonged (10- to 30-min) depolarizing plateau with action potential discharges and an associated reduction in postburst afterhyperpolarization and spike frequency adaptation. In voltage-clamp recordings (holding potential −65 mV), cells displayed tetrodotoxin-resistant inward currents of 7.6 ± 1.9 ( n = 5), 9.9 ± 1.9 ( n = 9), and 9.2 ± 2.2 pA ( n = 6) at 10, 200, and 2,000 nM, respectively. Responses were blockable by pretreatment with losartan (2 μM; n = 6) but not by PD-123177 (20 μM; n = 3). Net ANG II-induced current revealed a 7.8 ± 0.9% reduction in membrane conductance, decreasing but not reversing at hyperpolarized levels. Neurons expressing a strong hyperpolarization-activated, time-independent inward rectification were more likely to respond to ANG II. There was no correlation between the response of a neuron to ANG II and its response to norepinephrine.

23. A new adult rat brain slice preparation for ex vivo NMR spectroscopy studies of stroke

1994 ◽  
Vol 52 (1) ◽  
pp. A11
Author(s):  
M.T. Espanol ◽  
L. Litt ◽  
L.-H. Chang ◽  
T.L. James ◽  
P.R. Weinstein ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Rat Brain ◽  
Brain Slice ◽  
Ex Vivo ◽  
Slice Preparation ◽  
Adult Rat ◽  
Adult Rat Brain ◽  
Spectroscopy Studies ◽  
Rat Brain Slice ◽  
Brain Slice Preparation

TMOD-31. AN ORGANOTYPIC TISSUE PLATFORM TO BRIDGE IN VITRO AND IN VIVO ASSAYS FOR BRAIN CANCER TREATMENT

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi222-vi222
Author(s):  
Breanna Mann ◽  
Noah Bell ◽  
Denise Dunn ◽  
Scott Floyd ◽  
Shawn Hingtgen ◽  
...  
Keyword(s):  
Cell Lines ◽  
Brain Cancer ◽  
Brain Slice ◽  
Brain Slices ◽  
In Vitro Assays ◽  
Preclinical Model ◽  
Short Period ◽  
The Brain

Abstract Brain cancers remain one of the greatest medical challenges. The lack of experimentally tractable models that recapitulate brain structure/function represents a major impediment. Platforms that enable functional testing in high-fidelity models are urgently needed to accelerate the identification and translation of therapies to improve outcomes for patients suffering from brain cancer. In vitro assays are often too simple and artificial while in vivo studies can be time-intensive and complicated. Our live, organotypic brain slice platform can be used to seed and grow brain cancer cell lines, allowing us to bridge the existing gap in models. These tumors can rapidly establish within the brain slice microenvironment, and morphologic features of the tumor can be seen within a short period of time. The growth, migration, and treatment dynamics of tumors seen on the slices recapitulate what is observed in vivo yet is missed by in vitro models. Additionally, the brain slice platform allows for the dual seeding of different cell lines to simulate characteristics of heterogeneous tumors. Furthermore, live brain slices with embedded tumor can be generated from tumor-bearing mice. This method allows us to quantify tumor burden more effectively and allows for treatment and retreatment of the slices to understand treatment response and resistance that may occur in vivo. This brain slice platform lays the groundwork for a new clinically relevant preclinical model which provides physiologically relevant answers in a short amount of time leading to an acceleration of therapeutic translation.

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