Diminished Neurosteroid Sensitivity of Synaptic Inhibition and Altered Location of the  4 Subunit of GABAA Receptors in an Animal Model of Epilepsy

Background Although it does not suppress movement in response to noxious stimuli, the nonimmobilizer 1,2-dichlorohexafluorocyclobutane (F6, also known as 2N) does cause amnesia and seizures. These occur at 0.48 and 1.3 times, respectively, the concentrations that are predicted from its lipid solubility to cause immobility. The molecular and cellular basis of these effects is not known. The ionotropic gamma-aminobutyric acid type A (GABAA) receptor is modulated strongly by anesthetics, and it plays an important role in many seizure models. Also, the hippocampus is a structure central to the formation of memory and is susceptible to seizure generation. The authors therefore investigated the effect of F6 on GABAA receptor- mediated inhibition in hippocampal neurons. Methods Transverse hippocampal slices were prepared from young (12- to 21-day-old) Sprague-Dawley rats. Inhibitory postsynaptic currents were recorded from hippocampal CA1 pyramidal cells in the presence of ionotropic glutamate receptor antagonists. F6 was applied with the bath solution. The concentration of F6 achieved during the experiment at the location of synaptic inhibition was derived using a diffusion model. Results At tissue concentrations of up to 75 microm (approximately 5 x predicted minimal alveolar concentration), F6 had no discernible effect on either the amplitude or the kinetics of GABA-mediated synaptic currents. Isoflurane, by contrast, prolonged the decay time constant of these currents at 100 microm (approximately 0.3 x minimal alveolar concentration). Conclusions At concentrations that bracket the in vivo amnestic and seizure-inducing range, F6 has no discernible effect on fast synaptic GABAA receptors in hippocampal CA1 pyramidal neurons. Synaptic GABAA receptors sharply discriminate between volatile anesthetics and a prototype nonimmobilizer. Similar in vivo effects of anesthetics and nonimmobilizers may be mediated by different cellular mechanisms.

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Upregulation of extrasynaptic GABAA receptors and PSD-95 in the nucleus accumbens may be responsible for animal model of major depressive disorder

Neuroscience Research ◽

10.1016/j.neures.2011.07.1318 ◽

2011 ◽

Vol 71 ◽

pp. e302

Author(s):

Yoshio Iguchi ◽

Sakurako Kosugi ◽

Tetsu Hirosawa ◽

Yoshio Minabe ◽

Shigenobu Toda

Keyword(s):

Animal Model ◽

Major Depressive Disorder ◽

Nucleus Accumbens ◽

Depressive Disorder ◽

Gabaa Receptors ◽

Major Depressive

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Interferon-γ enhances neocortical synaptic inhibition by promoting membrane association and phosphorylation of GABAA receptors in a protein kinase C-dependent manner

Brain Behavior and Immunity ◽

10.1016/j.bbi.2022.01.001 ◽

2022 ◽

Author(s):

Gabriel M.S. Janach ◽

Maximilian Böhm ◽

Noah Döhne ◽

Ha-Rang Kim ◽

Marta Rosário ◽

...

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Gabaa Receptors ◽

Interferon Γ ◽

Membrane Association ◽

Synaptic Inhibition ◽

Dependent Manner ◽

Kinase C

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Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077086 ◽

1983 ◽

Vol 41 ◽

pp. 702-703

Author(s):

D. J. McComb ◽

J. Beri ◽

F. Zak ◽

K. Kovacs

Keyword(s):

Electron Microscopy ◽

Animal Model ◽

Epoxy Resin ◽

Immunoelectron Microscopy ◽

Tumor Type ◽

Gonadal Function ◽

Sprague Dawley ◽

Male And Female ◽

Reticulin Fibers ◽

Sprague Dawley Rats

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.

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