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AbstractIn humans, traumatic brain injury (TBI) causes pathological changes in the hypothalamus (HT) and the pituitary. One consequence of TBI is hypopituitarism, with deficiency of single or multiple hormones of the anterior pituitary (AP), including growth hormone (GH). At present no animal model of TBI with ensuing hypopituitarism has been demonstrated. The main objective of this study was to investigate whether cortical contusion injury (CCI) could induce long-term reduction of serum GH in rats. We also tested the hypothesis that TBI to the medial frontal cortex (MFC) would induce inflammatory changes in the HT and AP. Methods:Nine young adult male rats were given sham surgery (n = 4) or controlled impact contusions (n = 5) of the MFC. Two months post-injury they were killed, trunk blood collected and their brains and AP harvested. GH was measured in serum and AP using ELISA and Western blot respectively. Interleukin-1β (IL-1β) and glial fibrillary acidic protein (GFAP) were measured in the cortex (Cx), HT, and AP by Western blot. Results:Lesion rats had significantly (p< 0.05) lower levels of GH in the AP and serum, unaltered serum IGF-1, and significantly (p< 0.05) higher levels of IL-1β in the Cx and HT and GFAP in the Cx, HT, and AP compared to that of shams. Conclusion:CCI leads to a long-term depletion of serum GH in male rats. This chronic change in GH post-TBI is probably the result of systemic and persistent inflammatory changes observed at the level of HT and AP, the mechanism of which is not yet known. [ABSTRACT FROM AUTHOR]

Surface chemistry and structural changes of a potassia promoted, chromia stabilised iron oxide catalyst were examined before and after the non oxidative dehydrogenation of ethylbenzene to styrene using x-ray photoelectron spectroscopy ( xps). xps binding energies of the Fe(2 p, 3 s, 3 p, 3 d), K(2 p, 3 s, 3 p), Cr(2 p, 3 s, 3 p) and O(1 s) levels along with characteristic shifts in the binding energies, spin-orbit splittings and satellite, multiplet splittings help in identifying surface active species such as FeO, FeO, FeOOH at the surface of fresh and used catalysts. [ABSTRACT FROM AUTHOR]

Circuit interactions within the medial entorhinal cortex (MEC) translate movement into a coherent code for spatial location. Entorhinal principal cells are subject to strong lateral inhibition, suggesting that a disinhibitory mechanism may drive their activation. Cortical Vasoactive Intestinal Peptide (VIP) expressing inhibitory neurons are known to contact other interneurons and excitatory cells and are thus capable of providing a local disinhibitory mechanism, yet little is known about this cell type in the MEC. To investigate the electrophysiological and morphological properties of VIP cells in the MEC, we use in vitro whole-cell patch-clamp recordings in VIPcre/tdTom mice. We report several gradients in electrophysiological properties of VIP cells that differ across laminae and along the dorsal-ventral MEC axis. We additionally show that VIP cells have distinct morphological features across laminae. Together, these results characterize the cellular and morphological properties of VIP cells in the MEC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Badrinarayanan, Manseau, Williams and Brandon.)

The nicotinic acetylcholine receptor alpha2 subunit (Chrna2) is a specific marker for oriens lacunosum-moleculare (OLM) interneurons in the dorsal CA1 region of the hippocampus. It was recently shown using a Chrna2-cre mice line that OLM interneurons can modulate entorhinal cortex and CA3 inputs and may therefore have an important role in gating, encoding, and recall of memory. In this study, we have used a combination of electrophysiology and optogenetics using Chrna2-cre mice to determine the role of Chrna2 interneurons in the subiculum area, the main output region of the hippocampus. We aimed to assess the similarities between Chrna2 subiculum and CA1 neurons in terms of the expression of interneuron markers, their membrane properties, and their inhibitory input to pyramidal neurons. We found that subiculum and CA1 dorsal Chrna2 cells similarly expressed the marker somatostatin and had comparable membrane and firing properties. The somas of Chrna2 cells in both regions were found in the deepest layer with axons projecting superficially. However, subiculum Chrna2 cells displayed more extensive projections with dendrites which occupied a significantly larger area than in CA1. The post-synaptic responses elicited by Chrna2 cells in pyramidal cells of both regions revealed comparable inhibitory responses elicited by GABA A receptors and, interestingly, GABA B receptor mediated components. This study provides the first in-depth characterization of Chrna2 cells in the subiculum, and suggests that subiculum and CA1 Chrna2 cells are generally similar and may play comparable roles in both sub-regions.

The total synthesis of both enantiomers of pestalospirane B, 2, has been achieved using a bioinspired tandem dimerization-spiroketalization reaction. Electronic circular dichroism (ECD) and X-ray analysis were used to revise the absolute stereochemistry of the natural product pestalospirane B from 3S, 3'S, 12R, 12'R to its enantiomer 3R, 3'R, 12S, 12'S.