Diet-altered body temperature rhythms are associated with altered rhythms of clock gene expression in peripheral tissues in vivo.

Temperature rhythms can act as potent signals for the modulation of the amplitude and phase of clock gene expression in peripheral organs in vitro, but the relevance of the circadian rhythm of core body temperature (Tc) as a modulating signal in vivo has not yet been investigated. Using calorie restriction and cafeteria feeding, we induced a larger and a dampened Tc amplitude, respectively, in male Wistar rats, and investigated the circadian expression profile of the core clock genes Bmal1, Per2, Cry1, and Rev-erbα, the heat-responsive genes heat shock protein 90 (Hsp90) and cold-inducible RNA binding protein (Cirbp), and Pgc1α, Pparα/γ/δ, Glut1/4, and Chop10 in the liver, skeletal muscle, white adipose tissue (WAT), and adrenal glands. Diet-altered Tc rhythms differentially affected the profiles of clock genes, Hsp90, and Cirbp expression in peripheral tissues. Greater Tc amplitudes elicited by calorie restriction were associated with large amplitudes of Hsp90 and Cirbp expression in the liver and WAT, in which larger amplitudes of clock gene expression were also observed. The amplitudes of metabolic gene expression were greater in the WAT, but not in the liver, in calorie-restricted rats. Conversely, diet-altered Tc rhythms were not translated to distinct changes in the amplitude of Hsp90, Cirbp, or clock or metabolic genes in the skeletal muscle or adrenal glands. While it was not possible to disentangle the effects of diet and temperature in this model, taken together with previous in vitro studies, our study presents novel data consistent with the notion that the circadian Tc rhythm can modulate the amplitude of circadian gene expression in vivo. The different responses of Hsp90 and Cirbp in peripheral tissues may be linked to the tissue-specific responses of peripheral clocks to diet and/or body temperature rhythms, but the association with the amplitude of metabolic gene expression is limited to the WAT.

A Re-evaluation of the Anatomy of the Claustrum in Rodents and Primates-Analyzing the Effect of Pallial Expansion.

The components of the claustrum have been identified by gene expression in mice, but there is still uncertainty about the location of homologous components in primates. To aid interpretation of homologous elements between rodents and primates, we used a current understanding of pallial topology, species-specific telencephalic deformation, and gene expression data. In both rodents and primates, pallial areas maintain conserved topological relationships regardless of relative differences in pallial expansion. The components of the claustrum in primates can, therefore, be identified on the basis of their conserved topological relationships and patterns of gene expression. In rodents, a fairly straight telencephalic long axis runs between the early septopreoptic and amygdalar poles of the pallium. In primates, however, the remarkable dorsal pallial expansion causes this axis to be distorted to form a C shape. This has resulted in a number of errors in the interpretation of the location of claustral components. These errors are likely to have resulted from the unexpected topographical positioning of claustral components due to the bent telencephalic axis. We argue that, once the telencephalic distortion has been accounted for, both rodents and primates have homologous claustral components, and that the topological relationships of these components are conserved regardless of differences in the relative expansion of pallial areas.

Elongation of the CA1 field of the septal hippocampus in ungulates.

It is widely assumed that the hippocampal formation seen in laboratory rodents and in primates is typical of that seen in other mammals. We have tested this assumption by examining sections of brains of 56 mammals from 20 mammalian orders from images on the brainmuseum.org website. We found wide variation in the form of the hippocampal formation, the most extreme examples of which are seen in ungulates, which possess an unusual elongation of the distal CA1 of the septal hippocampus. This phenomenon has not previously been reported. In individual coronal sections of the brains of seven artiodactyl ungulates, the pyramidal layer of CA1 is four times as long as CA2 + CA3. In a perissodactyl ungulate (Burchell's zebra) the distal end of CA1 is so large that it forms a number of folds. A similar but less pronounced CA1 elongation was seen in the brains of 14 carnivores. A modest elongation of CA1 is also present in some other placental mammals, notably the elephant shrew, hyrax, capybara, beaver, and rabbit. The elongation was not present in brains of primates, marsupials, or monotremes. The distal part of CA1 has been shown to play a role in object integration into the spatial map. We hypothesize that the distal CA1 enlargement could serve to enhance the ability to integrate objects into spatial navigation, which would be an advantage for migrating herds of ungulates. We suggest that the remarkable elongation of Q5 CA1 represents a major evolutionary specialization in the ungulates.

Magnetic resonance studies of a redox probe in a reverse sodium bis(2-ethylhexyl)sulfosuccinate/octane/water microemulsion.

The location and dynamics of the [Ru(bpy)(3)](2+) complex inside sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/octane/water microemulsions were studied, over a range of droplet sizes, using magnetic resonance spectroscopy, dynamic light scattering, and molecular modeling. The T(1) magnetic resonance relaxation times of water inside the AOT reverse micelles (RMs) were measured in both the presence and the absence of the [Ru(bpy)(3)](2+) complex. Large size droplet RMs (ω(0) > 20) were found to be sensitive to the presence of the [Ru(bpy)(3)](2+) complex, which was detected through a decrease in the T(1) relaxation time of the water inside the RM core, as compared to RMs containing no [Ru(bpy)(3)](2+). However, no difference in T(1) relaxation time was observed for water in small RMs (ω(0) < 20). Two-dimensional (1)H-(1)H NOESY spectroscopy was performed to probe the location of the [Ru(bpy)(3)](2+) complex in both small (ω(0) = 9.2) and large droplets (ω(0) = 34.9). Cross-peaks between protons in the AOT tail groups and bipyridyl ligands were observed, showing that the [Ru(bpy)(3)](2+) complex resided in the RM interface. Finally, molecular modeling simulations were performed to probe the location of the [Ru(bpy)(3)](2+) complex and the structure of the RM. Molecular dynamics simulations confirmed the location of the [Ru(bpy)(3)](2+) complex in the RM interface and detected differences in the surfactant layer and the amount of water penetration into this layer with changing droplet size.