Allopregnanolone Improves Locomotor Activity and Arousal in the Aged CGG Knock-in Mouse Model of Fragile X-Associated Tremor/Ataxia Syndrome

Carriers of the fragile X premutation (PM) can develop a variety of early neurological symptoms, including depression, anxiety and cognitive impairment as well as being at risk for developing the late-onset fragile X-associated tremor/ataxia syndrome (FXTAS). The absence of effective treatments for FXTAS underscores the importance of developing efficacious therapies to reduce the neurological symptoms in elderly PM carriers and FXTAS patients. A recent preliminary study reported that weekly infusions of Allopregnanolone (Allop) may improve deficits in executive function, learning and memory in FXTAS patients. Based on this study we examined whether Allop would improve neurological function in the aged CGG knock-in (CGG KI) dutch mouse, B6.129P2(Cg)-Fmr1tm2Cgr/Cgr, that models much of the symptomatology in PM carriers and FXTAS patients. Wild type and CGG KI mice received 10 weekly injections of Allop (10 mg/kg, s.c.), followed by a battery of behavioral tests of motor function, anxiety, and repetitive behavior, and 5-bromo-2′-deoxyuridine (BrdU) labeling to examine adult neurogenesis. The results provided evidence that Allop in CGG KI mice normalized motor performance and reduced thigmotaxis in the open field, normalized repetitive digging behavior in the marble burying test, but did not appear to increase adult neurogenesis in the hippocampus. Considered together, these results support further examination of Allop as a therapeutic strategy in patients with FXTAS.

Comparative analysis of morphospace of Neotropical Sericini (Coleoptera: Scarabaeidae): disparity in the light of species diversity and activity patterns

The striking diversity among herbivorous Scarabaeoidea is still poorly understood. Therefore, we compare in these work linear measurements of body features of Neotropical and Old World linages of Sericini chafers to uncover patterns possibly linked to foraging behavior (day or night activity) or to the success of their diversification in terms of diversity. If diversity in Sericini chafers would be linked to morphological disparity, we would expect in the much less diverse Neotropical lineage a very clear drop of morphological disparity. Comparing the two major sister clades, Old World and Neotropical Sericini, in terms of their disparity and diversity, the here elaborated distance data do not support the hypothesis that morphological disparity could be a driver for the diversity of Sericini in the Old World. The influence of the metacoxal length on morphological disparity appears to represent a possible key for a better understanding of the evolution of Sericini in the Neotropical region (including their lower diversity) and answers the question of why they are so much less diverse than their sister lineage in the Old World. The increasing length of the metacoxal plate appears to be a result of the presence of a secondary metacoxal joint in Old World Sericini, which has a crucial impact on hind leg mobility and digging behavior. General body shape and single morphological characters appear under similar general evolutionary pressure: high morphometric disparity between nocturnal and diurnal Neotropical species was also corroborated by disparity estimated from discrete morphological characters.

Reforestation provides a foraging habitat for brown bears by increasing cicada density in the Shiretoko World Heritage site

Reforestation, which converts abandoned farmland back into forestland by planting woody species, can provide habitat for wildlife, including the brown bear (Ursus arctos Linnaeus, 1758). In the Shiretoko World Heritage site, northern Japan, where brown bears occur at high density, conifers have been planted since the 1970s to reforest abandoned farmland. In this area, brown bears were first observed digging for cicada nymphs (Lyristes bihamatus Motschulsky, 1861) from 2000. Our preliminary observations suggested the emergence of digging behavior might be associated with reforestation. We examined whether reforestation provided a foraging habitat for brown bears. We found that digging occurred only within the restored conifer forests, but not within the natural forest. The densities of cicada nymphs in the restored forests were higher than in the natural forest. These results indicate that the reforestation of abandoned farmland provides a foraging habitat for brown bears by increasing the availability of cicada nymphs in the Shiretoko World Heritage site.

Digging behavior discrimination test to probe burrowing and exploratory digging in male and female mice

Digging and burying behavior is often used to test anxiety and repetitive behaviors in mice. Different digging paradigms have been developed and have become popular assays for anxiety, obsessive-compulsive disorder (OCD), and repetitive behaviors in mouse models for multiple psychiatric and neurological conditions. However, the interpretation of these tests has been confounded by the difficulty of determining why mice dig. Digging is a naturalistic mouse behavior, that can be focused towards different goals, i.e. foraging for food, burrowing for shelter, burying objects, or even for recreation as has been shown for dogs, ferrets, and human children. Current testing protocols may focus on one type of digging (burrowing, foraging or burying) or allow the animal to dig freely, but interpretation of the results infers the motivation behind the behavior and often assumes that increased digging is a repetitive or compulsive behavior. We asked whether providing a choice between different types of digging activities would increase sensitivity to assess digging motivation. Here, we present a test to make clear determinations between burrowing and exploratory digging in mice. The test was designed to be rapid (less than 30 minutes) and using simple measures, so that it can be easily implemented with or without automated tracking. We found that mice seem to prefer burrowing when the option is available and asked whether food restriction would cause a switch from burrowing to exploration. While males and females displayed subtle behavioral differences at baseline that did not lead to statistically significant results, males readily switched from burrowing to digging outside, while females did not. In addition, when we tested a model of intellectual disability and autism spectrum disorder that had shown inconsistent results in the marble burying test, the Cc2d1a conditional knock-out mouse, we found greatly reduced burrowing only in males. Our findings indicate that digging is a nuanced behavior and suggest that male and female rodents may perform it differently. We propose that juxtaposing different kinds of digging will increase sensitivity in detecting deficits and will provide a better insight into behavioral differences.