Animal memory: rats can answer unexpected questions about past events

A new study has found that rats are able to answer, in a hippocampus-dependent manner, unexpected questions about whether they recently ate food or not. The results highlight potential shared mechanisms for remembering personal events in rats and humans, and offer new insights into the nature of animal memory.     

Environmental enrichment of laboratory rodents: the answer depends on the question

Efforts to refine the care and use of animals in research have been ongoing for many years and have led to general standardization of rodent models, particularly with regard to animal housing, genetics, and health status. Concurrently, numerous informal practices and recommendations have been promulgated with the laudable intent of promoting general animal wellbeing through so-called enrichment of the cage environment. However, the variety of housing conditions fostered by efforts at environmental enrichment (EE) complicates the goal of establishing standardized or even defined environments for laboratory rodents. Many studies over the years have sought to determine whether or how various enrichment strategies affect the behavior and physiology of laboratory rodents. The findings, conclusions, and interpretations of these studies are mixed, particularly with regard to their application across rodent species, strains, genders, and ages; whether or how they affect the animals and the science; and, in some cases, whether the effects are positive, negative, or neutral in terms of animal wellbeing. Crucial issues related to the application of EE in research settings include its poorly defined effect on the animals, the potential for increased variability in the data, poor definition across labs and in publications, and potential for animal or scientific harm. The complexities, uncertainties, interpretational conundrums, varying conclusions, and lack of consensus in the EE literature warrant careful assessment of the benefits and liabilities associated with implementing such interventions. Reliance on evidence, professional judgment, and performance standards are crucial in the development of EE strategies.     

Thioredoxin: an unexpected meeting place

For much of the latter part of the 20th century, photosynthesis research at Berkeley was dominated by Daniel Arnon and Melvin Calvin. In this article, I have briefly described how their contributions jointly provided the foundation for our work on thioredoxin and how important Andrew Benson was to this effort.     

Dormant spores receive an unexpected wake-up call

Germination of spores of Bacillus bacteria can be triggered by nutrients acting through receptors on the spore's inner membrane. Shah et al. (2008) now report that cell wall peptidoglycan fragments can also trigger spore germination by binding to an inner membrane-bound protein kinase.     

WNK1 is an unexpected autophagy inhibitor

Autophagy is a cellular degradation pathway that is essential to maintain cellular physiology, and deregulation of autophagy leads to multiple diseases in humans. In a recent study, we discovered that the protein kinase WNK1 (WNK lysine deficient protein kinase 1) is an inhibitor of autophagy. The loss of WNK1 increases both basal and starvation-induced autophagy. In addition, the depletion of WNK1 increases the activation of the class III phosphatidylinositol 3-kinase (PtdIns3K) complex, which is required to induce autophagy. Moreover, the loss of WNK1 increases the expression of ULK1 (unc-51 like kinase 1), which is upstream of the PtdIns3K complex. It also increases the pro-autophagic phosphorylation of ULK1 at Ser555 and the activation of AMPK (AMP-activated protein kinase), which is responsible for that phosphorylation. The inhibition of AMPK by compound C decreases the magnitude of autophagy induction following WNK1 loss; however, it does not prevent autophagy induction. We found that the UVRAG (UV radiation resistance associated gene), which is a component of the PtdIns3K, binds to the N-terminal region of WNK1. Moreover, WNK1 partially colocalizes with UVRAG and this colocalization decreases when autophagy is stimulated in cells. The loss of WNK1 also alters the cellular distribution of UVRAG. The depletion of the downstream target of WNK1, OXSR1/OSR1 (oxidative-stress responsive 1) has no effect on autophagy, whereas the depletion of its relative STK39/SPAK (serine/threonine kinase 39) induces autophagy under nutrient-rich and starved conditions.     

Wound sepsis after cholecystectomy: effect of incidental appendicectomy.

The records of a consecutive series of 224 patients were analysed to discover the effect of incidental appendicectomy on the wound sepsis rate after cholecystectomy. One hundred and five patients had had a cholecystectomy alone and 119 cholecystectomy with incidental appendicectomy. The incidence of wound sepsis in patients not given adequate antibiotic prophylaxis was significantly lower (16-1%) when cholecystectomy alone was carried out than when the appendix was removed as well (41-1%).     

Aspects of plant intelligence: an answer to Firn

In a recent 'Invited Review', I stated the case for plant intelligence, provided definitions and outlined some of the consequences, illustrating them with examples. A short critique of this concept by Firn is given in the preceding 'Viewpoint' and rebuttals of the criticisms it contains are presented in the present article. The importance of plant intelligence as an emergent property resulting from interactions and communication of the component tissues is re-stated. The contentions made by Firn that plants are collectives of physically joined organs but acting in relative isolation of each other is subject to critical analysis and found to be contradicted by much established literature. Viewing plants as expressing intelligent behaviour should lead to better understanding of their ecological success and indicate experiments to test the basic concept.