The structure of affect is well represented as a circumplex. The results of a within-subject longitudinal study of self-reported mood indicate individual differences in the circumplex structure of affective experience. These differences can be captured by two constructs: valence focus and arousal focus. Valence focus is the degree to which individuals attend the hedonic component of their affective experience; arousal focus is the degree to which individuals attend the arousal component of their affective experience. In this study, differences in individuals' attention to the hedonic and arousal components of affective experience were related to observed correlations between specific affective elements, such as (a) ratings of anxious and depressed mood and (b) "Negative Affect" and "Positive Affect.

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The locomotion of Caenorhabditis elegans consists of forward crawling punctuated by spontaneous reversals. To better understand the important variables that affect locomotion, we have described in detail the locomotory behavior of C. elegans and identified a set of parameters that are sufficient to describe the animal's trajectory. A model of locomotion based on these parameters indicates that reversal frequency plays a central role in locomotion. We found that several variables such as humidity, gravidity, and mechanostimulation influence reversal frequency. Specifically, both gentle and harsh touch can transiently suppress reversal frequency. Thus, reversal behavior is a model for the integration of information from numerous modalities reflecting diverse aspects of the state of an organism.

Psychologists believe that anxiety and depression self-report scales tap distinct constructs. This assumption was tested by using confirmatory factor analysis on mood data from nonclinical samples (K. S. Dobson, 1985a; I. H. Gotlib, 1984; J. Tanaka-Matsumi & V.A. Kameoka, 1986) and a clinical sample (J. Mendels, N. Weinstein, & C. Cochrane, 1972). These analyses provide evidence that anxiety and depression self-report scales do not measure discriminant mood constructs and may therefore be better thought of as measures of general negative mood rather than as measures of anxiety and depression per se.

BackgroundThe Morris water maze task is a hippocampus-dependent learning and memory test that typically takes between 3 days to 2 weeks of training. This task is used to assess spatial learning and induces the expression of genes known to be crucial to learning and memory in the hippocampus. A major caveat in the protocol is the prolonged duration of training, and difficulty of assessing the time during training in which animals have learned the task. We introduce here a condensed version of the task that like traditional water maze tasks, creates lasting hippocampus-dependent spatial cognitive maps and elicits gene expression following learning.MethodsThis paradigm was designed for rats to quickly acquire a hippocampus-dependent spatial cognitive map and retain this memory for at least 24 hours. To accomplish this, we interspersed visible and hidden training trials, delivering them in a massed fashion so training takes a maximum of 15 minutes. Learning was assessed based on latencies to the platform during each training trial, as well as time spent in the goal quadrant during probe testing 30 minutes and 24 hours after training. Normal rats were compared to two impaired cohorts (rats with fimbria-fornix lesions and rats administered NMDA receptor antagonist (CPP)). To quantitate hippocampal expression of known learning genes, real-time polymerase chain reaction (RT-PCR) was performed on hippocampal cDNA.ResultsWe show that massed training using alternating visible and hidden training trials generates robust short-term working and long-term reference memories in rats. Like the traditional Morris water maze paradigm, this task requires proper hippocampal function, as rats with fimbria-fornix lesions and rats administered CPP fail to learn the spatial component of the task. Furthermore, training in this paradigm elicits hippocampal expression of genes upregulated following learning in a variety of spatial tasks: homer1a, cfos and zif268.ConclusionsWe introduce here a condensed version of the Morris water maze, which is like a traditional water maze paradigm, in that it is hippocampus-dependent, and elicits hippocampal expression of learning genes. However, this task is administered in 15 minutes and induces spatial memory for at least 24 hours.