OMP gene deletion results in an alteration in odorant quality perception.

To test the hypothesis that odorant quality perception is altered in olfactory marker protein (OMP)-null mice, we trained and tested adult OMP-null and control mice, using a 5-odorant identification confusion matrix task (animal odorant confusion matrix [AOCM]). On average, control and null mice performed the task at equivalent levels. The composite 5?×?5 response matrix from 40 testing sessions for each subject (both OMP-null and control) was compared with that of every other subject, yielding a dissimilarity matrix of AOCM responses. A multidimensional scaling (MDS) analysis of the dissimilarity data yielded a 4-dimensional solution, with each mouse occupying a point in MDS animal space. Statistical analysis demonstrated significant effects of genotype in determining the location of a mouse in the MDS space. These data suggest, therefore, that compared with that of controls, odorant quality perception is altered in the OMP-null mouse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Odorant identification and quality perception following methyl bromide-induced lesions of the olfactory epithelium.

Using a 5-odorant identification confusion matrix task, the authors assessed the consequence of olfactory epithelial damage on odorant quality perception in the rat. After establishing prelesion identification performance, each rat's epithelium was subjected to 330 ppm methyl bromide gas for 6 hr. Comparison of prelesion and 3-day postlesion performance demonstrated a significant decrease in identification as a consequence of 95%-98% epithelial destruction. Further, there was a differential effect of lesion on the ability of different animals to identify the different individual odorants. Evaluation of the anatomical state of the epithelium relative to performance on the identification task demonstrated a significant relationship between the extent and location of anatomical sparing and changes in individual odorant identifications. Assessment of pre- and postlesion quality perception for the individual rats demonstrated a highly significant shift in quality perception that was independent of any decrease in performance. These results provide strong support for the proposition that the regional variations in mucosal sensitivities within and across olfactory receptor gene expression zones are fundamentally important for the encoding of odorant quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does age make a difference? Predicting physical activity of South Koreans.

Social cognition models of health behavior are commonly understood as being universal, which implies that they are applicable to groups varying in age or cultural background, for example. Cultural uniqueness and characteristics of life-span development, however, necessitate the study of differential effects. Accordingly, the health action process approach (HAPA) was examined in younger and middle-aged/older adults from South Korea (N = 697) who participated in a longitudinal health screening study with a 6-month time lag. The HAPA model had a good fit within the middle-aged/older adult sample. Physical activity was predicted by planning, coping self-efficacy, and intention, which were, in turn, predicted by action self-efficacy, outcome expectancies, and risk perceptions. Conversely, the results indicated a poor model fit in the younger adult sample. The results suggest a different motivation for the involvement in physical activity as a function of age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reactivation of hippocampal ensemble activity patterns in the aging rat.

In young rats, the pattern of neuronal ensemble activity correlations expressed among hippocampal pyramidal cells during behavior persists during subsequent quiet wakefulness and slow-wave sleep, a process that may facilitate the consolidation of episodic memories. The present study explored the hypothesis that age-related changes in this process might contribute to memory impairments observed during normal aging. Neuronal activity was recorded from CA1 pyramidal cells, and in both young and old rats, there was a strong similarity between the resting epoch activity patterns and those from the preceding behavior epoch. This similarity was strongest during sharp-wave events. There were no detectable differences in the reactivation process or the decay rate between the young and old age groups. Thus, age differences in spatial memory do not appear to be explainable by differences in the spontaneous reactivation of familiar patterns within the hippocampus during the immediate postbehavior period. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contrasting activity patterns of two related octopus species, Octopus macropus and Octopus vulgaris.

Octopus macropus and Octopus vulgaris have overlapping habitats and are exposed to similar temporal changes. Whereas the former species is described as nocturnal in the field, there are conflicting reports about the activity time of the latter one. To compare activity patterns, the authors tested both species in the laboratory. Octopuses were exposed to a light-dark cycle and held under constant dim light for 7 days each. O. macropus showed nocturnal and light-cued activity. According to casual observations, O. vulgaris started out nocturnal but had switched to mostly diurnal when the experiment began. Individual variation of its activity was found. The different activity patterns of O. macropus and O. vulgaris might reflect their lifestyles, the latter species being more generalist. (PsycINFO Database Record (c) 2010 APA, all rights reserved)