Previous studies have demonstrated that macromolecular synthesis in the brain is modulated in association with the occurrence of sleep and wakefulness. Similarly, the spectral composition of electroencephalographic activity that occurs during sleep is dependent on the duration of prior wakefulness. Since this homeostatic relationship between wake and sleep is highly conserved across mammalian species, genes that are truly involved in the electroencephalographic response to sleep deprivation (SD) might be expected to be conserved across mammalian species. Therefore, in the rat cerebral cortex, we have studied the effects of SD on the expression of immediate early gene (IEG) and heat shock protein (HSP) mRNAs previously shown to be upregulated in the mouse brain in SD and in recovery sleep (RS) after SD. We find that the molecular response to SD and RS in the brain is highly conserved between these two mammalian species, at least in terms of expression of IEG and HSP family members. Using Affymetrix Neurobiology U34 GeneChips ® , we also screened the rat cerebral cortex, basal forebrain, and hypothalamus for other genes whose expression may be modulated by SD or RS. We find that the response of the basal forebrain to SD is more similar to that of the cerebral cortex than to the hypothalamus. Together, these results suggest that sleep-dependent changes in gene expression in the cerebral cortex are similar across rodent species and therefore may underlie sleep historydependent changes in sleep electroencephalographic activity. KeywordsTaqman analysis; sleep deprivation; immediate early genes; basal forebrain; cerebral cortex; hypothalamus HHS Public Access Author Manuscript Author ManuscriptAuthor Manuscript Author ManuscriptSleep is a homeostatic process in that the time spent asleep and the continuity of sleep states are directly related to the duration of prior wakefulness. Although sleep duration and the time spent in each of its stages are parameters commonly measured in sleep studies, sleep also has an intensity dimension, measurable by slow wave activity (SWA) in the electroencephalogram (EEG) during non-rapid eye movement (NREM) sleep. The amplitude of EEG SWA is directly proportional to the duration of prior wake and consequently has been proposed as a marker for the homeostatic regulation of sleep in mammals (Borbely and Achermann, 2000). Accordingly, sleep need, measurable as EEG SWA once sleep is initiated, is thought to accrue during wakefulness. Conversely, the decline of EEG SWA amplitude across a sleep bout is thought to reflect the diminution of the sleep-dependent "Process S" that reflects recovery from prior waking activities.The temporal dynamics of the sleep-dependent discharge of sleep need (reflected in the decay of the sleep-dependent Process S) is conserved among genetically distinct rodent strains (Franken et al., 2001). The conserved nature of Process S supports the concept that EEG SWA may be an electrophysiological marker of restorative neurochemical processes that occur during...

Mosquito midgut plays a crucial role in its vector susceptibility and pathogen interaction. Identification of the sustainable microflora of the midgut environment can therefore help in evaluating its contribution in mosquito-pathogen interaction and in turn vector competence. To understand the bacterial diversity in the midgut of Aedes aegypti mosquitoes, we conducted a screening study of the gut microbes of these mosquitoes which were either collected from fields or reared in the laboratory “culture-dependent” approach. This work demonstrated that the microbial flora of larvae and adult Ae. aegypti midgut is complex and is dominated by Gram negative proteobacteria. Serratia odorifera was found to be stably associated in the midguts of field collected and laboratory reared larvae and adult females. The potential influence of this sustainable gut microbe on DENV-2 susceptibility of this vector was evaluated by co-feeding S. odorifera with DENV-2 to adult Ae. aegypti females (free of gut flora). The observations revealed that the viral susceptibility of these Aedes females enhanced significantly as compared to solely dengue-2 fed and another gut inhabitant, Microbacterium oxydans co-fed females. Based on the results of this study we proposed that the enhancement in the DENV-2 susceptibility of Ae. aegypti females was due to blocking of prohibitin molecule present on the midgut surface of these females by the polypeptide of gut inhabitant S. odorifera.

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