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- Fiuza, Felipe P., et al.
(author)
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Aging Alters Daily and Regional Calretinin Neuronal Expression in the Rat Non-image Forming Visual Thalamus
- 2021
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In: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 13
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Journal article (peer-reviewed)abstract
- Aging affects the overall physiology, including the image-forming and non-image forming visual systems. Among the components of the latter, the thalamic retinorecipient inter-geniculate leaflet (IGL) and ventral lateral geniculate (vLGN) nucleus conveys light information to subcortical regions, adjusting visuomotor, and circadian functions. It is noteworthy that several visual related cells, such as neuronal subpopulations in the IGL and vLGN are neurochemically characterized by the presence of calcium binding proteins. Calretinin (CR), a representative of such proteins, denotes region-specificity in a temporal manner by variable day-night expression. In parallel, age-related brain dysfunction and neurodegeneration are associated with abnormal intracellular concentrations of calcium. Here, we investigated whether daily changes in the number of CR neurons are a feature of the aged IGL and vLGN in rats. To this end, we perfused rats, ranging from 3 to 24 months of age, within distinct phases of the day, namely zeitgeber times (ZTs). Then, we evaluated CR immunolabeling through design-based stereological cell estimation. We observed distinct daily rhythms of CR expression in the IGL and in both the retinorecipient (vLGNe) and non-retinorecipient (vLGNi) portions of the vLGN. In the ZT 6, the middle of the light phase, the CR cells are reduced with aging in the IGL and vLGNe. In the ZT 12, the transition between light to dark, an age-related CR loss was found in all nuclei. While CR expression predominates in specific spatial domains of vLGN, age-related changes appear not to be restricted at particular portions. No alterations were found in the dark/light transition or in the middle of the dark phase, ZTs 0, and 18, respectively. These results are relevant in the understanding of how aging shifts the phenotype of visual related cells at topographically organized channels of visuomotor and circadian processing.
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2. |
- Linhares, Sarah Sophia G., et al.
(author)
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Prenatal exposure to fluoxetine modulates emotionality and aversive memory in male and female rat offspring
- 2022
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In: Behavioural Pharmacology. - : Lippincott Williams & Wilkins. - 0955-8810 .- 1473-5849. ; 33:8, s. 575-588
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Journal article (peer-reviewed)abstract
- During pregnancy, women are prone to depression, for which selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine. are usually the first-line treatment. However, fluoxetine can cross the placental barrier and affect fetuses, causing changes in serotonin levels early in life. Long-term effects in the brain circuits that control cognitive and emotional behavior are related to early fluoxetine exposure during development. In this study, we aimed to investigate whether fluoxetine exposure (10 mg/kg/day) from the 13th gestational day (GD13) to GD21 may lead to behavioral emotional-cognitive changes in male and female rat offspring approximately 90 days postnatally (similar to PN90). We have analyzed the performance of individuals in the open field and in the plus-maze discriminative avoidance task, which assesses anxiety and learning/memory processing behaviors. We have found that prenatal (GD13-GD21) exposure to fluoxetine strengthened aversive memory and induced higher anxiety levels in males, and quick extinction of aversive memory in females. Taken together, these results suggest that early exposure to fluoxetine impairs the basal state of anxiety and the cognitive functions of rats during adulthood, which may be in a sex-specific manner because males appear more susceptible than females.
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