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Sharif, F.

Publications and source records attributed to Sharif, F..

3 recordsLinked to original sources
bioRxiv2024

Human brain changes after first psilocybin use

Psychedelics have robust effects on acute brain function and long-term behavior but whether they also cause enduring functional and anatomical brain changes is unknown. In a placebo-controlled, within-subjects, electroencephalography, and magnetic resonance imaging study in 28 healthy, entirely psychedelic-naive participants, anatomical and functional brain changes were detected from one-hour to one-month after a single high-dose (25 mg) of psilocybin. Increases in cognitive flexibility, psychological insight, and well-being were seen at one-month. Diffusion imaging done before and one-month after 25mg psilocybin revealed decreased axial diffusivity bilaterally in prefrontal-subcortical tracts that correlated with decreased brain network modularity over the same time period. Decreased modularity also correlated with improved well-being. Increased cortical signal entropy at 1- and 2-hours post-dosing predicted improved psychological well-being at one-month. Next-day psychological insight mediated the entropy to well-being relationship. All effects were exclusive to 25mg psilocybin; no effects occurred with a 1mg psilocybin placebo dose.

neuroscience↗
bioRxiv2020

Subcircuits of deep and superficial CA1 place cells support efficient spatial coding across heterogeneous environments

The hippocampus is thought to guide navigation by forming a cognitive map of space. However, the behavioral demands for such a map can vary depending on particular features of a given environment. For example, an environment rich in cues may require a finer resolution map than an open space. It is unclear how the hippocampal cognitive map adjusts to meet these distinct behavioral demands. To address this issue, we examined the spatial coding characteristics of hippocampal neurons in mice and rats navigating different environments. We found that CA1 place cells located in the superficial sublayer were more active in cue-poor environments, and preferentially used a firing rate code driven by intra-hippocampal inputs. In contrast, place cells located in the deep sublayer were more active in cue-rich environments and expressed a phase code driven by entorhinal inputs. Switching between these two spatial coding modes was supported by the interaction between excitatory gamma inputs and local inhibition.

neuroscience↗
bioRxiv2020

Evaluation of Antimicrobial, Antioxidant, Total Phenolic, Total Flavonoids, Metal Content and Proximate Potential of Solanum xanthocarpum L. (Solanaceae)

The current research work is focused on screening of antimicrobial, antioxidant, total phenolic, total flavonoid, metal estimation and proximate potential of four parts (fruits, leaves, stem bark and root bark) of S. xanthocarpum. Antimicrobial potential of dried crude extracts of S. xanthocarpum were evaluated against two gram positive bacteria (S. aureus, P. vulgaris), three gram negative bacteria (P. aeruginosa, K. pneumonia, E. coli), three fungi (A. flavus, F. solani, stolonifer) and two yeasts (S. cerevisiae, C. albicans) by using disc diffusion assay. Five organic solvents ranging from non-polar to highly polar were used for extraction of active metabolites. Amongst all the parts of S. xanthocarpum tested, antimicrobial activity of methanol extract of fruits (14.67{+/-}0.33) against P. aeruginosa, ethanolic extract of leaves against P. vulgaris (14{+/-}0.58), stem bark methanolic extract against S. aureus (13{+/-}0.58) and stem bark methanolic extract against P. vulgaris (17.67{+/-}0.33) were found to be more significant. All other extracts also showed promising antimicrobial activity against bacterial pathogens. Among fungal pathogens, R. stolonifer and S. cerevisiae were found to be more sensitive to extracts of S. xanthocarpum. Gram negative bacteria exhibited more resistance than gram positive bacteria. However, fungi were found to be more resistant than bacteria. All the extracts showed antioxidant activity. However, methanol extract of stem bark of S. xanthocarpum with IC50 value of 0.323102 mg mL-1 showed maximum antioxidant potential. Total phenolic contents ranged from 12.3541{+/-}1.73 to 23.2942{+/-}1.33 Pmol GA/ug. However, highest flavonoid content was found in the stem bark extract (17.8480{+/-}1.75 ugRutin/ug) and lowest in leaves extract of S. xanthocarpum (2.4806{+/-}0.59 ugRutin/ug). Total metal contamination in four parts of Solanum xanthocarpum (fruits, leaves, stem bark and root bark) was estimated by atomic absorption spectroscopy and results showed Cadmium contamination in its stem bark and root bark, Chromium contamination in leaves, stem bark and root bark, Copper and Magnesium contamination in all parts of S. xanthocarpum and Maganese contamination in leaves critically above the standard permissible limits. The proximate analysis of the Solanum xanthocarpum revealed that stem bark is a poor source of lipid (3.42%) and high carbohydrate (50.07%) and ash (16.50%) contents. Whereas, root bark has highest wet moisture content (65%), dry moisture content (20%) and lowest fiber (13%). Highest energy (285.455%), protein (8.32%), fat (9.79%) and lowest amount of ash (13%) was found in fruits. This composition shows that the Solanum xanthocarpum could be considered as a good source of carbohydrate, moisture and energy. These results revealed that over all, methanolic extract of the S. xanthocarpum is richest in phenolic, flavonoid and nutritional contents as well as most potent against bacterial and fungal pathogens. Therefore, further investigation is recommended to isolate, screen and characterize their active metabolites.

plant biology↗