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Goyal, K.

Publications and source records attributed to Goyal, K..

2 recordsLinked to original sources

Scene perception and visuospatial memory converge at the anterior edge of visually-responsive cortex

To fluidly engage with the world, our brains must simultaneously represent both the scene in front of us and our memory of the immediate surrounding environment (i.e., local visuospatial context). How does the brains functional architecture enable sensory and mnemonic representations to closely interface, while also avoiding sensory-mnemonic interference? Here, we asked this question using first-person, head-mounted virtual reality (VR) and fMRI. Using VR, human participants of both sexes learned a set of immersive, real-world visuospatial environments in which we systematically manipulated the extent of visuospatial context associated with a scene image in memory across three learning conditions, spanning from a single field-of-view to a city street. We used individualized, within-subject fMRI to determine which brain areas support memory of the visuospatial context associated with a scene during recall (Exp. 1) and recognition (Exp. 2). Across the whole brain, activity in three patches of cortex was modulated by the amount of known visuospatial context, each located immediately anterior to one of the three scene perception areas of high-level visual cortex. Individual subject analyses revealed that these anterior patches corresponded to three functionally-defined place memory areas, which selectively respond when visually recalling personally familiar places. In addition to showing activity levels that were modulated by the amount of visuospatial context, multivariate analyses showed that these anterior areas represented the identity of the specific environment being recalled. Together, these results suggest a convergence zone for scene perception and memory of the local visuospatial context at the anterior edge of high-level visual cortex. Significance statementAs we move through the world, the visual scene around us is integrated with our memory of the wider visuospatial context. Here, we sought to understand how the functional architecture of the brain enables coexisting representations of the current visual scene and memory of the surrounding environment. Using a combination of immersive virtual reality and fMRI, we show that memory of visuospatial context outside the current field-of-view is represented in a distinct set of brain areas immediately anterior and adjacent to the perceptually-oriented scene-selective areas of high-level visual cortex. This functional architecture would allow efficient interaction between immediately adjacent mnemonic and perceptual areas, while also minimizing mnemonic-perceptual interference.

neuroscience↗

Preclinical efficacy of bacosides-lauric acid nano-herbal formulation incomparison to rivastigmine for treatment of Alzheimer's disease

Despite decades of rigorous scientific endeavors for Alzheimers disease (AD) drug development, massive failures in clinical trials is continuously posing healthcare and societal burden. Currently recommended single targeted drugs including rivastigmine with limited bioavailability can alleviate AD symptoms only for a limited period of time but unable to reverse the disease progression. Recent evidences consider poly-pharmacological and multi-targeted agents aiming at amyloid and tau burden, neuroinflammation, neuroprotection and cognitive enhancement as potential treatment options. In this regard, bioactive herbal compounds with holistic action and minimal adversities have gained prominence, though lacunae in their scientific validation and limited bio-permeability to cross BBB represent major hurdles. Previously, we showed that lactoferrin conjugated PEG-S-S-PLA-PCL-OH efficaciously delivered herbal compounds to brain and such nano-herbal formulation of bacosides-lauric acid (BAN-LAN) attenuated neuronal damages induced by scopolamine in vitro. Here, we tested the preclinical potential of BAN-LAN in reversal of AD pathologies in 5XFAD transgenic mice. Our nano-herbal formulation substantially reduced amyloid burden by clearing A{beta} plaques in the hippocampus of 5XFAD mice and also attenuated a{beta}42 induced alterations in AD associated gene expression in hippocampal neurons in vitro. It showed neuroprotection by rescuing neuronal damage and promoting neurogenesis in the hippocampus of AD transgenic mice. Anti-neuroinflammatory properties were also exhibited by the formulation as evident from inhibition of hippocampal astrocytic and microglial activation in 5XFAD mice. BAN-LAN showed cognitive efficacy by restoring memory impairment in AD transgenic mice and effects were more pronounced than unconjugated natural form and rivastigmine. These findings suggest that BAN-LAN may serve as a promising therapeutic agent for AD with better brain penetration and targeting multiple AD pathways.

pharmacology and toxicology↗