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1.
J Neurosci ; 44(22)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38627090

RESUMO

Humans have the remarkable ability to vividly retrieve sensory details of past events. According to the theory of sensory reinstatement, during remembering, brain regions specialized for processing specific sensory stimuli are reactivated to support content-specific retrieval. Recently, several studies have emphasized transformations in the spatial organization of these reinstated activity patterns. Specifically, studies of scene stimuli suggest a clear anterior shift in the location of retrieval activations compared with the activity observed during perception. However, it is not clear that such transformations occur universally, with inconsistent evidence for other important stimulus categories, particularly faces. One challenge in addressing this question is the careful delineation of face-selective cortices, which are interdigitated with other selective regions, in configurations that spatially differ across individuals. Therefore, we conducted a multisession neuroimaging study to first carefully map individual participants' (nine males and seven females) face-selective regions within ventral temporal cortex (VTC), followed by a second session to examine the activity patterns within these regions during face memory encoding and retrieval. While face-selective regions were expectedly engaged during face perception at encoding, memory retrieval engagement exhibited a more selective and constricted reinstatement pattern within these regions, but did not show any consistent direction of spatial transformation (e.g., anteriorization). We also report on unique human intracranial recordings from VTC under the same experimental conditions. These findings highlight the importance of considering the complex configuration of category-selective cortex in elucidating principles shaping the neural transformations that occur from perception to memory.


Assuntos
Mapeamento Encefálico , Reconhecimento Facial , Imageamento por Ressonância Magnética , Lobo Temporal , Humanos , Masculino , Feminino , Lobo Temporal/fisiologia , Lobo Temporal/diagnóstico por imagem , Adulto , Reconhecimento Facial/fisiologia , Adulto Jovem , Memória/fisiologia , Estimulação Luminosa/métodos , Rememoração Mental/fisiologia
2.
AACE Clin Case Rep ; 10(2): 55-59, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38523853

RESUMO

Background/Objective: Antineutrophil cytoplasmic antibody (ANCA) associated vasculitis is a rare small vessel vasculitis that can cause pituitary hypophysitis. Hypophysitis is difficult to treat, often requiring high doses of glucocorticoids with frequent flaring as glucocorticoids are tapered. We present a case of ANCA vasculitis involving the pituitary gland successfully treated with rituximab. Case Report: Fifty-one-year-old woman developed progressive frontal headaches, congestion, and epistaxis. Sinus computed tomography scan showed pituitary enlargement and chronic mucosal disease. Pituitary magnetic resonance imaging (MRI) confirmed a diffusely enlarged pituitary with a thickened pituitary stalk. Serologic evaluation revealed elevated inflammatory markers, positive perinuclear ANCA (p-ANCA), and an elevated serum anti-proteinase 3 (anti-PR3) antibody. The patient underwent pituitary biopsy, which showed adenohypophysitis with dense lymphoplasmacytic infiltration, some arranged perivascularly, compatible with involvement of the pituitary gland by ANCA vasculitis. The patient began rituximab and reported resolution of daily headaches, congestion, and epistaxis. Pituitary MRI scan 6 months after rituximab showed reduction in pituitary gland size and stalk thickening. Discussion: ANCA vasculitis is a rare etiology of pituitary hypophysitis, which can present a diagnostic and therapeutic challenge. Pituitary involvement of ANCA vasculitis can be identified through p-ANCA or cytoplasmic ANCA (c-ANCA) and biopsy of the involved tissue. Rituximab, a monoclonal antibody against CD20, has been successfully used to treat ANCA vasculitis and in this case, led to clinical improvements and reduction in the size of the pituitary gland. Conclusion: Pituitary biopsy enabled confirmation of ANCA hypophysitis and facilitated treatment with a steroid-sparing agent.

3.
bioRxiv ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38798494

RESUMO

Minimally invasive, high-bandwidth brain-computer-interface (BCI) devices can revolutionize human applications. With orders-of-magnitude improvements in volumetric efficiency over other BCI technologies, we developed a 50-µm-thick, mechanically flexible micro-electrocorticography (µECoG) BCI, integrating 256×256 electrodes, signal processing, data telemetry, and wireless powering on a single complementary metal-oxide-semiconductor (CMOS) substrate containing 65,536 recording and 16,384 stimulation channels, from which we can simultaneously record up to 1024 channels at a given time. Fully implanted below the dura, our chip is wirelessly powered, communicating bi-directionally with an external relay station outside the body. We demonstrated chronic, reliable recordings for up to two weeks in pigs and up to two months in behaving non-human primates from somatosensory, motor, and visual cortices, decoding brain signals at high spatiotemporal resolution.

4.
Front Neurol ; 14: 1331194, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38274865

RESUMO

Epilepsy is a chronic neurological disorder characterized by recurrent seizures, and is often comorbid with other neurological and neurodegenerative diseases, such as Alzheimer's disease (AD). Patients with recurrent seizures often present with cognitive impairment. However, it is unclear how seizures, even when infrequent, produce long-lasting deficits in cognition. One mechanism may be seizure-induced expression of ΔFosB, a long-lived transcription factor that persistently regulates expression of plasticity-related genes and drives cognitive dysfunction. We previously found that, compared with cognitively-intact subjects, the activity-dependent expression of ΔFosB in the hippocampal dentate gyrus (DG) was increased in individuals with mild cognitive impairment (MCI) and in individuals with AD. In MCI patients, higher ΔFosB expression corresponded to lower Mini-Mental State Examination scores. Surgically resected DG tissue from patients with temporal lobe epilepsy also showed robust ΔFosB expression; however, it is unclear whether ΔFosB expression also corresponds to cognitive dysfunction in non-AD-related epilepsy. To test whether DG ΔFosB expression is indicative of cognitive impairment in epilepsies with different etiologies, we assessed ΔFosB expression in surgically-resected hippocampal tissue from 33 patients with childhood epilepsies who had undergone Wechsler Intelligence Scale for Children (WISC) testing prior to surgery. We found that ΔFosB expression is inversely correlated with Full-Scale Intelligence Quotient (FSIQ) in patients with mild to severe intellectual disability (FSIQ < 85). Our data indicate that ΔFosB expression corresponds to cognitive impairment in epilepsies with different etiologies, supporting the hypothesis that ΔFosB may epigenetically regulate gene expression and impair cognition across a wide range of epilepsy syndromes.

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