Alex Martin

National Institute of Mental Health

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Dennis L. Murphy

Nassau University Medical Center

Trey Sunderland

University of British Columbia

Adrian W. Gilmore

National Institute of Mental Health

Stephen J. Gotts

National Institute of Mental Health

Brittany M. Mathes

McLean Hospital

Norman B. Schmidt

Florida State University

Melvyn P. Heyes

National Institute of Mental Health

Cheri L. Wiggs

National Institutes of Health

Anna M. Agron

National Institute of Mental Health

Peter A. Bandettini

National Institutes of Health

Cooperative Institutions

National Institute of Mental Health

National Institutes of Health

Florida State University

Harvard University

National Institute of Neurological Disorders and Stroke

Uniformed Services University of the Health Sciences

Johns Hopkins University

Henry M. Jackson Foundation

Hospital de Cruces

University of Pittsburgh

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Quinolinic acid in cerebrospinal fluid and serum in HIV‐1 Infection: Relationship to clinical and neurological status

Annals of Neurology (1991)

Melvyn P. Heyes Bruce J. Brew Alex Martin Richard W. Price Andres Μ. Salazar

Abstract Quinolinic acid is an “excitotoxic” metabolite and an agonist of N ‐methyl‐ D ‐aspartate receptors. Of patients infected with human immunodeficiency virus type 1 (HIV‐1) who were neurologically normal or exhibited only equivocal and subclinical signs of the acquired immunodeficiency syndrome (AIDS) dementia complex, concentrations of quinolinic acid in cerebrospinal fluid (CSF) were increased twofold in patients in the early stages of disease (Walter Reed stages 1 and 2) and averaged 3.8 times above normal in later‐stage patients (Walter Reed stages 4 through 6). However, in patients with either clinically overt AIDS dementia complex, aseptic meningitis, opportunistic infections, or neoplasms, CSF levels were elevated over 20‐fold and generally paralleled the severity of cognitive and motor dysfunction. CSF concentrations of quinolinic acid were significantly correlated to the severity of the neuropsychological deficits. After treatment of AIDS dementia complex with zidovudine and treatment of the opportunistic infections with specific antimicrobial therapies, CSF levels of quinolinic acid decreased in parallel with clinical neurological improvement. By analysis of the relationship between levels of quinolinic acid in the CSF and serum and integrity of the blood‐brain barrier, as measured by the CSF: serum albumin ratio, it appears that CSF levels of quinolinic acid may be derived predominantly from intracerebral sources and perhaps from the serum. While quinolinic acid may be another “marker” of host‐ and virus‐mediated events in the brain, the established excitotoxic effects of quinolinic acid and the magnitude of the increases in CSF levels of the acid raise the possibility that quinolinic acid plays a direct role in the pathogenesis of brain dysfunction associated with HIV‐1 infection.

Aseptic meningitis

10.1002/ana.410290215

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Citations (563)

Neural systems supporting lexical search guided by letter and semantic category cues: A self-paced overt response fMRI study of verbal fluency

NeuroImage (2009)

Rasmus M. Birn Lauren Kenworthy Laura K. Case Rachel A. Caravella Tyler B. Jones

Verbal fluency test

Cued speech

Frontal lobe

10.1016/j.neuroimage.2009.07.036

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Citations (357)

A longitudinal investigation of the association between rumination, hostility, and PTSD symptoms among trauma-exposed individuals

Journal of Affective Disorders (2020)

Brittany M. Mathes Grace Kennedy Danielle M. Morabito Alex Martin Carter E. Bedford

Hostility

Association (psychology)

10.1016/j.jad.2020.08.029

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Citations (22)

A comparison of single and multi-echo processing of fMRI data during overt autobiographical recall

bioRxiv (Cold Spring Harbor Laboratory) (2021)

Adrian W. Gilmore Anna M. Agron Estefanía I. González-Araya Stephen J. Gotts Alex Martin

ABSTRACT Recent years have seen an increase in the use of multi-echo fMRI designs by cognitive neuroscientists. Acquiring multiple echoes allows one to reduce thermal noise and identify nuisance signal components in BOLD data (Kundu et al., 2012). At the same time, multi-echo acquisitions increase data processing complexity and may incur a cost to the temporal and spatial resolution of the acquired data. Here, we re-examine a multi-echo dataset (Gilmore et al., 2021a) analyzed using multi-echo ICA (ME-ICA) and focused on hippocampal activity during the overly spoken recall of recent and remote autobiographical memories. The goal of the present series of analyses was to determine if ME-ICA’s theoretical denoising benefits might lead to a practical difference in the overall conclusions reached. Compared to single echo data, ME-ICA led to qualitatively different conclusions regarding hippocampal contributions to autobiographical recall: whereas the single echo analysis largely failed to reveal hippocampal activity relative to an active baseline, ME-ICA results supported predictions of the Standard Model of Consolidation and a time limited hippocampal involvement (Alvarez and Squire, 1994). These data provide a practical example of the benefits multi-echo denoising in a naturalistic memory paradigm and demonstrate how they can be used to address long-standing theoretical questions.

Echo (communications protocol)

Autobiographical Memory

10.1101/2021.11.03.467128

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A role for the anterior hippocampus in autobiographical memory construction regardless of temporal distance

bioRxiv (Cold Spring Harbor Laboratory) (2022)

Sam Audrain Adrian W. Gilmore Jenna M. Wilson Daniel L. Schacter Alex Martin

Abstract Mounting evidence suggests distinct functional contributions of the anterior and posterior hippocampus to autobiographical memory retrieval, but how these subregions function under different retrieval demands as memories age is not yet understood. Specifically, autobiographical memory retrieval is not a homogenous process, rather, it is thought to consist of multiple stages: an early stage of memory construction and a later stage of detailed elaboration, which may differently engage the hippocampus over time. In the present study, we analyzed data from 40 participants who constructed and overtly elaborated upon recent and remote memories in response to picture cues in the fMRI scanner. We previously reported a temporal gradient in the posterior hippocampus during the elaboration period of autobiographical retrieval, with posterior hippocampal activation observed for recent but not remote timepoints. Here, we consider the previously unanalyzed construction stage of retrieval, where participants searched for and selected a memory. We found no evidence of a temporal gradient during memory construction, instead observing strong anterior hippocampus activity regardless of memory remoteness. Our findings suggest a unique contribution of the anterior hippocampus to the construction process of autobiographical retrieval over time. These findings highlight that retrieval processes, which have yet to be considered in current models of systems consolidation, offer novel insights to hippocampal subregion function over time.

Autobiographical Memory

Long-term memory

10.1101/2022.05.01.490212

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Citations (1)

Cerebrospinal Fluid Quinolinic Acid Concentrations are Increased in Acquired Immune Deficiency Syndrome

Advances in experimental medicine and biology (1991)

Melvyn P. Heyes Bruce J. Brew Alex Martin S. P. Markey Richard W. Price

Pallor

10.1007/978-1-4684-5952-4_94

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Citations (29)