Article
Gastroenterology & Hepatology
Maria Arnoriaga-Rodriguez, Jordi Mayneris-Perxachs, Oren Contreras-Rodriguez, Aurelijus Burokas, Juan-Antonio Ortega-Sanchez, Gerard Blasco, Claudia Coll, Carles Biarnes, Anna Castells-Nobau, Josep Puig, Josep Garre-Olmo, Rafel Ramos, Salvador Pedraza, Ramon Brugada, Joan C. Vilanova, Joaquin Serena, Jordi Barretina, Jordi Gich, Vicente Perez-Brocal, Andres Moya, Xavier Fernandez-Real, Lluis Ramio-Torrenta, Reinald Pamplona, Joaquim Sol, Mariona Jove, Wifredo Ricart, Manuel Portero-Otin, Rafael Maldonado, Jose Manuel Fernandez-Real
Summary: The study revealed the relationship between inhibitory control and obesity, as well as the interactions between gut microbiota, metabolomics, and brain structure. Metabolic pathway alterations associated with obesity were found to be linked to inhibitory control, and results were validated in mice through fecal microbiota transplantation.
Article
Psychology, Clinical
Julius Steding, Franziska Ritschel, Ilka Boehm, Daniel Geisler, Joseph A. King, Veit Roessner, Michael N. Smolka, Florian Daniel Zepf, Stefan Ehrlich
Summary: This study investigated the neural responses related to reward processing in individuals with a history of anorexia nervosa (recAN) during acute tryptophan depletion (ATD). The results suggested a normalization of reward-related neural responses in recAN during ATD.
PSYCHOLOGICAL MEDICINE
(2023)
Review
Physiology
D. E. Alcantara-Zapata, N. Lucero, N. De Gregorio, P. Astudillo Cornejo, C. Ibarra Villanueva, M. J. Baltodano-Calle, G. F. Gonzales, C. Behn
Summary: Sexual (and gender)-dimorphism in tolerance to hypobaric hypoxia has become increasingly important for monitoring human activities at high altitudes. The prevalence of anxiety and depression in women is already double than that of men at low altitudes, and it is expected to increase even more at high altitudes. This study explores the potential involvement of the tryptophan-melatonin axis in mood changes caused by exposure to hypobaric hypoxia, highlighting the anxiogenic effects of high altitude exposure. The study suggests that sex-related differences in neural network organization and hormonal changes, as well as the overexpression effects of a 5-HT transporter protein, may contribute to mood alterations in women exposed to high altitude. Proper care for women at high altitudes should include monitoring of hormonal cycles and consideration of targeted antidepressant treatments.
FRONTIERS IN PHYSIOLOGY
(2023)
Article
Clinical Neurology
Congcong Liu, Keshuang Li, Meina Fu, Yingying Zhang, Cornelia Sindermann, Christian Montag, Xiaoxiao Zheng, Hongxing Zhang, Shuxia Yao, Zheng Wang, Bo Zhou, Keith M. Kendrick, Benjamin Becker
Summary: Serotonin plays a crucial role in emotion regulation and can contribute to the development and treatment of emotional dysregulations. A recent study found that individual variations in the TPH2 genetics may increase susceptibility to the detrimental effects of temporary decreases in 5-HT signaling, leading to increased anxiety and altered neural threat reactivity.
EUROPEAN NEUROPSYCHOPHARMACOLOGY
(2023)
Article
Medicine, General & Internal
Irene Gonzalez, Rocio Polvillo, Maximiliano Ruiz-Galdon, Armando Reyes-Engel, Jose Luis Royo
Summary: The study found that tryptophan supplementation has an uneven effect on mood improvement in the general population. Interindividual genetic differences may largely explain this variable response.
INTERNATIONAL JOURNAL OF GENERAL MEDICINE
(2021)
Article
Clinical Neurology
Tomas Weinert, Fabio Bernardoni, Joseph King, Julius Steding, Ilka Boehm, Merle Mannigel, Franziska Ritschel, Florian Zepf, Veit Roessner, Stefan Ehrlich
Summary: Previous studies suggest that individuals recovered from anorexia nervosa (AN) as well as those at risk for AN may exhibit increased serotonergic activity and elevated anxiety levels. This study found that experimentally induced short-term depletion of tryptophan (TRP), the precursor of serotonin (5-HT), did not effectively reduce anxiety or improve mood in weight-recovered AN patients. More research is needed to understand the role of 5-HT dysfunction in the pathophysiology of AN.
EUROPEAN ARCHIVES OF PSYCHIATRY AND CLINICAL NEUROSCIENCE
(2022)
Article
Psychology, Biological
Shi Yao, Meng Zhang, Shan-Shan Dong, Jia-Hao Wang, Kun Zhang, Jing Guo, Yan Guo, Tie-Lin Yang
Summary: Research suggests that there is a causal relationship between higher relative carbohydrate intake and lower depression risk. This protective effect is partly mediated by body mass index.
NATURE HUMAN BEHAVIOUR
(2022)
Article
Multidisciplinary Sciences
Bence Bruncsics, Gabor Hullam, Bence Bolgar, Peter Petschner, Andras Millinghoffer, Kinga Gecse, Nora Eszlari, Xenia Gonda, Debra J. Jones, Sorrel T. Burden, Peter Antal, Bill Deakin, Gyorgy Bagdy, Gabriella Juhasz
Summary: Manipulation of tryptophan intake can rapidly induce and alleviate depression symptoms. This study investigates the effect of habitual tryptophan intake on mood symptoms and the influence of genetic factors. High dietary tryptophan ratio provides a protective effect against depression. Genetic associations with depression are found in the low tryptophan ratio group, particularly in serotonin and kynurenine pathways. Understanding the interaction between genetics and diet can lead to personalized prevention and intervention for mood disorders.
SCIENTIFIC REPORTS
(2023)
Article
Biochemistry & Molecular Biology
Alexander Mordhorst, Priyavathi Dhandapani, Susann Matthes, Valentina Mosienko, Michael Rothe, Mihail Todiras, Julie Self, Wolf-Hagen Schunck, Anja Schutz, Michael Bader, Natalia Alenina
Summary: Serotonin synthesis involves the hydroxylation of tryptophan, with most vertebrates having two known enzymes for this step. However, even in animals lacking these two enzymes, there is still some serotonin production, suggesting the presence of a third enzyme. The study found evidence that phenylalanine hydroxylase (PAH) may act as a third tryptophan hydroxylase in mammals, contributing to serotonin levels in the blood and potentially serving as a local source of serotonin in organs where other TPHs are not expressed.
Article
Biochemistry & Molecular Biology
Jordi Marti, Huixia Lu
Summary: This study investigates the interactions of tryptophan, serotonin, and melatonin with zwitterionic phospholipid bilayers through molecular dynamics simulations. The presence of cholesterol influences the behavior of these small molecules, affecting their binding to the membrane. Free energy barriers and diffusion rates of the small molecules provide insights into their interaction with phospholipids and cholesterol in the membrane environment.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Oncology
Di Ye, Huanji Xu, Hongwei Xia, Chenliang Zhang, Qiulin Tang, Feng Bi
Summary: This study elucidated a novel mechanism in colon cancer involving targeting the serotonin transporter to promote the uptake and catabolism of extracellular tryptophan, leading to serotonin biosynthesis and production of oncogenic metabolites. Inhibition of serotonin transporter induced a compensatory effect by promoting tryptophan uptake and catabolism, ultimately enhancing the anti-tumor effects of selective serotonin reuptake inhibitors.
JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH
(2021)
Article
Multidisciplinary Sciences
Paul Bengart, Theo Gruendler, Bodo Vogt
Summary: The study shows that serotonin availability mediates (negative) reciprocal behavior in social decision-making. The reduction of serotonin availability leads to an increase in participants' preference for negative reciprocity in response to expected negative actions. Positive reciprocity, however, remains unaffected by serotonin depletion.
Article
Biochemistry & Molecular Biology
Sangwon Jang, Inah Park, Mijung Choi, Jihoon Kim, Seungeun Yeo, Sung-Oh Huh, Ji-Woong Choi, Cheil Moon, Han Kyoung Choe, Youngshik Choe, Kyungjin Kim
Summary: The circadian regulation of 5-HT levels, controlled by the nuclear receptor REV-ERBα, plays a significant role in social interaction behaviors. The genetic ablation of REV-ERBα in DR 5-HTergic neurons leads to impaired social preference, which is associated with elevated neuron activity and 5-HT levels at dusk. Furthermore, inhibiting the DR to NAc 5-HTergic circuit restores the impairment of social preference in these mice.
EXPERIMENTAL AND MOLECULAR MEDICINE
(2023)
Article
Gastroenterology & Hepatology
Yuanyuan Deng, Manfei Zhou, Junfeng Wang, Jiaxi Yao, Jing Yu, Wenwei Liu, Linlin Wu, Jun Wang, Rong Gao
Summary: The research found that long-term stress disrupts Kyn metabolism and endocrine function, accompanied by disrupted homeostasis of certain microbiota, collectively contributing to the development of depression-like behavior.
Article
Oncology
Nikos Papadimitriou, Marc J. Gunter, Neil Murphy, Audrey Gicquiau, David Achaintre, Stefanie Brezina, Tanja Gumpenberger, Andreas Baierl, Jennifer Ose, Anne J. M. R. Geijsen, Eline H. van Roekel, Andrea Gsur, Biljana Gigic, Nina Habermann, Cornelia M. Ulrich, Ellen Kampman, Matty P. Weijenberg, Per Magne Ueland, Rudolf Kaaks, Verena Katzke, Vittorio Krogh, Bas Bueno-de-Mesquita, Eva Ardanaz, Ruth C. Travis, Matthias B. Schulze, Maria-Jose Sanchez, Sandra M. Colorado-Yohar, Elisabete Weiderpass, Augustin Scalbert, Pekka Keski-Rahkonen
Summary: The study found that higher plasma tryptophan levels may be associated with a lower risk of colon cancer, while increased serotonin levels may be linked to a higher risk of colon cancer. Additionally, the kynurenine-to-tryptophan ratio may reflect altered tryptophan metabolism during colon cancer development.
INTERNATIONAL JOURNAL OF CANCER
(2021)
Article
Multidisciplinary Sciences
Julian H. Smith, Conor Rowland, B. Harland, S. Moslehi, R. D. Montgomery, K. Schobert, W. J. Watterson, J. Dalrymple-Alford, R. P. Taylor
Summary: The study investigates the fractal nature of neurons and its impact on functionality, showing that modifying dendritic patterns can create neurons with different fractal dimensions. The optimization of network cooperation reflects changes in neuron connectivity and associated costs, influencing healthy and pathological neurons as well as connections to medical implants.
SCIENTIFIC REPORTS
(2021)
Article
Computer Science, Hardware & Architecture
Dibash Basukala, Ramakrishnan Mukundan, Anthony Lim, Michael A. Hurrell, Ross J. Keenan, John C. Dalrymple-Alford, Tim J. Anderson, Daniel J. Myall, Tracy R. Melzer
Summary: This paper proposes an algorithm for segmenting SN and RN from QSM MRI, showing high-quality segmentations validated through comparison with expert manual segmentations. The study found moderate evidence of increased QSM values in SN in PD compared to controls, with a moderate association between QSM, global cognitive ability, and motor impairment in the SN in PD.
COMPUTERS & ELECTRICAL ENGINEERING
(2021)
Article
Clinical Neurology
Max A. Laansma, Joanna K. Bright, Sarah Al-Bachari, Tim J. Anderson, Tyler Ard, Francesca Assogna, Katherine A. Baquero, Henk W. Berendse, Jamie Blair, Fernando Cendes, John C. Dalrymple-Alford, Rob M. A. de Bie, Ines Debove, Michiel F. Dirkx, Jason Druzgal, Hedley C. A. Emsley, Gaetan Garraux, Rachel P. Guimaraes, Boris A. Gutman, Rick C. Helmich, Johannes C. Klein, Clare E. Mackay, Corey T. McMillan, Tracy R. Melzer, Laura M. Parkes, Fabrizio Piras, Toni L. Pitcher, Kathleen L. Poston, Mario Rango, Leticia F. Ribeiro, Cristiane S. Rocha, Christian Rummel, Lucas S. R. Santos, Reinhold Schmidt, Petra Schwingenschuh, Gianfranco Spalletta, Letizia Squarcina, Odile A. van den Heuvel, Chris Vriend, Jiun-Jie Wang, Daniel Weintraub, Roland Wiest, Clarissa L. Yasuda, Neda Jahanshad, Paul M. Thompson, Ysbrand D. van der Werf
Summary: The study used a multicenter approach and harmonized analysis methods to investigate brain structure abnormalities in Parkinson's disease patients. They found that patients had thinner cortex in certain regions compared to healthy controls, with differences increasing with disease severity. Poorer cognition was associated with widespread cortical thinning and lower volumes of core limbic structures.
MOVEMENT DISORDERS
(2021)
Article
Clinical Neurology
Campbell Le Heron, Michael MacAskill, Deborah Mason, John Dalrymple-Alford, Tim Anderson, Toni Pitcher, Daniel Myall
Summary: The age-specific incidence of Parkinson's disease suggests a multistep pathogenic process, with an average of six steps before age 45 and eight steps after. The model supports theories that emphasize the role of environmental factors in driving sex differences in disease incidence.
MOVEMENT DISORDERS
(2021)
Article
Clinical Neurology
Judith A. Boel, Rob M. A. Bie, Ben A. Schmand, John C. Dalrymple-Alford, Connie Marras, Charles H. Adler, Jennifer G. Goldman, Alexander Troster, David J. Burn, Irene Litvan, Gert J. Geurtsen
Summary: The predictive value of global cognitive tests for conversion from PD-MCI to PDD is lower compared to comprehensive neuropsychological assessment. Level II neuropsychological assessment is the preferred method for evaluating PD-MCI.
MOVEMENT DISORDERS CLINICAL PRACTICE
(2022)
Article
Clinical Neurology
Joseph Blommer, Toni Pitcher, Maja Mustapic, Erden Eren, Pamela J. Yao, Michael P. Vreones, Krishna A. Pucha, John Dalrymple-Alford, Reza Shoorangiz, Wassilios G. Meissner, Tim Anderson, Dimitrios Kapogiannis
Summary: The protein cargo of neuronal extracellular vesicles may serve as a biomarker for cognitive impairment in Parkinson's disease, with differences in alpha-synuclein, phosphorylated tau, and proteins associated with insulin signaling observed between patients with and without cognitive impairment. These findings could provide insights into the underlying pathogenic processes and improve diagnosis and prognosis of Parkinson's disease. Plasma samples from 273 participants were used in the study, and immunoassays were utilized to quantify biomarkers in plasma extracellular vesicles enriched for neuronal origin. Alpha-synuclein, phosphorylated tau, and insulin receptor substrate-1 phosphorylated tyrosine showed diagnostic classification contributions between groups, indicating that both alpha-synuclein and tau pathologies, along with impaired insulin signaling, may underlie Parkinson's disease with cognitive impairment. Plasma neuronal extracellular vesicles biomarkers may inform cognitive prognosis in Parkinson's disease.
Article
Multidisciplinary Sciences
Michael R. MacAskill, Toni L. Pitcher, Tracy R. Melzer, Daniel J. Myall, Kyla-Louise Horne, Reza Shoorangiz, Mustafa M. Almuqbel, Leslie Livingston, Sophie Grenfell, Maddie J. Pascoe, Ethan T. Marshall, Steven Marsh, Sarah E. Perry, Wassilios G. Meissner, Catherine Theys, Campbell J. Le Heron, Ross J. Keenan, John C. Dalrymple-Alford, Tim J. Anderson
Summary: The New Zealand Parkinson's Progression Programme (NZP3) focuses on studying cognitive impairment in Parkinson's disease patients, identifying biomarkers and standard criteria for mild cognitive impairment (MCI). The programme utilizes brain imaging techniques such as MRI and PET to show associations between brain pathology and declining cognitive function. It also explores other biomarkers including genetics, fluid biomarkers, eye movement, speech, and EEG.
JOURNAL OF THE ROYAL SOCIETY OF NEW ZEALAND
(2023)
Article
Physiology
Conor Rowland, Bruce Harland, Julian H. Smith, Saba Moslehi, John Dalrymple-Alford, Richard P. Taylor
Summary: The study explores the relationship between fractal scaling of neuronal dendrites and connectivity, considering the impact of pathological states on this optimization process. Rats exposed to enriched housing and spatial memory training exhibited higher complexity and connectivity in dendritic arbors. The findings suggest that morphological differences induced by lesions are not significant enough to affect the optimization process in achieving an optimal balance between connectivity and material cost.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Neurosciences
Jennifer J. Hamilton, John C. Dalrymple-Alford
Summary: Injury or dysfunction in the anterior thalamic nuclei (ATN) plays a crucial role in diencephalic amnesia. Experimental studies have shown that ATN lesions impair spatial memory and temporal discriminations, but the role in non-spatial memory is limited. This study demonstrates that ATN lesions completely block the acquisition of biconditional associations between odour and object pairings, suggesting that diencephalic amnesia associated with ATN stems from degraded attention to stimulus-stimulus associations.
EUROPEAN JOURNAL OF NEUROSCIENCE
(2022)
Article
Multidisciplinary Sciences
Lynette J. Tippett, Erin E. Cawston, Catherine A. Morgan, Tracy R. Melzer, Kiri L. Brickell, Christina Ilse, Gary Cheung, Ian J. Kirk, Reece P. Roberts, Jane Govender, Leon Griner, Campbell Le Heron, Sarah Buchanan, Waiora Port, Makarena Dudley, Tim J. Anderson, Joanna M. Williams, Nicholas J. Cutfield, John C. Dalrymple-Alford, Phil Wood
Summary: This study aims to explore and improve understanding of Alzheimer's Disease and dementia, in order to delay or prevent the progression of dementia. Through multidisciplinary collaboration, regular examinations are conducted on community participants to collect and analyze various biomarkers and risk factors, and to study the mechanisms underlying disease progression. The national outreach of the Dementia Prevention Research Clinics is one of its strengths.
JOURNAL OF THE ROYAL SOCIETY OF NEW ZEALAND
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Catherine A. Morgan, Reece P. Roberts, Tessa Chaffey, Lenore Tahara-Eckl, Meghan van der Meer, Matthias Gunther, Timothy J. Anderson, Nicholas J. Cutfield, John C. Dalrymple-Alford, Ian J. Kirk, Donna Rose Addis, Lynette J. Tippett, Tracy R. Melzer
Summary: This study assessed the repeatability and reproducibility of MRI markers derived from a dementia protocol, finding that structural markers were less variable than functional MRI markers.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2022)
Review
Biochemistry & Molecular Biology
Jian Guan, Fengxia Li, Dali Kang, Tim Anderson, Toni Pitcher, John Dalrymple-Alford, Paul Shorten, Gagandeep Singh-Mallah
Summary: The decline of insulin-like growth factor-1 (IGF-1) function with age is associated with brain aging and age-related neurological conditions. Cyclic glycine-proline (cGP) and IGF binding protein-3 (IGFBP-3) collectively regulate the bioavailability of IGF-1. The ratio of cGP/IGF-1 is associated with clinical outcomes, memory retention, and age-related brain diseases.
Article
Clinical Neurology
Eloise A. Gooch, Kyla-Louise Horne, Tracy R. R. Melzer, Megan J. J. McAuliffe, Michael MacAskill, John C. C. Dalrymple-Alford, Tim J. J. Anderson, Catherine Theys
Summary: New-onset stuttering occurs in individuals with Parkinson's disease and is related to cognitive and motor functioning. People with Parkinson's disease have a higher occurrence of stuttering during conversation compared to controls. The frequency of stuttering is associated with disease onset, medication dosage, and cognitive and motor scores.
MOVEMENT DISORDERS CLINICAL PRACTICE
(2023)
Article
Medicine, General & Internal
Rebekah L. Blakemore, Maddie J. Pascoe, Kyla-Louise Horne, Leslie Livingston, Bob N. Young, Beth Elias, Marie Goulden, Sophie Grenfell, Daniel J. Myall, Toni L. Pitcher, John C. Dalrymple-Alford, Campbell J. Le Heron, Tim J. Anderson, Michael R. MacAskill
Summary: This study found that perceived stress was higher in Parkinson's disease patients during the COVID-19 lockdown, especially in those reporting worsening of tremor, balance/gait, dyskinesia, and bradykinesia. These effects were not modulated by physical activity.
NEW ZEALAND MEDICAL JOURNAL
(2021)
Article
Biotechnology & Applied Microbiology
Marta F. Nabais, Simon M. Laws, Tian Lin, Costanza L. Vallerga, Nicola J. Armstrong, Ian P. Blair, John B. Kwok, Karen A. Mather, George D. Mellick, Perminder S. Sachdev, Leanne Wallace, Anjali K. Henders, Ramona A. J. Zwamborn, Paul J. Hop, Katie Lunnon, Ehsan Pishva, Janou A. Y. Roubroeks, Hilkka Soininen, Magda Tsolaki, Patrizia Mecocci, Simon Lovestone, Iwona Kloszewska, Bruno Vellas, Sarah Furlong, Fleur C. Garton, Robert D. Henderson, Susan Mathers, Pamela A. McCombe, Merrilee Needham, Shyuan T. Ngo, Garth Nicholson, Roger Pamphlett, Dominic B. Rowe, Frederik J. Steyn, Kelly L. Williams, Tim J. Anderson, Steven R. Bentley, John Dalrymple-Alford, Javed Fowder, Jacob Gratten, Glenda Halliday, Ian B. Hickie, Martin Kennedy, Simon J. G. Lewis, Grant W. Montgomery, John Pearson, Toni L. Pitcher, Peter Silburn, Futao Zhang, Peter M. Visscher, Jian Yang, Anna J. Stevenson, Robert F. Hillary, Riccardo E. Marioni, Sarah E. Harris, Ian J. Deary, Ashley R. Jones, Aleksey Shatunov, Alfredo Iacoangeli, Wouter van Rheenen, Leonard H. van den Berg, Pamela J. Shaw, Cristopher E. Shaw, Karen E. Morrison, Ammar Al-Chalabi, Jan H. Veldink, Eilis Hannon, Jonathan Mill, Naomi R. Wray, Allan F. McRae
Summary: This study identified shared differentially methylated positions in whole blood between neurodegenerative disorders, indicating shared pathogenic mechanisms. Immune abnormalities caused by different neurodegenerative diseases may be interrelated to some extent.
