STM Journals Peer-reviewed research from Consortium e-Learning Network

Research and Reviews : A Journal of Life Sciences Original Research

Effect of Toxoplasma gondii on some Neurotransmitter Levels in Patients with Toxoplasmosis Infection

  1. Raja Jawad Mohamed Department of Medical Laboratory Techniques, Technical Institute, Al-Furat Al-Awsat Technical University 31001, Kufa,

Abstract

Background: The study of Toxoplasma gondii on some neurotransmitter levels in patients with toxoplasmosis infection is one of the challenges of sustainable development. Toxoplasma gondii is a parasite that can alter host behavior by affecting neurotransmitters of the host.

Aim: To diagnose if there are differences in neurotransmitter levels in infected people by toxoplasmosis and healthy people to predict the psychological and neurological diseases.

Methods: The study included collecting 60 samples, 30 of which were from people infected with toxoplasmosis and 30 from healthy people. These people were visitors to the Middle Euphrates Center for Neurosciences during the period from August 2024 to January 2025. The presence of antibodies to the toxoplasmosis parasite was investigated using the ELISA test and the test kit from Calbiotech. The ages of the people included in the study ranged from 20 to 69 years. Verbal and written consent was obtained from them, and the content and purpose of the study were explained to them. The study also included investigations into education. 5 ml of blood samples were withdrawn from the people included in the study, the serum was isolated from the rest of the blood components, and the concentrations of neurotransmitters were investigated using the ELISA technique and the Elabscience kit.

Results: The results showed that the number of infected men was more than women, and that most of the infected were Gainers, and that the age group between 40 and 59 was the most affected. The results of the current study also showed that people infected with toxoplasmosis had significant differences with healthy people, as they had higher concentrations of adrenaline compared to healthy people. However, when comparing the levels of neurotransmitters between healthy men and women, there were no significant differences. However, between men and women infected with toxoplasmosis, significant differences were shown, as the dopamine concentration rate was higher in women compared to men.

Conclusion: The results of the current study confirmed the proposed mechanism by which the toxoplasmosis parasite may induce behavioral changes in hosts via the parasite’s influence on the levels of certain neurotransmitters. There was no significant effect of gender on neurotransmitter levels when compared to healthy controls, but there was an increase in dopamine levels in women when compared to those infected with the toxoplasmosis parasite. We can also conclude that some psychiatric and neurological diseases, such as schizophrenia and Parkinson’s disease, may be caused by infection with the toxoplasmosis parasite.

Keywords

References (39)

  1. Madireddy S, Mangat R. Toxoplasmosis. [Updated 2024 Oct 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563286/
  2. Hernandez-Caballero I, Garcia-Longoria L, Gomez-Mestre I, Marzal A. The Adaptive Host Manipulation Hypothesis: Parasites Modify the Behaviour, Morphology, and Physiology of Amphibians. Diversity. 2022;14(9):739. doi:10.3390/d14090739
  3. House PK, Vyas A, Sapolsky R. Predator Cat Odors Activate Sexual Arousal Pathways in Brains of Toxoplasma gondii Infected Rats. PLoS ONE. 2011;6(8):e23277. doi:10.1371/journal.pone.0023277
  4. Latifi A, Flegr J. Beyond Latency: Chronic Toxoplasma Infection and Its Unveiled Behavioral and Clinical Manifestations—A 30-Year Research Perspective. Biomedicines. 2025;13(7):1731. doi:10.3390/biomedicines13071731
  5. Sheffler ZM, Reddy V, Pillarisetty LS. Physiology, Neurotransmitters. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539894/
  6. Caire MJ, Reddy V, Varacallo MA. Physiology, Synapse. [Updated 2023 Mar 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526047/
  7. Hasan Kadhum Al-Huchaimi S, Hameed Neamah Al-Kefaei G, Ahmed Alameedy B. Effects of Toxoplasma gondiion Levels of Interleukin-5 in Parkinson's Patients. Arch Razi Inst. 2022;77(1):213-220. Published 2022 Feb 28. doi:10.22092/ARI.2021.356478.1850
  8. Akins GKH, Furtado JM, Smith JR. Diseases Caused by and Behaviors Associated with Toxoplasma gondii Infection. Pathogens. 2024;13(11):968. doi:10.3390/pathogens13110968
  9. Vyas A, Kim SK, Giacomini N, Boothroyd JC, Sapolsky RM. Behavioral changes induced by Toxoplasma infection of rodents are highly specific to aversion of cat odors. Proceedings of the National Academy of Sciences. 2007;104(15):6442-6447. doi:10.1073/pnas.0608310104
  10. Cromar GL, Epp JR, Popovic A, Gu Y, Ha V, Walters BJ, et al. Toxoplasma infection in male mice alters dopamine-sensitive behaviors and host gene expression patterns associated with neuropsychiatric disease. PLOS Neglected Tropical Diseases. 2022;16(7):e0010600. doi:10.1371/journal.pntd.0010600
  11. Virus MA, Ehrhorn EG, Lui LM, Davis PH. Neurological and Neurobehavioral Disorders Associated with Toxoplasma gondii Infection in Humans. Journal of Parasitology Research. 2021;2021:1-18. doi:10.1155/2021/6634807
  12. Prandovszky E, Gaskell E, Martin H, Dubey JP, Webster JP, McConkey GA. The Neurotropic Parasite Toxoplasma Gondii Increases Dopamine Metabolism. PLoS ONE. 2011;6(9):e23866. doi:10.1371/journal.pone.0023866
  13. Khalil B, Rosani A, Warrington SJ. Physiology, Catecholamines. [Updated 2024 Dec 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507716/
  14. Salomão Lopes C, Carvalho RJV, da Silva TL, Barros HLS, Costa LVS, Mota DCAM, et al. Pregnant Women Chronically Infected by Toxoplasma gondii with Depressive Disorder: Differential Modulation of Pro-Inflammatory and Anti-Inflammatory Cytokines. Pathogens. 2025;14(4):330. doi:10.3390/pathogens14040330
  15. AL-Huchaimi SHK, Taiban ZK, Mohamed RJ, AL-Hadrawi MK, Ahmed ER. Immunological evaluation of rheumatoid factor level in cupping rheumatoid arthritis patients in Al-Najaf governorate. AIP Conference Proceedings. 2024;3092:020011. doi:10.1063/5.0199693
  16. Yang Y, Tao Y. Regenerating Locus Coeruleus‐Norepinephrine (LC‐NE) Function: A Novel Approach for Neurodegenerative Diseases. Cell Proliferation. 2025;58(6). doi:10.1111/cpr.13807
  17. Srinivasan J, Schmidt WJ. Functional recovery of locus coeruleus noradrenergic neurons after DSP-4 lesion: effects on dopamine levels and neuroleptic induced ? Parkinsonian symptoms in rats. Journal of Neural Transmission. 2004;111(1):13-26. doi:10.1007/s00702-003-0062-2
  18. Ibtihal Kareem Mahdi, Bashaer Jabar Hussein ,Aseel Fatek Tmkin. (2025). The effect of some Variables on Asthmatic Patients with Different Age and Compere with Control Group., Al-Harf Journal., No. 24 ., Vol. 3, August 2025
  19. Vargas-Villavicencio JA, Cañedo-Solares I, Correa D. Anti-Toxoplasma gondii IgM Long Persistence: What Are the Underlying Mechanisms? Microorganisms. 2022;10(8):1659. doi:10.3390/microorganisms10081659
  20. Al-Fatlawi MMH, Al-Ammar MH, Al-Manssori YLH. RETRACTED: Study of gene expression of Cytokine Genes (TLR-4, NOD-2) in patients with Otitis Media in Al-Najaf Governorate, Iraq. BIO Web of Conferences. 2024;84:03019. doi:10.1051/bioconf/20248403019
  21. Omidian M, Asgari Q, Bahreini MS, Moshki S, Sedaghat B, Adnani Sadati SJ. Acute toxoplasmosis can increase serum dopamine level. Journal of Parasitic Diseases. 2021;46(2):337-342. doi:10.1007/s12639-021-01447-1
  22. Saad MH, Safwat O, El-Guindy D, Raafat R, Elgendy D, Hasby E. Biomolecular changes and cortical neurodegenerative lesions in Trichinella spiralis infected BALB/c mice: a preliminary study elucidating a potential relationship between systemic helminthic infections and idiopathic Parkinson’s. Helminthologia. 2018;55(4):261-274. doi:10.2478/helm-2018-0029
  23. Melzer TC, Cranston HJ, Weiss LM, Halonen SK. Host Cell Preference of Toxoplasma gondii Cysts in Murine Brain: A Confocal Study. Journal of Neuroparasitology. 2010;1:1-6. doi:10.4303/jnp/n100505
  24. Z Jawad N, W H Yahya, A Kamel Abdulhussain, B Abdulhasan Nasir. (2025). A study of The effect of Alcoholic Extract of Celery Seeds on The Concentration of Sex Hormones in Male White Rats Treated with Depakine., Al-Harf Journal., No. 24 ., Vol.1, March 2025
  25. Cerutti A, Blanchard N, Besteiro S. The Bradyzoite: A Key Developmental Stage for the Persistence and Pathogenesis of Toxoplasmosis. Pathogens. 2020;9(3):234. doi:10.3390/pathogens9030234
  26. Zhang Z, Li Y, Li H, Song X, Ma Z, Lu H, et al. Identification of Toxoplasma Gondii Tyrosine Hydroxylase (TH) Activity and Molecular Immunoprotection against Toxoplasmosis. Vaccines. 2020;8(2):158. doi:10.3390/vaccines8020158
  27. AL-Huchaimi, S. H. K., Jassim, A., AL-Hadad, M. T. S., & AL-Ammar, M. H. ). Detection Of Pathogenicity Markers Produced By Pseudomonas aeruginosa causing Skin Infection. Plant Archives, ,18(1),, 621-626. 2018.DOI:13140/RG.2.2.21153.63843.
  28. Martin HL, Alsaady I, Howell G, Prandovszky E, Peers C, Robinson P, et al. Effect of parasitic infection on dopamine biosynthesis in dopaminergic cells. Neuroscience. 2015;306:50-62. doi:10.1016/j.neuroscience.2015.08.005
  29. Matt SM, Nolan R, Manikandan S, Agarwal Y, Channer B, Oteju O, et al. Dopamine-driven increase in IL-1β in myeloid cells is mediated by differential dopamine receptor expression and exacerbated by HIV. Journal of Neuroinflammation. 2025;22(1). doi:10.1186/s12974-025-03403-9
  30. AL-Saeedi RJM, AL-Hadraawy MK, Abdulgabar ZS, Khudair K. Microbial factors causing recurrent miscarriage a survey study for women in the Al Najaf governorate, Iraq. AIP Conference Proceedings. 2023;2776:020014. doi:10.1063/5.0135970
  31. Lotsios NS, Arvanitis N, Charonitakis AG, Mpekoulis G, Frakolaki E, Vassilaki N, et al. Expression of Human L-Dopa Decarboxylase (DDC) under Conditions of Oxidative Stress. Current Issues in Molecular Biology. 2023;45(12):10179-10192. doi:10.3390/cimb45120635
  32. Sarah Hasan Kadhum AL Huchaimi, Maysoon Khudair AL Hadrawi, Raja Jawad Mohmad. A Review on The effect of Polycystic Ovary Syndrome on some Hormonal and Metabolic Disturbances in Women. Research and Reviews: A Journal of Microbiology and Virology. 2024; 15(01):21-28.
  33. Guevara RB, Fox BA, Bzik DJ. Toxoplasma gondii Parasitophorous Vacuole Membrane-Associated Dense Granule Proteins Regulate Maturation of the Cyst Wall. mSphere. 2020;5(1). doi:10.1128/msphere.00851-19
  34. Slota C, Shi A, Chen G, Bevans M, Weng NP. Norepinephrine preferentially modulates memory CD8 T cell function inducing inflammatory cytokine production and reducing proliferation in response to activation. Brain, Behavior, and Immunity. 2015;46:168-179. doi:10.1016/j.bbi.2015.01.015
  35. Gulshan JE, Lira SS, Qusar MMAS, Hosen MI, Rahman A, Islam MR, et al. Association Between Toxoplasma gondii Infection and Serum Neurotransmitter Levels in Major Depressive Disorder Patients: A Case‐Control Study in Bangladesh. Journal of Parasitology Research. 2024;2024(1). doi:10.1155/japr/7054920
  36. Kolnikaj TS, Musat M, Salehidoost R, et al. Pharmacological Causes of Hyperprolactinemia. [Updated 2024 Jan 4]. In: Feingold KR, Ahmed SF, Anawalt B, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK599196/
  37. Dazzi F, Scicchitano C. Neurotrasmettitori: differenze di genere. Rivista di Psichiatria. 2014;49(5). doi:10.1708/1668.18264
  38. Mohammadpour A, Keshavarz H, Mohebali M, Salimi M, Teimouri A, Shojaee S. The relation of serum prolactin levels and Toxoplasma infection in humans. International Journal of General Medicine. 2018;Volume12:7-12. doi:10.2147/ijgm.s188525
  39. Abdoli A, Ghaffarifar F, Sharifi Z, Taghipour A. Toxoplasma gondii infection and testosterone alteration: A systematic review and meta-analyses. PLOS ONE. 2024;19(4):e0297362. doi:10.1371/journal.pone.0297362
Support