Prenatal exposure to artificial food colorings alters NMDA receptor subunit concentrations in rat hippocampus

ABSTRACT

Exposure to artificial food color additives (AFCAs) has been implicated in the etiology of certain childhood hyperactivity and learning disabilities. N-methyl-D-aspartate receptors and alpha-7 nicotinic acetylcholine receptor (α7 nAChR) are involved in learning and memory. We administered a mixture of AFCAs (erythrosine, ponceau 4R, allura red AC, sunset yellow FCF, tartrazine, amaranth, brilliant blue, azorubine, and indigotine) to female rats during gestation to investigate the effects of prenatal exposure to AFCAs on neurobehavior, spatial learning, and memory in their offspring. We also investigated whether AFCAs modulate NR2A, NR2B, and α7 nAChR protein levels in their offsprings’ hippocampi. Although spatial learning and memory were not altered, the offspring of rats exposed to AFCAs exhibited decreased motivation and increased despair-related behavior. NR2A and NR2B protein levels were significantly reduced in female offspring in the experimental group (p < 0.05), whereas α7 nAChR level was not significantly altered. Our results suggest that prenatal exposure to AFCAs may lead to sex-dependent alterations in glutamatergic signaling which may continue into adolescence.

KEYWORDS:

• Artificial food colors
• spatial learning and memory
• NR2A
• NR2B
• α7 nAChR
• open field test
• forced swim test
• NMDARs

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

First part of this research (Neurobehavioral analyses) was supported by Suleyman Demirel University [grant number 3110-TU-12], covering expenses of the chemicals and analyses of receptor levels which were the continuous part of the research were provided by researchers.

Notes on contributors

Duygu Kumbul Doguc

Duygu Kumbul Doguc is M.D., graduated from Medical School of Akdeniz University, depended on the examination of Medical Spesification, she completed her medical specification and majored in Medical Biochemistry Department of Suleyman Demirel University and became specialist of Medical Biochemistry, and has been working as a lecturer in the same department and continued her academic upgrade as Assistant Professor, Associated Professor in the same department. Duygu K Doguc studies on Learning, Memory, Neurobehaviour and food additives.

Firdevs Deniz

Firdevs Deniz is M.D., graduated from Medical School of Akdeniz University, depended on the examination of Medical Spesification, she completed her medical specification and majored in Medical Biochemistry Department of Suleyman Demirel University and became specialist of Medical Biochemistry and has been working as a specialist of Medical Biochemistry in Atatürk Goverment Hospital for 4 years.

İlter İlhan

İlter İlhan is MD, graduated from Medical School of Suleyman Demirel University, depended on the examination of Medical Spesification, he completed his medical spesification and majored in Medical Biochemistry Department of Suleyman Demirel University and became specialist of Medical Biochemistry, and has been working as a lecturer in the same department for 2 years and still Assisstant Professor in the same department. İlter İlhan studies on Oxidative stress, Learning, Memory, Neurobehaviour and food additives.

Esin Ergonul

Esin Ergonul is M.D., graduated from Medical School of Dokuz Eylul University, depended on the examination of Medical Spesification, she completed her medical specification and majored in Public Health of Dokuz Eylul University and became specialist of Public Health and continued her PhD education in Department of Medical Education, Medical School of Akdeniz University. She has been working as a lecturer and Assistant Professor in Medical Education Department, Medical School of Dokuz Eylul University. She studies Medical education, Education styles and Learning.

Fatih Gultekin

Fatih Gültekin is M.D., graduated from Medical School of Selcuk University, and also completed the Ph.D. education in the Medical School of Selcuk University, Medical Biochemistry Department. He worked in Medical School of Suleyman Demirel University, Medical Biochemistry Department as an Assistant Professor and then Associated Professor and Professor for 16 years. He still works as a lecturer in University of Health Sciences, School of Medicine, Medical Biochemistry Department. He studies on Food Additives, wrote a ‘Consumers' Book’ in Turkish.