February 22, 2021, by mstalniceanu

New research from the School of Life Sciences shows promise in the fight against cognitive decline

By Emma Gow, 3^rd Year Neuroscience BSc

Cognition is the combination of many mental processes that lead to the acquisition of knowledge or understanding. This can include the functions of conceptual understanding, reasoning, written and verbal communication, problem solving, memory, attention, and participation in the community [1]. Cognitive functions are obviously very important in everyday activities, however there are many conditions in which there are notable cognitive impairments that can severely disrupt day-to-day life for the sufferers. In recent times there has been many developments in this field, including important breakthroughs from the School of Life Sciences, that have brought us one step closer to a potential treatment for those dealing with cognitive impairment.

One condition that causes this cognitive decline is Alzheimer’s disease, a neurodegenerative disease that causes lesions and degradation within the brain [2]. Alzheimer’s disease is the most prevalent form of dementia, with up to 50 million people suffering worldwide with the condition [3]. Patients show significant cognitive deficits that worsen with age, particularly loss of memory [2], which can cause great distress for both the sufferer and their loved ones.

Autism spectrum disorder (ASD) is a neurodevelopmental condition that is characterised by social difficulties, including problems with communication and interactions [4]. A significant proportion of people with ASD also show regression of cognitive skills at a young age, such as language and communication, that continue into adulthood [4]. As the name suggests, there is a spectrum of different presentations of symptoms across all people with ASD, however some autistic people do suffer more than others and those with severe forms of ASD can show profound cognitive disabilities [5].

Although less recognised by the general public, schizophrenia also has a large cognitive component that can cause a significant impact to the patient’s life. Schizophrenia is a psychiatric condition that causes delusions, hallucinations, and psychosis. Despite most people only think of these so called ‘positive’ symptoms, a large aspect of schizophrenia is the ‘negative’ symptoms, which includes social cognitive deficits [6]. Schizophrenia can cause dementia like symptoms such as verbal memory and attention loss, so much so that it was originally called ‘dementia praecox’ [7]. These social cognitive impairments can lead to poor functioning within communities due to lack of emotional recognition, and the dementia-like symptoms can cause general disability and lack of independence [6].

Cognitive impairment can lead to a significantly reduced quality of life for the sufferer. It can massively affect the patients ability to live independently; for example, the severe loss of memory and recognition in Alzheimer’s patients can be dangerous for those living alone, especially in the later stages of the disease. So, with our ever-growing population, it is important that a treatment is identified for patients with cognitive decline. Potential drug therapies to improve the symptoms of cognitive impairment in patients with many of the conditions mentioned could help a significant proportion of the population live a more fulfilling life.

A recent study from the School of Life Sciences, led by Professor Kevin Fone, has highlighted a potential drug mechanism and target that could help in the treatment of patients with cognitive impairment [8]. The study focused on NMDA receptors as a drug target and compared the efficacy of drugs targeting the binding of the neurotransmitter glycine on these receptors. NMDA has an extremely important role in cognition and mood regulation, with levels notably lowered in schizophrenia patients, so acting on this receptor could show promising results in helping patients with cognitive decline. They found that glycine reuptake inhibitors and partial agonists of glycine were the most effective drugs for increasing cognitive abilities in rats with induced cognitive impairment. The rats given these experimental compounds showed an improved performance in novel object recognition and social recognition tasks. In additional studies, drugs such as the ones in this experiment have been found to be potentially useful in many conditions that cause cognitive impairment, such as Alzheimer’s disease, ASD, schizophrenia and even Parkinson’s disease.

Although this is not an exact cure to any of the conditions, it is a step in the right direction. This gives the potential for people with cognitive impairment to have an improved quality of life and could allow for greater independence despite their condition.

People with cognitive impairment show dysfunction in many aspects of life through no fault of their own, but new discoveries may be able to aid them in this struggle.

Image by ElisaRiva from Pixabay 

References

[1]	J. G. Greeno, A. M. Collins and L. B. Resnick, “Cognition and Learning,” in Handbook of Educational Psychology, 1996, pp. 15-46.
[2]	F. Gaubert and H. Chainay, “Decision-Making Competence in Patients with Alzheimer’s Disease: A Review of the Literature,” Neuropsychology Review, 2021.
[3]	A. Lladó, L. Froelich, R. K. Khandker, M. Roset, C. M. Black, N. Lara , F. Chekani and B. M. Ambegaonkar, “Assessing the Progression of Alzheimer’s Disease in Real-World Settings in Three European Countries,” Journal of Alzheimer’s Disease, pp. 1-11, 2021.
[4]	C. Miniscalco and E. Carlsson, “A longitudinal case study of six children with autism and specified language and non-verbal profiles,” Clinical Linguistics and Phonetics , pp. 1-19, 2021.
[5]	R. Chapman, “Neurodiversity and the Social Ecology of Mental Functions,” Perspectives on Psychological Science: A journal of the Association for Psychological Science, p. 1745691620959833, 2021.
[6]	L. D. Oliver, C. Hawco, P. Homan, J. Lee, M. F. Green, J. M. Gold, P. DeRosse, M. Argyelan, A. K. Malhotra, R. W. Buchanan and A. N. Voineskos, “Social Cognitive Networks and Social Cognitive Performance Across Individuals With Schizophrenia Spectrum Disorders and Healthy Control Participants,” Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, pp. S2451-9022(20)30356-6., 2020.
[7]	A. Jablensky, “The diagnostic concept of schizophrenia: its history, evolution, and future prospects,” Dialogues in Clinical Neuroscience, vol. 12, no. 3, pp. 271-287, 2010.
[8]	K. C. Fone, D. J. Watson, R. I. Billiras, D. I. Sicard, A. Dekeyne, J.-M. Rivet, A. Gobert and M. J. Millan, “Comparative Pro-cognitive and Neurochemical Profiles of Glycine Modulatory Site Agonists and Glycine Reuptake Inhibitors in the Rat: Potential Relevance to Cognitive Dysfunction and Its Management,” Molecular Neurobiology, vol. 57, no. 5, pp. 2144-2166, 2020.

 

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