The Relationship between Cytokines and Verbal Memory in Individuals with Schizophrenia and Their Unaffected Siblings

Abstract

Background: Verbal memory impairment may be considered an endophenotype in schizophrenia (SZ), also affecting the siblings of SZ subjects. Furthermore, the immune-inflammatory system response has an important modulatory effect on brain processes, especially on memory circuits. Objective: Investigating the relationship between TNF-α and IL-6 and memory performance in patients with SZ, their unaffected siblings (SB) and healthy controls (HC). Methods: 35 subjects with SZ, 36 SB, and 47 HC underwent a neurocognitive assessment for verbal memory by means of the revised Hopkins Verbal Learning Test (HVLT-R) in addition to serum cytokines analyses. Results: SZ patients performed worse in HVLT-R than SB and HC, but SB and HC were not different. Regarding the biomarker levels, we found significant results of TNF-α for both groups. However, we did not find differences between groups after multiple-comparisons analysis. There were no significant correlations between episodic verbal memory, TNF-α, and IL-6. Conclusion: The results are compatible with the hypothesis that deficits in verbal memory of individuals with SZ could be secondary to inadequate functioning of cognitive processing areas, such as proactive cognitive control.

Impaired large-scale cortico–hippocampal network connectivity, including the anterior temporal and posterior medial systems, and its associations with cognition in patients with first-episode schizophrenia

“…The hippocampus, PHC, and amygdala are critical constituents of the cortical and subcortical limbic system and participate in the regulation of emotional reactions, learning, memory, and behavior. In this study, the functional connectivity of the precuneus with the amygdala, hippocampus, and PHC is weakened, which is consistent with the findings of a study by Wen et al ( 2021 ), suggesting that the altered connectivity between the precuneus and the limbic system lays the neurobiological foundation for the decline of cognitive function and intensification of negative symptoms in schizophrenia (Berman et al, 2016 ; Rebouças et al, 2018 ). Our study also identified decreased FC between the RSC and the PCCR.…”

Koncepcja endofenotypu w badaniach porównawczych zaburzeń funkcji poznawczych osób chorujących na schizofrenię i ich zdrowego rodzeństwa. Przegląd piśmiennictwa z lat 2010–2020

“…Tak więc wynik pracy wydaje się być zgodny z hipotezą, że deficyty w pamięci werbalnej osób ze SZ mogą być wtórne do niewłaściwego funkcjonowania obszarów przetwarzania poznawczego. Nie ma jednak podstaw do przyjęcia, że tło opisanych nieprawidłowości może być innego rodzaju, na przykład proces zapalny [33]. Wykorzystano Skalę Anhedonii Społecznej, Skalę Czasowego Doświadczenia Przyjemności i Kwestionariusz Osobowości Schizotypowej.…”