Miloslav Brejcha

@bc.cas.cz

Insitute of Entomology, Department of Molecular Biology and Genetics, Laboratory of Telomere Research
Biology Centre CAS

Miloslav Brejcha


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https://researchid.co/brejslav

RESEARCH, TEACHING, or OTHER INTERESTS

Molecular Biology, Genetics, Physiology
4

Scopus Publications

Scopus Publications

  • Multilevel impact of cocaine on honeybees: From neurochemistry and mitochondrial dysfunction to superorganism
    Dalibor Kodrík, Jan Černý, Jana Jemelková, Petr Kozel, Michala Sábová, Radmila Čapková Frydrychová, Miloslav Brejcha, Jiří Danihlík, Martin Kuchař, Helena Štěrbová, Jiří Dvořáček
    Biomedicine and Pharmacotherapy, 2026
    Cocaine abuse remains a serious global problem with far-reaching health, economic, social, and criminal consequences. Therefore, continued research on the mechanisms underlying cocaine effects is highly desirable. Utilizing invertebrate models in this field offers significant practical advantages, while a comparative approach can further broaden the understanding of fundamental physiological principles. This study highlights the honeybee Apis mellifera as a promising model for investigating the effects of single cocaine dose at both the individual and collective/social levels. Our results show that acute cocaine administration triggers a complex array of neurochemical, behavioral, and subcellular-toxic changes, each characterized by distinct temporal dynamics. The 'neurochemical-behavioral' axis manifested through altered biogenic amine levels, which are analogous to the mammalian response. Concurrently, the 'subcellular-toxic' axis, encompasses a cascade of mitochondrial abnormalities, reduced citrate synthase activity, and a compensatory antioxidant response. Furthermore, the impact of a single treatment was assessed by monitoring vibroacoustic signals—a likely manifestation of social communication within the hive—, which exhibited a notable latency compared to the biochemical/ultrastructural alterations at an individual level. These signals may indicate a collective response of colony to the disruption of individual biochemical and structural homeostasis. In essence, our results demonstrate that the honeybee is a compelling supplementary model that offers a promising opportunity to understand both socio-behavioral and molecular mechanisms of cocaine action, with potential implications for drug impact and addiction research. • A single dose of cocaine significantly affects the level of biogenic amines in bees. • Cocaine affects also antioxidant markers, vitellogenins and citrate synthase. • Cocaine induces mitochondrial abnormalities in thoracic muscles. • Cocaine social effect manifests itself through modulation of vibroacoustic signals. • Bees appear to be an alternative model to study mechanisms of cocaine actions.
  • Telomeres and telomerase: active but complex players in life-history decisions
    Radmila Čapková Frydrychová, Barbora Konopová, Vratislav Peska, Miloslav Brejcha, Michala Sábová
    Biogerontology, 2024
  • Seasonal changes in ultrastructure and gene expression in the fat body of worker honey bees
    Miloslav Brejcha, Daniela Prušáková, Michala Sábová, Vratislav Peska, Jan Černý, Dalibor Kodrík, Barbora Konopová, Radmila Čapková Frydrychová
    Journal of Insect Physiology, 2023
  • Seasonality in telomerase activity in relation to cell size, DNA replication, and nutrients in the fat body of Apis mellifera
    Justina Koubová, Michala Sábová, Miloslav Brejcha, Dalibor Kodrík, Radmila Čapková Frydrychová
    Scientific Reports, 2021
    In honeybees (Apis mellifera), the rate of aging is modulated through social interactions and according to caste differentiation and the seasonal (winter/summer) generation of workers. Winter generation workers, which hatch at the end of summer, have remarkably extended lifespans as an adaptation to the cold season when the resources required for the growth and reproduction of colonies are limited and the bees need to maintain the colony until the next spring. In contrast, the summer bees only live for several weeks. To better understand the lifespan differences between summer and winter bees, we studied the fat bodies of honeybee workers and identified several parameters that fluctuate in a season-dependent manner. In agreement with the assumption that winter workers possess greater fat body mass, our data showed gradual increases in fat body mass, the size of the fat body cells, and Vg production as the winter season proceeded, as well as contrasting gradual decreases in these parameters in the summer season. The differences in the fat bodies between winter and summer bees are accompanied by respective increases and decreases in telomerase activity and DNA replication in the fat bodies. These data show that although the fat bodies of winter bees differ significantly from those of summer bees, these differences are not a priori set when bees hatch at the end of summer or in early autumn but instead gradually evolve over the course of the season, depending on environmental factors.