The effect of caffeine on alpha activity in the cerebral cortex of rats in different models of depression

Valeriia Mizin — 2025-04-10

The aim of the study is to determine changes in the power spectral density of the alpha-like rhythm of the cerebral cortex in models of contagious depression and chronic unpredictable stress, as well as to study the effect of caffeine on these indicators.

Materials and methods. The study was conducted on white sexually mature male rats weighing 230–300 grams. Six groups were formed according to the type of depression and caffeine consumption. The electroencephalographic method was used, and the power spectral density analysis in the alpha range was performed to assess the depressive-like state and the effect of caffeine. The power spectral density of alpha activity (8–12 Hz) was assessed in the cortical zones of male rats: Fp1, Fp2, F3, F4, P3, P4, O1, O2.

Results. The assessment of the power spectral density of activity in the 8–12 Hz range in the Fp1 and Fp2 points showed a statistically significant interaction between the type of depression and the effect of caffeine. In the Fp2 area, the effect of depression was more noticeable. In both types of depression, a significant increase in the power spectral density in the 8–12 Hz range was observed in the F3 and F4 areas. The administration of caffeine reduced these indicators, but did not ultimately reduce the effects of depression. In the P3 and P4 points, depression has no significant impact on the power spectral density, while caffeine reduces the power of the alpha range in both hemispheres. Caffeine reduced the power spectral density in all groups in the occipital areas (points O1 and O2). In contrast, in animals with depressive states, the effect of caffeine was only partial.

Conclusions. Depression of different genesis affects different parts of the brain differently. Alpha spectral power density increases in frontal and occipital regions and decreases in the prefrontal cortex. Caffeine significantly reduces power spectral density in occipital, frontal, and parietal areas

Antimycobacterial activity of new aryloxyethoxy-dialkylaminopropanol derivatives against reference strains of nontuberculous mycobacteria

Volodymyr Nastenko — 2025-04-10

Objective. To evaluate the in vitro antimycobacterial activity of novel quaternary ammonium salts, derived from alkyl(aryloxyethoxy)dialkylaminopropanol against reference strains of nontuberculous mycobacteria (NTM).

Materials and Methods. A total of 52 synthesized compounds, obtained via phase-transfer catalysis, were studied,. The activity was assessed in two stages: initial screening using the agar diffusion method (well method), followed by minimum inhibitory concentration (MIC) determination through serial dilution. Primary testing was performed on Mycobacterium smegmatis, followed by evaluation on M. terrae, M. avium, and M. B5 using the proportion method on Löwenstein–Jensen medium. Compounds were tested at three concentrations: K-I (MIC for M. smegmatis), K-II (10×MIC), and K-III (100×MIC).

Results. Ten compounds with the highest activity against M. smegmatis were identified during the screening stage. The most active was Kc12 (MIC – 0.22±0.02 µg/mL). Other active compounds included: Kc16, Kc13, Kc15, Kp15, Kp20, Kp18, Kc22, Kc14, and Kp16. Among the NTM strains, M. terrae and M. B5 were the most sensitive. At K-II, compounds Kc12, Kc13, Kc15, Kc16, Kc22, and Kp18 inhibited bacterial growth by more than 95 %. Kc15 demonstrated the efficacy comparable to rifampicin, while Kp18 and Kc12 surpassed streptomycin. M. avium exhibited resistance, with growth suppression below 5 %, observed only at K-III in a few compounds. The least active was Kp20.

Conclusions. Ten promising compounds were identified, notably Kc12, Kc15, Kp18, Kc16, and Kc22, whose activity exceeded that of streptomycin and approached rifampicin in some cases. The findings highlight the potential of these compounds for further preclinical development in the treatment of NTM infections

ScienceRise: Biological Science

The effect of caffeine on alpha activity in the cerebral cortex of rats in different models of depression

Antimycobacterial activity of new aryloxyethoxy-dialkylaminopropanol derivatives against reference strains of nontuberculous mycobacteria