Authors:G. Karmos, P. Lakatos, Zsuzsanna Pincze, and et al
Repetitive acoustic stimuli elicit steady-state response (SSR) in the gamma-band both in humans and in mammals. Our aim was to investigate changes of the spontaneous gamma activity and the SSR in the auditory cortex of cats in the background of an instrumental conditioning situation. Epidural electrodes were chronically implanted above the auditory neocortex. The presentation rate of the clicks varied between 20 and 65/s. Spontaneous EEG and SSR were collected in three behavioral states: in an indifferent environment, in the instrumental cage while the cat was waiting for the light CS, and when she stepped on the pedal and was waiting for the meat reward. Using different repetition rate clicks we determined which stimulus rate elicited the largest SSR in these three situations. In quiet animal the highest SSR appeared at 28-30/s. Before and during the CS the optimal stimulus rate shifted to 32-38/s. The frequency of the spontaneous gamma activity changed in parallel way depending on the situation. We conclude that both the SSR and the spontaneous gamma activity reflect resonant activity of the same neuronal circuit of the auditory cortex, and it is modulated by the motivational state of the animal.
Authors:P. Olejníková, A. Kaszonyi, M. Šimkovič, B. Lakatoš, M. Kaliňák, M. Valachovičová, and L. Birošová
The human endogenous intestinal microbiota is an essential “organ” in providing nourishment, regulating epithelial development, and instructing innate immunity. Even though lots of scientists have evaluated the content of gut microbiota from various points of view, we examined the content of intestinal microbes in the group of healthy middle aged volunteers (40–60) form Slovakia. We have compared faecal cultivable microbiota of vegetarians and omnivores. We have found that the composition of the human microbiota is fairly stable, and it seems that the major microbial groups on species level that dominate the human intestine are conserved in all individuals regardless of dietary habits. Beside the microbial content we have examined the faecal samples also for the presence of antimicrobial active compounds, potential mutagens, and faecal sterols.