Molecular cytogenetics and in situ hybridization (ISH) methods have revolutionized the understanding of the structure, function, organization and evolution of genes and genomes, and allow identifying the presence and expression of pathogens within the affected cells. ISH is a technique that combines molecular biology and histochemical techniques to study gene expression in tissue sections and cytological preparations, so that the DNA or RNA can be quickly located in a specific cell. ISH locates the specific sequence of an in situ gene and displays the result of the expression of said gene while preserving the integrity of the cell in the surrounding tissue, which allows for significant anatomical interpretations. This technique is the result of a reaction in which a labeled probe binds to a nucleic acid sequence, which is complementary. ISH methods are applicable in clinical research and diagnostic pathology, being widely used to search for chromosomal gene expression or to detect the presence of bacteria or viruses in infected tissues, as it makes it possible to differentiate pollutants from real pathogens in an infectious process.

The electroencephalography has come to be a useful diagnostic aid in known or suspected cerebral disorders, the purpose of this study was to assess digital and quantitative electroencephalography in healthy dogs under propofol and tiopenthal anaesthesia, in order to determine the influence of these agents on the EEG and to obtain objective guidelines for diagnostic electroencephalographic recordings and interpretation. Thirteen dogs of different race, sex, origin, within ten months and seven years of age were used, during 23 sessions of which, eleven were with propofol, 10 with tiopenthal and 3 for testing. The analysis and interpretation of the EEG records was based on a preliminary visual examination where artifacts, normal background rhythms and transient events on sleeping dogs were assessed. When digital and spectral analysis were performed, the basic pattern found was characterized by spindles, k-complexes and vertex sharp transients. The EEG was characterized by the prevalence of slow rhythms è and low intensity á, both in amplitude spectrum analysis, while ä rhythms were poorly represented and fast â rhythms were completely absent. The statistic parametric and no parametric analysis showed that there is no evident influence of the anesthetic agents on the EEG or the evoked potentials. The present study has shown that the anesthetics used, on low doses, maintained the electroencephalographic isoelectricity. The use of digital and spectral analysis gives information on the frequency content of the bio-electrical activity, deûns the distribution of the frequency bands under a standardized anesthetic protocol and determines the plane of anesthesia and sleep stage, which is useful during surgical anesthesia monitoring.