The rat is one of the species most commonly used in laboratory practice. Numerous publications concerning various aspects of morphology and physiology are based on the results obtained in this species. It make these results comparable and under some precautions enables to transpose into the relationships observed in humans. Each experimental project must obtain the permission of the Local Ethical Committee, as well as comply with the regulations of the European Communities Council, outlined in the “European Convention for the protection of vertebrate animals used for experimental and other scientific purposes”. Adequate pre-operative care can eliminate or reduce the incidence of many complications, which may occur during anaesthesia. General anaesthesia in experimental practice can be achieved using a variety of drugs and ways of administration, among others inhalational or intravenous. The side effects of anaesthetic agents can be reduced in this way. Knowledge of the effect of anaesthetics on the cerebral circulation, metabolism and intracranial pressure in both normal and pathological conditions is crucial for neurobiological purposes. Many anaesthetic agents depress respiration, which can result in hypoxia, hypercapnia and acidosis. To maintain blood carbon dioxide and oxygen concentration in the physiological range, it is necessary to apply tracheal intubation and artificial ventilation. However, even when using sophisticated equipment, the role of basic clinical observation, such as the colour of the blood shed in the operation field, breathing depth and frequency, cannot be overestimated. The importance of monitoring mean arterial blood pressure and intracranial pressure in experiments on the central nervous system is fundamental. Special attention should be paid to controlling the temperature and monitoring the fluid balance. Appropriate postoperative care can have a decisive influence on the final results of the research.