Anesthesia: From the point of view of caring for animals, in order to alleviate their experimental pain, physical or chemical methods are used to make animals temporarily lose pain or feel dull, reduce their struggle and keep quiet to ensure experimental operation.

Classification of anesthesia: according to the scope of anesthesia, it is mainly divided into general anesthesia and local anesthesia, and general anesthesia is divided into inhalation anesthesia and non-inhalation anesthesia. 1. General anesthesia: inhalation anesthesia: also known as gas anesthesia, inhaling volatile or gas anesthetics from animal respiratory tract to produce anesthetic effect; Anesthetics such as isoflurane and sevoflurane are usually used in experiments in rats and mice.

Non-inhalation anesthesia: injection anesthesia, including intramuscular injection, intraperitoneal injection and intravenous injection. Avermectin, pentobarbital sodium, chloral hydrate and ketamine are commonly used in the experiments of rats and mice. 2. Local anesthesia refers to blocking the sensory nerve conduction function of a certain part of the body with anesthetics, while the motor nerve conduction remains intact or blocked to varying degrees.