A haloalkane (also known as halogenoalkane or alkyl halide) is a group of chemical compound that consists of an alkane with one or more halogens attached to it.
Chloroform is a haloalkane which functions as an anesthetic.
The exact manner in which anesthetics works is, for the most part, still uncertain at the cellular and molecular levels. There are two big theories, however, about how this might work. The Meyer Overton theory states that anesthetic chemicals dissolve within the membranes of cells and then causes the structures of these cells to be distorted. This, consequently, impairs the ability of nerve signals to be carried along nerve cells. A second theory states that anesthetics interact with specific proteins, such as neurotransmitter receptors and ion channels, and change their structures, thereby, affecting their action.
One of the mechanisms describing how chloroform, specifically, works is that it increases the movement of potassium through potassium ion channels in nerve cells. Chloroform has been shown to activate these channels, and this can lead to hyperpolarization of the membranes, which happens to make nerve cells less "excitable," or less able to carry an electrical signal. This can either prevent the release of neurotransmitters, or prevent the response caused by neurotransmitters, or both. Also, chloroform, as well as most of the anesthetic chemicals, can work by increasing the level of the neurotransmitter gamma-aminobutyric acid (GABA) in the brain. GABA is an inhibitory neurotransmitter, which means that it slows down the conduction of nerve signals. The more GABA that's present, the less efficient the nervous system might be.
However, owing to its toxic effects, Chloroform is not currently used as a surgical anesthetic.