The anterior olfactory nucleus lays between the olfactory bulb and piriform cortex and relays information between them. The anterior olfactory nucleus is also known as the olfactory peduncle but it is only a component of it. The anterior olfactory nucleus has reciprocal connections with the olfactory bulb. It also transmits information between left and right piriform cortices and also the left and right olfactory bulbs. Instead of being named the olfactory cortex, it is called nucleus because there are only two layers. The anterior olfactory nucleus is divided into the pars externa and pars cruralis.