Operating system

Principal (computer security)

Hippocampal formation

Psychology

Neuroscience

Dentate gyrus

Pyramidal cell

Nerve net

Hippocampus

Computer science

Biology

Nature Neuroscience

Hippocampal network operations supporting spatial navigation and declarative memory are traditionally interpreted in a framework where each hippocampal area, such as the dentate gyrus, CA3, and CA1, consists of homogeneous populations of functionally equivalent principal neurons. However, heterogeneity within hippocampal principal cell populations, in particular within pyramidal cells at the main CA1 output node, is increasingly recognized and includes developmental, molecular, anatomical, and functional differences. Here we review recent progress in the delineation of hippocampal principal cell subpopulations by focusing on radially defined subpopulations of CA1 pyramidal cells, and we consider how functional segregation of information streams, in parallel channels with nonuniform properties, could represent a general organizational principle of the hippocampus supporting diverse behaviors. In this Review the authors discuss recent findings supporting a framework in which the hippocampus comprises principal cell subpopulations forming nonuniform parallel circuits that are independently controlled and affect a variety of behaviors.

CA1 pyramidal cell diversity enabling parallel information processing in the hippocampus