lateral reticular nucleus (LRN)

The term lateral reticular nucleus (LRN) refers to a group of cells defined on the basis of Nissl and cholinergic stains, that is located ventrolaterally in the medullary reticular formation (MRF) of the human ( Carpenter-1983, Paxinos-2012 ) ), the macaque ( Martin-2000 ), the rat ( Swanson-2004 ) and the mouse ( AMBA-2024 ). It is divided into a magnocellular part of the lateral reticular nucleus (LRNmc)and parvicellular part of the lateral reticular nucleus (LRNpc) (not to be confused with the parvicellular reticular nucleus (PCR)). The lateral reticular nucleus as defined by Nissl stain is not subdivided in most textbooks and Brain atlases of primates. The A1 cell group of noradrenergic neurons is found in its vicinity ( Dahlstrom-1964; Felten-1983 ). Functionally it belongs to the postcerebellar and precerebellar nuclei of the behavior control column ( Swanson-2004 ). Paxinos-2012 segments the LRN into three parts based on stains for acetylcholine (ACH) and norepinephrine (NE) in addition to Nissl substance. They include LRNpc, the lateral reticular nucleus, subtrigeminal part of Paxinos (LRNs5), which has, in addition to the cholinergic cells found in all of the LRN, noradrenergic cells of the A1 cell group; and, by far the largest part of the remaining LRNmc, the lateral reticular nucleus, proper part of Paxinos (LRNpr). Brain atlases in which LRN is segmented according to this scheme include those of the human ( Paxinos-2012 ), macaque ( Paxinos2009a ), rat ( Paxinos 2009b ) and mouse ( Franklin-2008 ). Updated 20 Jan 2026 )

Also known as: lateral reticular nucleus, Nucleus reticularis lateralis, Nucleus reticularis lateralis (medullae), Nucleus lateralis medullae oblongatae, lateral reticular nucleus (medulla)

NeuroNames ID: 727

All Names & Sources

Showing 15 synonym(s)

Language
Name
Source
English
lateral reticular nucleus
English
lateral reticular nucleus
English
lateral reticular nucleus
English
lateral reticular nucleus (medulla)
Species With The Structure
Equivalent By Human Macaque Rat Mouse
Topology Has The Structure Has The Structure Has The Structure Relevant Data Not Located

Showing 7 record(s)

Basis
Has Equivalent
Organism
Their Name
Source
Topology
Yes
lateral reticular nucleus
Topology
Yes
lateral reticular nucleus (medulla)
Topology
Yes
Nucleus reticularis lateralis (medullae)
Topology
Yes
lateral reticular nucleus
Topology
Yes
Nucleus reticularis lateralis
Topology
Yes
Nucleus lateralis medullae oblongatae
Topology
Yes
lateral reticular nucleus
Models Where It Appears
Structural CNS Model - Macaque

Brain structures of the macaque are illustrated in BrainInfo’s NeuroMaps macaque brain atlas. Structures are grouped by proximity in a hierarchy corresponding to the central nervous system hierarchy of NeuroNames ( Bowden-1995 Martin-2000 ). Structures in the NeuroMaps atlas are based on the segmentation of an MRI of the brain of a 3-year old male rhesus macaque (Macaca mulatta). The atlas is most useful for targeting structures for implantating electrodes and chemtrodes. Updated 29 Oct 2025.

Functional CNS Model - Rat

The Functional CNS Model - Rat (FMrat) ( Swanson-2004) is one of three hierarchical models representing the internal organization of the central nervous system (CNS). The others are the Structural CNS Model - Human (SThmn) and the Functional CNS Model - Human (FMhmn). The FMrat model represents the basic organization of the mouse ( Hof-2000 AMBA-2024 ) and, presumably, other rodents. Functional CNS models differ from structural models in that structures are defined and named by connectivity rather than by proximity to other structures at the same level. Functional models are more useful for representing longitudinal components of are grouped based on information drawn from multiple neuroscientific disciplines. such as connections, neurochemical characteristics, and role in physiogical and behavioral processes. While the Functional Model was developed primarily for an atlas of the rat brain ( Swanson-2004 ), the hierarchical organization of structures is for the most part applicable to the human, macaque, mouse and other mammalian brains as well. Structures at lower levels of the Functional CNS hierarchy are largely the same as in the Classical and Developmental Models, i.e., they were originally identified by stains for gray matter (Nissl substance) and white matter (myelin). At the next higher level they are grouped into basic connectional and functional systems of the CNS, such as the subcortical sensory systems, the brainstem motor system and the behavioral state system. At the highest levels CNS structures are grouped on the basis of dissection and embryologic precursors into cerebrum ( cerebral cortex and cerebral nuclei ), cerebellum, and cerebrospinal trunk.