Tutorial 18: Limbic System

Intro | Amygdala | Mammillary Body | Olfactory Bulb | Cingulate Gyrus | Dentate Gyrus | Fornix | Hippocampus | Septum | Thalamus

Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test
Part 3: Multiple-Choice Self-Test

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The Limbic System is a network of connected structures that lies roughly along the border between the cerebral cortex and deeper structures. These regions, linked within the central nervous system, work together to affect a wide range of behaviors including emotions, motivation, and memory. Figure 18 identifies the principle limbic structures and describes the primary functions of each.


The limbic structures were first "identified" by J.W. Papez in 1937 when he proposed that the hypothalamus and several other subcortical structures were connected together forming a "circuit" responsible for the control of emotions. This proposal was based on the finding that each of the limbic structures respond to odors, taste, and painful stimuli by evoking intense emotional reactions. These senses are slow to respond and resolve and are only vaguely localized in space, characteristics shared with emotional responses. Papez's theory was later revised by P. MacLean based on the results of brain damage to these structures and coined the term currently in use; the "limbic (meaning limbus or border) system". MacLean observed that people with temporal lobe epilepsy or damage to this region may experience aggressive impulses, fear, feelings of dissociation similar to multiple personality disorder (now known as dissociative identity disorder), uncontrollable laughter, states of existential bliss, and sexual arousal. MacLean distinguished three limbic circuits based on function; emotions related to self-preservation (amygdala and hippocampus), emotions related to pleasure (cingulate gyrus and septum), and emotions related to social cooperation (parts of the hypothalamus and anterior thalamus).

Suggestions for further study


Horgan, J. (1994, May), Neural eavesdropping, Scientific American, 270(5), 16.

Kalin, N.H. (1993, May). The neurobiology of fear. Scientific American, 94-101.

Kandel, E.R. & Hawkins, R.D. The biological basis of learning and individuality. Scientific American, 267(3), 78-86.

Kevles, B.H. & Kevles, D.J. (1997, October). Scapegoat biology. Discover, 18(10), 59-62.
Genetic contributions to & biological explanations of aggression.

LeDoux, J.E. (1994, June). Emotion, memory and the brain. Scientific American, 50-57.

LeVay, S, Hamer, D.H. (1994, May). Evidence for a biological influence in male homosexuality, Scientific American, 270(5), 44-49.

Menaker, M. (1972, March). Nonvisual light reception, Scientific American, 226(3), 22-29.

Mishkin, M. Appenzeller, T. (1987, June). The anatomy of memory, Scientific American, 256(6), 80-89.

Nemeroff, C.B. (1998, June). The neurobiology of depression. Scientific American, 42-49.

Olton, D.S. (1977, June). Spatial memory, Scientific American, 236(6), 89-94, 96, 98.

Vertosick, F.T. (1997, October). Lobotomy's back. Discover, 18(10), 66-72.
New surgical techniques bring back the cingulotomy for psychiatric treatment.


(Estrogen's Influence on the Brain)
from Society for Neuroscience - Brain Briefings, 1997.

(Medial Temporal Lobe & Limbic System)
Washington University School of Medicine - Neuroscience Tutorial

(Fear and the Amygdala)
from Society for Neuroscience - Brain Briefings, 1998.

(Gender and the Brain)
from Society for Neuroscience - Brain Briefings, 1998.

(Hypothalamus and the Autonomic Nervous System)
Washington University School of Medicine - Neuroscience Tutorial

(Weight Control and Obesity)
Society for Neuroscience - Brain Briefings, 1997.

(The Virtual Hospital - The Human Brain)
Williams, Gluhbegovic & Jew, University of Iowa
A superb detailed atlas of human brain dissections.

(The Whole Brain Atlas - Harvard University)
Johnson & Becker, Harvard University and Massachusetts Inst. of Technology

(The Digital Anatomist Project)
University of Washington, On-line Interactive Atlas including 3-D computer graphics, MRI scans and tissue sections.