The Papez circuit, or medial limbic circuit, is a neural circuit for the control of emotional expression. In 1937, James Papez proposed that the circuit connecting the hypothalamus to the limbic lobe was the basis for emotional experiences. Paul D. MacLean reconceptualized Papez's proposal and coined the term limbic system. MacLean redefined the circuit as the "visceral brain" which consisted of the limbic lobe and its major connections in the forebrain – hypothalamus, amygdala, and septum. Over time, the concept of a forebrain circuit for the control of emotional expression has been modified to include the prefrontal cortex.
In a dissected brain, the inferior medial view shows the curved shape of the structures of the Papez circuit in the brain.
A heuristic model of the neural pathway of the Papez circuit shows the connections between its different parts.
Compared to a healthy individual, Alzheimer's patients experience significantly more brain loss. The neurodegenerative effects of the disease can be seen by comparing the brains of a healthy individual and an Alzheimer's patient.
Neuroscientist Paul D. MacLean is famous for his work on the limbic system and its evolutionary history.
A neural circuit is a population of neurons interconnected by synapses to carry out a specific function when activated. Multiple neural circuits interconnect with one another to form large scale brain networks.
From "Texture of the Nervous System of Man and the Vertebrates" by Santiago Ramón y Cajal. The figure illustrates the diversity of neuronal morphologies in the auditory cortex.
Proposed organization of motor-semantic neural circuits for action language comprehension. Gray dots represent areas of language comprehension, creating a network for comprehending all language. The semantic circuit of the motor system, particularly the motor representation of the legs (yellow dots), is incorporated when leg-related words are comprehended. Adapted from Shebani et al. (2013)
Model of a neural circuit in the cerebellum
