In the study of fornix stimulation in AD patients, volume changes of fornix and mammillary bodies were highly correlated with hippocampal volume change after fornix stimulation, which strongly suggests the critical role of Papez circuit
in memory function regulation.
In the Papez circuit, the Ca1 sub-region of the hippocampus receives the information related to the memory of the entorhinal cortex and transmits it through the fornix, thus being a brain area with potential to therapeutically benefit from DBS (Hescham, Lim, Jahanshahi, Blokland, et al., 2013).
So they analysed changes in brain structure from brain magnetic resonance imaging of AD patients undergoing therapy in the aforementioned phase I trial and measured the volume of critical regions of the Papez circuit such as the hippocampus, fornix, and mammillary bodies to see if DBS made it possible to reverse the progressive neurodegeneration characteristic of the disease.
Behavioral effects of deep brain stimulation of different areas of the Papez circuit on memory- and anxietyrelated functions.
If we talked about the strengths of a woman's mind, we should mention her emotional memory, it is much stronger than that of a man's, and this is related to the Papez circuit
. It means she does not forget pain or joy, and keeps flipping through the pages of the past faster and more accurately than men.
Paul MacLean (1952) later added the amygdala, septum and prefrontal cortex to the Papez circuit
and thus established the limbic system concept as is understood today.
Contributions of James Papez (1937) through the scheme for central neural circuitry of emotion, popularly known as 'Papez Circuit
' and the detailed anatomic model developed by Paul MacLean (1949) are also some of the inevitable works in the field of emotional management.
The aim of the present study was to investigate the impact of DBS at three separate targets in the Papez circuit, including the anterior nucleus of thalamus (ANT), the entorhinal cortex (EC), and the fornix (FX), on cognitive behaviors in an Alzheimer's disease (AD) rat model.
As a major pathway of the limbic system, the Papez circuit plays a vital role in memory formation and storage.
Thus far, only a few studies have investigated the therapeutic effects of DBS in dementia-related disorders referring to the nucleus basalis of Meynert, [sup] ANT, [sup], EC [sup], and FX, [sup],, and the latter three structures are all parts of the Papez circuit. Hamani et al .
Stimulation of parts of the Papez circuit has been known to prompt effects on fear and anxiety levels due to its interconnectedness with the amygdala.
Previous animal and clinical case studies have shown that DBS of the Papez circuit may enhance spatial memory by various mechanisms.