Brodmann area 25 (BA25) is the subgenual area, area subgenualis or subgenual cingulatea area in the

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting o ...

of the

brain A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...

and delineated based on its cytoarchitectonic characteristics. It is the 25th " Brodmann area" defined by Korbinian Brodmann (thus its name). BA25 is located in the cingulate region as a narrow band in the caudal portion of the

subcallosal area The subcallosal area (parolfactory area of Broca) is a small triangular field on the medial surface of the hemisphere in front of the subcallosal gyrus, from which it is separated by the posterior parolfactory sulcus; it is continuous below with ...

adjacent to the paraterminal gyrus. The posterior parolfactory sulcus separates the paraterminal gyrus from BA25. Rostrally it is bound by the prefrontal

area 11 of Brodmann Brodmann area 11 is one of Brodmann's cytologically defined regions of the brain. It is in the orbitofrontal cortex which is above the eye sockets (orbitae). It is involved in decision making and processing rewards, planning, encoding new infor ...

History

Brodmann described this area as it is labeled now in 1909. Originally in 1905, Brodmann labeled the area as part of area 24. In 1909, he divided the area into area 24 and 25.

Function

This region is extremely rich in

serotonin transporter The serotonin transporter (SERT or 5-HTT) also known as the sodium-dependent serotonin transporter and solute carrier family 6 member 4 is a protein that in humans is encoded by the SLC6A4 gene. SERT is a type of monoamine transporter protein tha ...

s and is considered as a governor for a vast network involving areas like

hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus ...

and brain stem, which influences changes in appetite and sleep; the

amygdala The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex ver ...

and insula, which affect the mood and anxiety; the

hippocampus The hippocampus (via Latin from Greek , 'seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic syste ...

, which plays an important role in memory formation; and some parts of the

frontal cortex The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove be ...

responsible for self-esteem.Faulty Circuits
, ''Scientific American'', April 2010 This region is particularly implicated in the normal processing of sadness.

Involvement in depression

The subcallosal cingulate gyrus CG25 which consists of BA25 as well as parts of BA24 and BA32 has been implicated as playing an important role in major depression and has been the target of

deep brain stimulation Deep brain stimulation (DBS) is a neurosurgical procedure involving the placement of a medical device called a neurostimulator, which sends electrical impulses, through implanted electrodes, to specific targets in the brain (the brain nucleus ...

to treat the disorder. One study found that BA25 is metabolically overactive in treatment-resistant depression. A different study found that metabolic hyperactivity in this area is associated with poor therapeutic response of persons with

major depressive disorder Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Intro ...

to cognitive-behavioral therapy and

venlafaxine Venlafaxine, sold under the brand name Effexor among others, is an antidepressant medication of the serotonin-norepinephrine reuptake inhibitor (SNRI) class. It is used to treat major depressive disorder, generalized anxiety disorder, panic ...

. In 2005 Helen S. Mayberg and collaborators described how they successfully treated a number of depressed people—individuals virtually catatonic with depression despite years of talk therapy, drugs, and electroconvulsive therapy—with pacemaker-like electrodes (

) in area 25. In 2013, Walker and Lawson conducted neurofeedback research with 183 subjects experiencing drug resistant depression. The neurofeedback specifically targeted Brodmann area 25. The treatment consisted of 6 neurofeedback sessions that were 20min long each over the course of 3 weeks. 1 year after the treatment 84% of subjects experienced over a 50% reduction in depression symptoms. 9% reported a 20-50% reduction in depression symptoms. 7% reported a 0-20% improvement. 1% initially reported positive effects, but had a depression relapse before the year follow up completed. There were no side effects or complications reported from the treatment. A recent study found that

transcranial magnetic stimulation Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse gener ...

is more clinically effective treating depression when targeted specifically to Brodmann area 46, because this area has intrinsic functional connectivity (negative correlation) with area 25. Another recent study has found that the responses of area 25 to viewing sad stimuli are affected by

cortisol Cortisol is a steroid hormone, in the glucocorticoid class of hormones. When used as a medication, it is known as hydrocortisone. It is produced in many animals, mainly by the '' zona fasciculata'' of the adrenal cortex in the adrenal g ...

. This suggests that depression related changes in the activity in area 25 could be due to hypothalamic–pituitary–adrenal axis dysregulation.

Image

File:Brodmann area 25 animation small.gif, Animation. File:Brodmann area 25 medial.jpg, Medial view.

Notes and references

{{DEFAULTSORT:Brodmann Area 25 25 Serotonin Neuroscience of depression Medial surface of cerebral hemisphere

History

Function

Involvement in depression

Image

See also

Notes and references