Location and Structure of the Septal Area
- The septal area is located in the lower, posterior part of the medial surface of the frontal lobe.
- It refers to the nearby septum pellucidum.
- The septal area consists of the lateral septum and medial septum.
- The septal nuclei, composed of medium-size neurons, are located in this area.
- The septal nuclei are classified into dorsal, ventral, medial, and caudal groups.
Connections of the Septal Area
- The septal nuclei receive reciprocal connections from various brain regions, including the olfactory bulb, hippocampus, amygdala, hypothalamus, midbrain, habenula, cingulate gyrus, and thalamus.
- These connections play a role in generating the theta rhythm of the hippocampus.
- The dorsal septum projects to the lateral preoptic area, lateral hypothalamus, periventricular hypothalamus, and midline thalamus.
- Fibers from the ventral half of the septum project to the hippocampal formation, thalamus, hypothalamus, and midbrain.
- Cells located in the intermediolateral septum project to the ventral hippocampus, entorhinal cortices, lateral habenular nucleus, and mediodorsal thalamic nucleus.
Functions of the Septal Area
- The septal area is considered a pleasure zone in animals.
- The septal nuclei play a role in reward and reinforcement, along with the nucleus accumbens.
- Electrical stimulation of the septal area can induce self-stimulation behavior in animals.
- The septal area has been studied in relation to reward and reinforcement in humans since the 1960s.
- The septal area has no direct relation to the sense of smell.
Functions of the Lateral Septum
- The lateral septum is involved in emotional, motivational, and spatial behavior.
- It regulates interactions between the hippocampus and other regions involved in goal-directed behavior.
- Firing of lateral septum neurons is modulated by speed, acceleration, spatial location, reward, and context.
- Inhibitory GABA and excitatory glutamate regulate lateral septum activity during social play in rats.
- Electrical stimulation of the lateral septum can induce the elevation of serum LH and FSH levels, suggesting a role in reproductive axis control.
Role of the Lateral Septum in Memory
- The role of the lateral septum in memory formation and retention is still being studied.
- Oxytocin and vasopressin administration into the lateral septum can enhance social memory formation.
- Disruption of hippocampal inputs to the lateral septum impairs fear memory formation and retrieval.
- Hippocampal projections to the lateral septum are involved in fear memory consolidation.
- Further studies are needed to fully understand the role of the lateral septum in memory processes.
The septal area (medial olfactory area), consisting of the lateral septum and medial septum, is an area in the lower, posterior part of the medial surface of the frontal lobe, and refers to the nearby septum pellucidum.
| Septal area | |
|---|---|
 Lateral and medial septal nuclei in the septal area of the mouse brain | |
| Details | |
| Identifiers | |
| Latin | nuclei septales |
| MeSH | D012686 |
| NeuroNames | 259 |
| TA98 | A14.1.09.266 |
| TA2 | 5548 |
| FMA | 61845 |
| Anatomical terms of neuroanatomy | |
The septal nuclei are located in this area. The septal nuclei are composed of medium-size neurons which are classified into dorsal, ventral, medial, and caudal groups. The septal nuclei receive reciprocal connections from the olfactory bulb, hippocampus, amygdala, hypothalamus, midbrain, habenula, cingulate gyrus, and thalamus. The septal nuclei are essential in generating the theta rhythm of the hippocampus.
The septal area (medial olfactory area) has no relation to the sense of smell, but it is considered a pleasure zone in animals. The septal nuclei play a role in reward and reinforcement along with the nucleus accumbens. In the 1950s, Olds & Milner showed that rats with electrodes implanted in this area will self-stimulate repeatedly (i.e., press a bar to receive electric current that stimulate the neurons). Experiments on the septal area of humans have taken place since the 1960s.
