Reticular formation, monoaminergic systems

Question 1

I. RETICULAR FORMATION
1. How is reticular formation formed?

Answer 1

• The central portion of the medulla and the pontine and midbrain tegmentum are populated with interconnected groups of neurons, which form the reticular formation.
• It is a diffuse system (not definitely localized).

Question 2

I. RETICULAR FORMATION
2. What are the 3 large components of nervous system?

Answer 2

The 3 large components of the nervous system: the somatic, the visceral and the connectivity of the organs of special senses merge in the reticular formation
-> All these systems provide afferentation to the reticular nuclei, thus, it is involved in practically all kinds of neuronal events.

Question 3

I. RETICULAR FORMATION
3. What do Major efferent projections from the reticular formation and raphe nuclei lead to?

Answer 3

Major efferent projections from the reticular formation and raphe nuclei lead to the
cerebral cortex (ascending reticular activating system), to the cerebellar cortex and to the spinal cord.

Question 4

I. RETICULAR FORMATION
4. What are vital centers?

Answer 4

Loose nuclei are called vital centers and send projections to other parts of the brain. These are essential to control the respiration and the cardiovascular function in our body.

Question 5

I. RETICULAR FORMATION
5A. What are the 3 main respiratory groups regarding respirations?

Answer 5

1. Dorsal respiratory group (DRG) found in the solitary tract nucleus.
2. Ventral respiratory group (VRG)
3. Pontine respiratory group (PRG)

Question 6

I. RETICULAR FORMATION
5B. What is the role of Dorsal respiratory group (DRG)?

Answer 6

Dorsal respiratory group (DRG) found in the solitary tract nucleus. Responsible for
initiation of inhalation and setting the rate of respiration

Question 7

I. RETICULAR FORMATION
5C. What is the role of Ventral respiratory group (VRG) ?

Answer 7

• Ventral respiratory group (VRG) maintains the correct rhythm of expiration and
  inspiration.
• Represented by a region for expiration and a special region for inspiration (Bötzinger and pre-Bötzinger complex) which launch APs between each other.
• Also regulate the rhythm of respiration

Question 8

I. RETICULAR FORMATION
5C. What is the role of Ventral respiratory group (VRG) ?

Answer 8

Pontine respiratory group (PRG), also called the pneumotaxic region, is important in switching off the inspiration, thereby limiting the volume of air that can get in the lung
=> PRG is found in the pons, while the DRG and VRG are found in the medulla
=> We also have a nuclear region for vasomotor control in the pons
=> Around the pneumotaxic region, we have the acoustic and vestibular orientation in space
=> In the mesencephalon, we have a nuclear region for visual orientation

Question 9

II. MONOAMINERGIC SYSTEMS
1. What is the characteristics of monoaminergic system?

Answer 9

The reticular formation also makes place for different monoaminergic projections.

Neurons have different monoamines as their neurotransmitters.

For example: catecholamines –
mainly the noradrenaline, dopamine and adrenaline. Another monoamine which is not a catecholamine, is serotonin. Only exception is acetylcholine, which is NOT a monoamine.

Question 10

II. MONOAMINERGIC SYSTEMS
2. What are the 3 groups of nuclei of reticular formation?

Answer 10

1. Median nuclei group located in the middle
2. Paramedian nuclei group is located laterally to the median nuclei group
3. The lateral nuclei

Question 11

II. MONOAMINERGIC SYSTEMS
2. Describe the Median nuclei group located in the middle

Answer 11

Question 12

II. MONOAMINERGIC SYSTEMS
3. Describe the Paramedian nuclei group located in the middle

Answer 12

Question 13

II. MONOAMINERGIC SYSTEMS
4. Describe the lateral nuclei

Answer 13

Restricted to the brainstem and form connections
between different parts of
the reticular formation