Reticular formation

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The reticular formation the oblong section.

The reticular formation (RF) is a phylogenetically old network of interconnected neurons. It permeates the brainstem, continues into the thalamus and hypothalamus, and connects caudally to the propriospinal spinal network.[1]

It begins as a band of grey matter in the cervical part of the spinal cord. A large portion are interneurons.


-sensory, motor and autonomic function, complex reflexes

- control centre for respiration, cardiovascular system, vasomotor, sleep, wakefulness

- ARAS - ascending reticular activating system - maintenance of wakefulness, circadian cycle (24 hour)

- reticulospinal system - motor functions

3 main zones of nuclei: a) nuclei raphes b) medial region c) lateral region


  1. At the midline of the pontus (nuclei raphe),
  2. lateral magnocellular RF (mostly efferent),
  3. at the border of the pontus and oblongata, gigantocellular RF + central reticular nucleus + parvocellular RF (mostly afferent) extending into the mesencephalon,
  4. in the oblongate nuclei paramedian (connecting the cerebellum) + lateral (connecting the cerebellum and spinal cord),
  • function: gigantocellular nucleus - standing + walking, nucleus in lat. pontus - bladder control, central nuclei of the oblongata - circulation + respiration

Nuclei raphes

- along the midline of the brainstem, different species - heterogeneous, produce neurotransmitters such as serotonin, GABA, glycine, neuropeptides, substance P, cholecystokinin

Medial region of nuclei

- source of efferent pathways - effector part

Lateral region of nuclei

- afferent fibres, sensory part

- of the spinal cord, rhombencephalon, cranial nerve nuclei, mesencephalon, cortex, basal nuclei

RF neurons produce:

  • serotonin - with a maximum in the ncl. raphe in the oblongata, pontus and mesencephalon,
  • dopamine - in the tegmentum of the mesencephalon,
  • noradrenaline - in the pontus - locus coeruleus + laterobasally in the wall of the IVth ventricle,
  • adrenaline in the oblongata,
  • aminergic neurons controlling sleep and wakefulness, attention and mood, with a close relationship to sensation,
  • serotonin + noradrenaline in depression, dopamine in schizophrenia[1].

Ascending reticular formation ARAS[edit | edit source]

  • receives all stimuli from all afferent sensory + sensory pathways (exteroreceptors, proprioceptors, receptors from internal organs),
  • connected to the cerebral cortex,
  • its constant activity ensures wakefulness (ARAS - the part of the RF that influences consciousness and wakefulness by its action on the cerebral cortex)
  • when disturbed, impaired consciousness (up to coma)[1].

Descending RF[edit | edit source]

  1. Facilitatory RF - has constant activity, in the rostral region of the trunk,
  2. inhibitory RF - no spontaneous activity, controlled by cortex + basal ganglia,

Both of these parts are related to momentum, especially γ-motoneuron excitability[1].

Links[edit | edit source]

Related articles[edit | edit source]

References[edit | edit source]

  1. a b c d SEIDL, Zdeněk – OBENBERGER, Jiří. Neurologie pro studium i praxi. 2. edition. Grada Publishing, 2004. ISBN 80-247-0623-7.