Neuronal activity of raphe nuclei of the brain stem in the cat

1. The purpose of these experiments was to compare effects of electrical stimuli applied in two regions of the brain stem that are the sites of origin of descending bulbospinal systems; namely, the nucleus gigantocellularis of Brodal (7) and the nucleus raphe magnus, on the responses of lumbosacral spinothalamic neurons to mechanical stimuli. 2. In cats anesthetized with alpha-chloralose, stimulating in either of these structures with single pulses of current while the spinothalamic neuron was tonically activated by a sustained mechanical pressure resulted in an increase in the excitability of the cell followed by a prolonged suppression of its impulse activity. 3. For different neurons, the latency of the excitation ranged from 4 to 18 ms following the brain stem stimulus, while the latency of the suppression ranged from 16 to 34 ms. 4. In general, the effects of stimulating in the reticular formation and in the raphe nuclei were similar. although quantitative differences were found in the effects of each on different spinothalamic neurons. On the basis of these two studies, it is argued that the reticulospinal and raphe-spinal systems exert qualitatively similar effects on the responses of spinothalamic neurons evaluated in this experiment. 5. A comparison of the magnitudes of the suppression phase evoked from several different sites in the ipsilateral reticular formation and nucleus raphe magnus suggests that the descending systems arising from both these structures may be quite heterogeneous. 6. Stimulation of both regions of the brain stem produced a much greater suppression of the response of the spinothalamic neurons to slowly changing or sustained mechanical stimuli than to transient stimuli. It is suggested that the effects of descending systems arising both in the raphe nuclei and in the reticular formation on the responses of spinothalamic neurons to a mechanical stimulus are at least as dependent on the time course of the mechanical stimulus as they are on its intensity.

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The raphe nuclei of the rabbit brain stem

The Journal of Comparative Neurology ◽

10.1002/cne.901870112 ◽

1979 ◽

Vol 187 (1) ◽

pp. 199-243 ◽

Cited By ~ 59

Author(s):

David L. Felten ◽

John P. Cummings

Keyword(s):

Brain Stem ◽

Raphe Nuclei ◽

Rabbit Brain ◽

Raphé Nuclei

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Spinal projections from the lower brain stem in the cat as demonstrated by the horseradish peroxidase technique. II. projections from the dorsolateral pontine tegmentum and raphe nuclei

Brain Research ◽

10.1016/0006-8993(79)90980-6 ◽

1979 ◽

Vol 176 (2) ◽

pp. 215-231 ◽

Cited By ~ 138

Author(s):

Masaya Tohyama ◽

Kazuya Sakai ◽

Monique Touret ◽

Denise Salvert ◽

Jouvet Michel

Keyword(s):

Horseradish Peroxidase ◽

Brain Stem ◽

Raphe Nuclei ◽

Pontine Tegmentum ◽

Peroxidase Technique ◽

Lower Brain Stem ◽

Raphé Nuclei

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In vivo inhibition of neuronal activity in the rat ventromedial prefrontal cortex by midbrain-raphe nuclei: role of 5-HT1A receptors

Neuropharmacology ◽

10.1016/s0028-3908(03)00139-4 ◽

2003 ◽

Vol 45 (1) ◽

pp. 72-81 ◽

Cited By ~ 76

Author(s):

M Hajós

Keyword(s):

Prefrontal Cortex ◽

Neuronal Activity ◽

Ventromedial Prefrontal Cortex ◽

Raphe Nuclei ◽

Midbrain Raphe Nuclei ◽

Raphé Nuclei

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Neuronal activity in the brain stem reticular formation during performance of a “go-no go” visual attention task in the monkey☆

Experimental Neurology ◽

10.1016/0014-4886(78)90170-x ◽

1978 ◽

Vol 60 (1) ◽

pp. 83-95 ◽

Cited By ~ 17

Author(s):

Eva Bakay Pragay ◽

Allan F. Mirsky ◽

Constance L. Ray ◽

David F. Turner ◽

Carol V. Mirsky

Keyword(s):

Visual Attention ◽

Brain Stem ◽

Reticular Formation ◽

Neuronal Activity ◽

Attention Task ◽

The Brain

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The Lateral Habenula: No Longer Neglected

CNS Spectrums ◽

10.1017/s1092852900016710 ◽

2008 ◽

Vol 13 (6) ◽

pp. 484-489 ◽

Cited By ~ 103

Author(s):

Stefanie Geisler ◽

Michael Trimble

Keyword(s):

Cross Talk ◽

Brain Structure ◽

Clinical Relevance ◽

Raphe Nuclei ◽

Dopamine System ◽

Lateral Habenula ◽

Nuclear Complex ◽

The Cross ◽

Raphé Nuclei ◽

The Brain

In this contribution to the CNS Spectrums neuroanatomy series, Stefanie Geisler, MD, discusses the lateral habenula (LHb). This nuclear complex is one of the areas of the brain that forms part of the cross-talk between limbic fore-brain and some important ascending modulatory pathways. Situated at the caudal end of the dorsal diencephalon and classically regarded as projecting largely to the brainstem, including the serotoninergic raphe nuclei, the LHb receives afferents from widespread forebrain areas. Therefore, the LHb is able to influence serotonin tone in the brain, and has long interested neuroanatomists as a potential limbic-motor interface. Nonetheless, the LHb was not much discussed outside neuroanatomical circles until recently, when it was discovered that its impact on the mesotelencephalic dopamine system is probably much greater than had been assumed. The LHb has become a hot topic. This article-addresses these developments and emphasizes the clinical relevance of this interesting brain structure.

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