Probabilistic atlas of the mesencephalic reticular formation, isthmic reticular formation, microcellular tegmental nucleus, ventral tegmental area nucleus complex and caudal-rostral linear raphe nuclei complex in living humans from 7 Tesla MRI

2021 ◽  
Author(s):  
KAVITA SINGH ◽  
María Guadalupe García-Gomar ◽  
Marta Bianciardi
Keyword(s):  
Ventral Tegmental Area ◽  
Reticular Formation ◽  
Mesencephalic Reticular Formation ◽  
Raphe Nuclei ◽  
7 Tesla ◽  
Probabilistic Atlas ◽  
Tegmental Nucleus ◽  
7 Tesla Mri ◽  
Ventral Tegmental ◽  
Raphé Nuclei

scholarly journals A probabilistic atlas of the human ventral tegmental area (VTA) based on 7 Tesla MRI data

2021 ◽  
Vol 226 (4) ◽  
pp. 1155-1167 ◽  
Author(s):  
Anne C. Trutti ◽  
Laura Fontanesi ◽  
Martijn J. Mulder ◽  
Pierre-Louis Bazin ◽  
Bernhard Hommel ◽  
...  
Keyword(s):  
Ventral Tegmental Area ◽  
Region Of Interest ◽  
Reward Processing ◽  
7 Tesla ◽  
Subcortical Structures ◽  
7 Tesla Mri ◽  
Subcortical Nuclei ◽  
Ventral Tegmental ◽  
The Brain

AbstractFunctional magnetic resonance imaging (fMRI) BOLD signal is commonly localized by using neuroanatomical atlases, which can also serve for region of interest analyses. Yet, the available MRI atlases have serious limitations when it comes to imaging subcortical structures: only 7% of the 455 subcortical nuclei are captured by current atlases. This highlights the general difficulty in mapping smaller nuclei deep in the brain, which can be addressed using ultra-high field 7 Tesla (T) MRI. The ventral tegmental area (VTA) is a subcortical structure that plays a pivotal role in reward processing, learning and memory. Despite the significant interest in this nucleus in cognitive neuroscience, there are currently no available, anatomically precise VTA atlases derived from 7 T MRI data that cover the full region of the VTA. Here, we first provide a protocol for multimodal VTA imaging and delineation. We then provide a data description of a probabilistic VTA atlas based on in vivo 7 T MRI data.

scholarly journals Functional evidence for a direct excitatory projection from the lateral habenula to the ventral tegmental area in the rat

2016 ◽  
Vol 116 (3) ◽  
pp. 1161-1174 ◽  
Author(s):  
P. Leon Brown ◽  
Paul D. Shepard
Keyword(s):  
Ventral Tegmental Area ◽  
Dopamine Neurons ◽  
Lateral Habenula ◽  
Aversive Stimuli ◽  
Rat Pups ◽  
Tegmental Nucleus ◽  
Fasciculus Retroflexus ◽  
Ventral Tegmental ◽  
Midbrain Dopamine ◽  
Midbrain Dopamine Neurons

The lateral habenula, a phylogenetically conserved epithalamic structure, is activated by aversive stimuli and reward omission. Excitatory efferents from the lateral habenula predominately inhibit midbrain dopamine neuronal firing through a disynaptic, feedforward inhibitory mechanism involving the rostromedial tegmental nucleus. However, the lateral habenula also directly targets dopamine neurons within the ventral tegmental area, suggesting that opposing actions may result from increased lateral habenula activity. In the present study, we tested the effect of habenular efferent stimulation on dopamine and nondopamine neurons in the ventral tegmental area of Sprague-Dawley rats using a parasagittal brain slice preparation. Single pulse stimulation of the fasciculus retroflexus excited 48% of dopamine neurons and 51% of nondopamine neurons in the ventral tegmental area of rat pups. These proportions were not altered by excision of the rostromedial tegmental nucleus and were evident in both cortical- and striatal-projecting dopamine neurons. Glutamate receptor antagonists blocked this excitation, and fasciculus retroflexus stimulation elicited evoked excitatory postsynaptic potentials with a nearly constant onset latency, indicative of a monosynaptic, glutamatergic connection. Comparison of responses in rat pups and young adults showed no significant difference in the proportion of neurons excited by fasciculus retroflexus stimulation. Our data indicate that the well-known, indirect inhibitory effect of lateral habenula activation on midbrain dopamine neurons is complemented by a significant, direct excitatory effect. This pathway may contribute to the role of midbrain dopamine neurons in processing aversive stimuli and salience.

Response properties and functional organization of neurons in midline region of medullary reticular formation of cats

1984 ◽  
Vol 52 (5) ◽  
pp. 961-979 ◽  
Author(s):  
C. T. Yen ◽  
P. S. Blum
Keyword(s):  
Spinal Cord ◽  
Reticular Formation ◽  
Visual Stimuli ◽  
The Body ◽  
Raphe Nuclei ◽  
Auditory Stimuli ◽  
Conduction Velocities ◽  
Medullary Raphe ◽  
The Mean ◽  
Raphé Nuclei

Extracellular single-unit recordings were made in the anesthetized cat from neurons within the medullary raphe nuclei and nearby reticular formation. The descending axons from some of these neurons were characterized in terms of length, conduction velocity, and location within the white matter of the spinal cord. The sensory properties were characterized following somatic, baroreceptor, visual, and auditory stimuli. The mean conduction velocities of the descending axons from neurons in the medullary raphe nuclei and in the magnocellular tegmental field (26 m/s) were significantly slower than the mean conduction velocities of units in the regions immediately dorsal to them (50 m/s). Action potentials in neurons in the medullary raphe nuclei and in the magnocellular tegmental field were evoked by anti-dromic stimulation from the dorsolateral portion of the spinal cord (30 of 43, 70%), whereas neurons located in more dorsal regions along the midline and in the reticular formation projected into the ventral columns (18 of 25, 72%). Neurons were most easily activated by a tap stimulus to the body surface. This stimulus activated 84% of the neurons tested. The receptive fields were large, often including the four limbs, back, and head. Tap-sensitive neurons were found throughout the regions investigated. Stimulation of hair receptors activated 37% of neurons tested, whereas 19% responded to a high-intensity cutaneous stimulus (pinch), 35% responded to baroreceptor stimuli, 32% responded to visual stimuli, and 33% responded to auditory stimuli. Neurons responsive to pinch were likely to respond to baroreceptor stimuli and unlikely to respond to visual stimuli. Neurons responsive to visual stimuli were likely to respond to auditory stimuli.

Unit activity of bulbar raphe nuclei and reticular formation in cats

1973 ◽  
Vol 6 (1) ◽  
pp. 16-24
Author(s):  
V. S. Arutyunov ◽  
S. P. Narikashvili ◽  
T. G. Tatevosyan
Keyword(s):  
Reticular Formation ◽  
Unit Activity ◽  
Raphe Nuclei ◽  
Raphé Nuclei

scholarly journals Visualization of peptide-immunoreactive processes on serotonin-immunoreactive cells using two-color immunoperoxidase staining.

1984 ◽  
Vol 32 (3) ◽  
pp. 311-314 ◽  
Author(s):  
M B Hancock
Keyword(s):  
Substance P ◽  
Reticular Formation ◽  
Raphe Nuclei ◽  
Immunoperoxidase Staining ◽  
Paraffin Sections ◽  
Autonomic Changes ◽  
Raphé Nuclei ◽  
Serotonin Cells

The sequential application of the peroxidase-antiperoxidase (PAP) technique with nickel-intensified DAB and with DAB alone was used to visualize black peptide-immunoreactive endings on amber serotonin-immunoreactive cells in 1-2-micron paraffin sections of the hamster medulla. Met-enkephalin- and substance P-positive terminals were present on serotonin cells in the raphe nuclei, the ventral reticular formation, and in the nucleus interfascicularis hypoglossi. The presence of enkephalin-immunoreactive endings on medullary serotonin-immunoreactive cells correlates with the analgesia and autonomic changes that result from the application of morphine or met-enkephalin to the medulla.

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