scholarly journals Multiple non-auditory cortical regions innervate the auditory midbrain

2019 ◽  
Author(s):  
Bas MJ Olthof ◽  
Adrian Rees ◽  
Sarah E Gartside
Keyword(s):  
Inferior Colliculus ◽  
Auditory Perception ◽  
Retrograde Tracing ◽  
Subcortical Structures ◽  
Auditory Midbrain ◽  
Cognitive Domains ◽  
Cortical Areas ◽  
Cortical Regions ◽  
Descending Projections ◽  
Prefrontal Cortices

ABSTRACTOur perceptual experience of sound depends on the integration of multiple sensory and cognitive domains, but the networks sub-serving this integration are unclear. There are connections linking different cortical domains, however we do not know if there are also connections between multiple cortical domains and subcortical structures. Retrograde tracing in rats revealed that the inferior colliculus – the auditory midbrain - receives dense descending projections from not only the auditory cortex, but also the visual, somatosensory, motor, and prefrontal cortices. While all these descending connections are bilateral, those from sensory areas show a more pronounced ipsilateral dominance than those from motor and prefrontal cortices. Anterograde tracing from cortical areas identified by retrograde tracing, showed cortical fibres terminating in all three subdivisions of the inferior colliculus, targeting both inhibitory and excitatory neurons. These findings demonstrate that auditory perception is served by a network that includes extensive descending connections from sensory, behavioural, and executive cortices.

scholarly journals Influence of Nitrous Oxide on Local Cerebral Blood Flow in Awake, Minimally Restrained Rats

1981 ◽  
Vol 1 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Nils Dahlgren ◽  
Martin Ingvar ◽  
Hideo Yokoyama ◽  
Bo K. Siesjö
Keyword(s):  
Blood Flow ◽  
Nitrous Oxide ◽  
Cerebral Blood Flow ◽  
Inferior Colliculus ◽  
Subcortical Structures ◽  
Local Cerebral Blood Flow ◽  
Superior Olive ◽  
Cortical Areas ◽  
Colliculus Superior ◽  
Septal Nuclei

In order to evaluate the effect of 70–80% N2O on local cerebral blood flow (l-CBF) in the rat brain, we developed a procedure for measuring CBF by an autoradiographic [14C]iodoantipyrine technique in awake, minimally restrained animals. Results on l-CBF, as measured in 22 different structures, showed little variability between animals. In the majority of structures analyzed, 70–80% N2O failed to alter l-CBF. These included all cerebral cortical and most subcortical structures. However, nitrous oxide reduced CBF in the the inferior colliculus and the superior olive, in two of the limbic structures analyzed, and in the hypothalamus. In no structure, except the striatum ( p < 0.05), was a significant increase in l-CBF obtained in N2O-breathing animals. However, the results suggest that CBF may have been increased in the auditory cortex. Immobilization was found to reduce l-CBF in the cerebellum, inferior colliculus, superior olive, hippocampus, and septal nuclei. The results also suggest that the procedure somewhat increased CBF in frontal and parietal cortex. When the results obtained in awake, air-breathing animals were compared with those obtained in immobilized animals ventilated on N2O, there was no significant increase in any of the structures analyzed, although there were suggested increases in all cortical areas except the visual cortex. However, the data showed that ventilation with 70–80% N2O significantly decreased CBF in several structures (inferior colliculus, superior olive, hippocampus, amygdala, septal nuceli, and hypothalamus). In some of these, the effects of 70–80% N2O and of immobilization were obviously additive.

scholarly journals Subcortical circuits mediate communication between primary sensory cortical areas in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Lohse ◽  
Johannes C. Dahmen ◽  
Victoria M. Bajo ◽  
Andrew J. King
Keyword(s):  
Cortical Neurons ◽  
Common Property ◽  
Primary Auditory Cortex ◽  
Facilitatory Effect ◽  
Thalamic Nuclei ◽  
Auditory Midbrain ◽  
Cortical Areas ◽  
Auditory Responses ◽  
Evoked Activity

AbstractIntegration of information across the senses is critical for perception and is a common property of neurons in the cerebral cortex, where it is thought to arise primarily from corticocortical connections. Much less is known about the role of subcortical circuits in shaping the multisensory properties of cortical neurons. We show that stimulation of the whiskers causes widespread suppression of sound-evoked activity in mouse primary auditory cortex (A1). This suppression depends on the primary somatosensory cortex (S1), and is implemented through a descending circuit that links S1, via the auditory midbrain, with thalamic neurons that project to A1. Furthermore, a direct pathway from S1 has a facilitatory effect on auditory responses in higher-order thalamic nuclei that project to other brain areas. Crossmodal corticofugal projections to the auditory midbrain and thalamus therefore play a pivotal role in integrating multisensory signals and in enabling communication between different sensory cortical areas.

Subcortical structures projecting to visual cortical areas in squirrel monkey

1982 ◽  
Vol 209 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Johannes Tigges ◽  
M. Tigges ◽  
N. A. Cross ◽  
R. L. McBride ◽  
W. D. Letbetter ◽  
...  
Keyword(s):  
Squirrel Monkey ◽  
Subcortical Structures ◽  
Cortical Areas ◽  
Visual Cortical

Abstract W MP14: Detection of Early Ischemia Varies Extensively with Topography: Concurrent CT versus DWI ASPECTS

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
David S Liebeskind ◽  
Sunil A Sheth ◽  
Farhad Mehrkhani ◽  
Shahmir Kamalian ◽  
Fabien Scalzo ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Symptom Onset ◽  
Regional Variation ◽  
Internal Capsule ◽  
Kappa Statistic ◽  
Subcortical Structures ◽  
Subcortical Regions ◽  
Cortical Regions ◽  
Ct And Mri ◽  
Good Agreement

Background: Numerous studies have compared CT with DWI ASPECTS, yet differences in timing between study acquisition may impart error or confound. We analyzed a large cohort of concurrently acquired CT and MRI to discern differences in regional variation in the ability to detect early ischemia. Methods: CT and DWI were acquired within 1 hour of each other during the first 8 hours after symptom onset and pooled from two large academic stroke centers for these analyses. Two raters independently scored CT ASPECTS and DWI ASPECTS at separate reading sessions. Modified DWI-ASPECTS (including only >20% per region) was also scored. Consensus readings were then utilized to compare regional ASPECTS across the 3 ASPECTS scales using the kappa statistic. Results: 136 patients underwent both CT and DWI within 1 hour of each other in the setting of acute ischemic stroke. Regional involvement on DWI included caudate in 57%, lentiform in 73%, insula in 69%, internal capsule in 24%, M1 in 34%, M2 in 49%, M3 in 36%, M4 in 21%, M5 in 57% and M6 in 41%. The agreement between CT and DWI varied by region, from caudate kappa 0.616 (0.484-0.748), to lentiform 0.602 (0.457-0.748), insula 0.690 (0.558-0.822), internal capsule 0.374 (0.189-0.559), M1 0.583 (0.435-0.731), M2 0.515 (0.389-0.641), M3 0.421 (0.275-0.568), M4 0.453 (0.262-0.644), M5 0.388 (0.268-0.507) and M6 0.500 (0.366-0.634). Modified DWI-ASPECTS (>20% per region) and CT demonstrated overall better agreement, yet still markedly varied by region. In general, CT and DWI ASPECTS reveal good agreement in subcortical structures, whereas very limited agreement is noted in several cortical ischemic regions. Modified-DWI ASPECTS improves cortical agreement, yet remains poor in the internal capsule. Conclusions: Detection of early ischemia varies considerably depending on the location or topography depicted with either CT or MRI. Deep subcortical regions are best detected with either modality, whereas cortical regions exhibit marked distinctions. Modified DWI ASPECTS improves agreement with CT ASPECTS in cortical regions.

scholarly journals Multiple Nonauditory Cortical Regions Innervate the Auditory Midbrain

2019 ◽  
Vol 39 (45) ◽  
pp. 8916-8928 ◽  
Author(s):  
Bas M.J. Olthof ◽  
Adrian Rees ◽  
Sarah E. Gartside
Keyword(s):  
Auditory Midbrain ◽  
Cortical Regions

Opioidergic System and Functional Architecture of Intrinsic Brain Activity: Implications for Psychiatric Disorders

2020 ◽  
Vol 26 (4) ◽  
pp. 343-358
Author(s):  
Giulio Rocchi ◽  
Bruno Sterlini ◽  
Samuele Tardito ◽  
Matilde Inglese ◽  
Anna Corradi ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Opioid Receptors ◽  
Large Scale ◽  
Brain Activity ◽  
Subcortical Structures ◽  
Opioidergic System ◽  
Sensorimotor Network ◽  
Cortical Areas ◽  
High Doses ◽  
Intrinsic Brain Activity

The opioidergic system and intrinsic brain activity, as organized in large-scale networks such as the salience network (SN), sensorimotor network (SMN), and default-mode network (DMN), play core roles in healthy behavior and psychiatric disorders. This work aimed to investigate how opioidergic signaling affects intrinsic brain activity in healthy individuals by reviewing relevant neuroanatomical, molecular, functional, and pharmacological magnetic resonance imaging studies in order to clarify their physiological links and changes in psychiatric disorders. The SN shows dense opioidergic innervations of subcortical structures and high expression levels of opioid receptors in subcortical-cortical areas, with enhanced or reduced activity with low or very high doses of opioids, respectively. The SMN shows high levels of opioid receptors in subcortical areas and functional disconnection caused by opioids. The DMN shows low levels of opioid receptors in cortical areas and inhibited or enhanced activity with low or high doses of opioids, respectively. Finally, we proposed a working model. Opioidergic signaling enhances SN and suppresses SMN (and DMN) activity, resulting in affective excitation with psychomotor inhibition; stronger increases in opioidergic signaling attenuate the SN and SMN while disinhibiting the DMN, dissociating affective and psychomotor functions from the internal states; the opposite occurs with a deficit of opioidergic signaling.

scholarly journals Effects of Electrical Stimulation in the Inferior Colliculus on Frequency Discrimination by Rhesus Monkeys and Implications for the Auditory Midbrain Implant

2016 ◽  
Vol 36 (18) ◽  
pp. 5071-5083 ◽  
Author(s):  
Daniel S. Pages ◽  
Deborah A. Ross ◽  
Vanessa M. Puñal ◽  
Shruti Agashe ◽  
Isaac Dweck ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Inferior Colliculus ◽  
Rhesus Monkeys ◽  
Frequency Discrimination ◽  
Auditory Midbrain

Differential Changes in Functional Connectivity of Striatum-Prefrontal and Striatum-Motor Circuits in Premanifest Huntington’s Disease

2019 ◽  
Vol 19 (2) ◽  
pp. 78-87 ◽  
Author(s):  
Martin Kronenbuerger ◽  
Jun Hua ◽  
Jee Y.A. Bang ◽  
Kia E. Ultz ◽  
Xinyuan Miao ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Cag Repeat ◽  
Compensatory Mechanism ◽  
Motor Score ◽  
Cortical Areas ◽  
Motor Circuits ◽  
Neurophysiological Studies ◽  
Cortical Regions

Background: Huntington’s disease (HD) is a progressive neurodegenerative disorder. The striatum is one of the first brain regions that show detectable atrophy in HD. Previous studies using functional magnetic resonance imaging (fMRI) at 3 tesla (3 T) revealed reduced functional connectivity between striatum and motor cortex in the prodromal period of HD. Neuroanatomical and neurophysiological studies have suggested segregated corticostriatal pathways with distinct loops involving different cortical regions, which may be investigated using fMRI at an ultra-high field (7 T) with enhanced sensitivity compared to lower fields. Objectives: We performed fMRI at 7 T to assess functional connectivity between the striatum and several chosen cortical areas including the motor and prefrontal cortex, in order to better understand brain changes in the striatum-cortical pathways. Method: 13 manifest subjects (age 51 ± 13 years, cytosine-adenine-guanine [CAG] repeat 45 ± 5, Unified Huntington’s Disease Rating Scale [UHDRS] motor score 32 ± 17), 8 subjects in the close-to-onset premanifest period (age 38 ± 10 years, CAG repeat 44 ± 2, UHDRS motor score 8 ± 2), 11 subjects in the far-from-onset premanifest period (age 38 ± 11 years, CAG repeat 42 ± 2, UHDRS motor score 1 ± 2), and 16 healthy controls (age 44 ± 15 years) were studied. The functional connectivity between the striatum and several cortical areas was measured by resting state fMRI at 7 T and analyzed in all participants. Results: Compared to controls, functional connectivity between striatum and premotor area, supplementary motor area, inferior frontal as well as middle frontal regions was altered in HD (all p values <0.001). Specifically, decreased striatum-motor connectivity but increased striatum-prefrontal connectivity were found in premanifest HD subjects. Altered functional connectivity correlated consistently with genetic burden, but not with clinical scores. Conclusions: Differential changes in functional connectivity of striatum-prefrontal and striatum-motor circuits can be found in early and premanifest HD. This may imply a compensatory mechanism, where additional cortical regions are recruited to subserve functions that have been impaired due to HD pathology. Our results suggest the potential value of functional connectivity as a marker for future clinical trials in HD.

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