scholarly journals Corticostriatal Projections of Macaque Area 44

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Cole Korponay ◽  
Eun Young Choi ◽  
Suzanne N Haber
Keyword(s):  
Injection Site ◽  
Caudate Nucleus ◽  
Anterior Commissure ◽  
Cortical Input ◽  
Motor Circuits ◽  
Corticostriatal Projections ◽  
Prior Investigation ◽  
Cortical Regions ◽  
Anterograde And Retrograde Tracing ◽  
Caudal Area

Abstract Ventrolateral frontal area 44 is implicated in inhibitory motor functions and facilitating prefrontal control over vocalization. The contribution of corticostriatal circuits to area 44 functions is unclear, as prior investigation of area 44 projections to the striatum—a central structure in motor circuits—is limited. Here, we used anterograde and retrograde tracing in macaques to map the innervation zone of area 44 corticostriatal projections, quantify their strengths, and evaluate their convergence with corticostriatal projections from other frontal cortical regions. First, whereas terminal fields from a rostral area 44 injection site were found primarily in the central caudate nucleus, those from a caudal area 44 injection site were found primarily in the ventrolateral putamen. Second, amongst sampled injection sites, area 44 input as a percentage of total frontal cortical input was highest in the ventral putamen at the level of the anterior commissure. Third, area 44 projections converged with orofacial premotor area 6VR and other motor-related projections (in the putamen), and with nonmotor prefrontal projections (in the caudate nucleus). Findings support the role of area 44 as an interface between motor and nonmotor functional domains, possibly facilitated by rostral and caudal area 44 subregions with distinct corticostriatal connectivity profiles.

scholarly journals Corticostriatal Projections of Macaque Area 44

2020 ◽  
Author(s):  
Cole Korponay ◽  
Eun Young Choi ◽  
Suzanne N. Haber
Keyword(s):  
Injection Site ◽  
Caudate Nucleus ◽  
Anterior Commissure ◽  
Retrograde Tracing ◽  
Cortical Input ◽  
Corticostriatal Projections ◽  
Prior Investigation ◽  
Anterograde And Retrograde Tracing ◽  
Caudal Area

ABSTRACTVentrolateral frontal area 44 is implicated in inhibitory motor functions and facilitating prefrontal control over vocalization. Yet, the corticostriatal circuitry that may contribute to area 44 functions is not clear, as prior investigation of area 44 corticostriatal projections is limited. Here, we used anterograde and retrograde tracing in macaques to map the innervation zone of area 44 corticostriatal projections, quantify their strengths, and evaluate their convergence with corticostriatal projections from non-motor and motor-related frontal regions. First, terminal fields from a rostral area 44 injection site were found primarily in the central caudate nucleus, whereas those from a caudal area 44 injection site were found primarily in the ventrolateral putamen. Second, amongst sampled striatal retrograde injection sites, area 44 input as a percentage of total frontal cortical input was highest in the ventral putamen at the level of the anterior commissure. Third, area 44 projections converged with both orofacial premotor area 6VR and other motor related projections (in the putamen), and with non-motor prefrontal projections (in the caudate nucleus). These findings support the role of area 44 as an interface between motor and non-motor functional domains, possibly facilitated by rostral and caudal area 44 subregions with distinct corticostriatal connectivity profiles.

Hemispheric Coordination Is Necessary for Song Production in Adult Birds: Implications for a Dual Role for Forebrain Nuclei in Vocal Motor Control

2008 ◽  
Vol 99 (1) ◽  
pp. 373-385 ◽  
Author(s):  
Robin C. Ashmore ◽  
Mark Bourjaily ◽  
Marc F. Schmidt
Keyword(s):  
Anterior Commissure ◽  
Temporal Structure ◽  
Dual Role ◽  
Critical Feature ◽  
Motor Circuits ◽  
Output Structure ◽  
Complex Motor ◽  
Song Production ◽  
Song Control ◽  
Avian Song

Precise coordination across hemispheres is a critical feature of many complex motor circuits. In the avian song system the robust nucleus of the arcopallium (RA) plays a key role in such coordination. It is simultaneously the major output structure for the descending vocal motor pathway, and it also sends inputs to structures in the brain stem and thalamus that project bilaterally back to the forebrain. Because all birds lack a corpus callosum and the anterior commissure does not interconnect any of the song control nuclei directly, these bottom-up connections form the only pathway that can coordinate activity across hemispheres. In this study, we show that unilateral lesions of RA in adult male zebra finches ( Taeniopigia guttata) completely and permanently disrupt the bird's stereotyped song. In contrast, lesions of RA in juvenile birds do not prevent the acquisition of normal song as adults. These results highlight the importance of hemispheric interdependence once the circuit is established but show that one hemisphere is sufficient for complex vocal behavior if this interdependence is prevented during a critical period of development. The ability of birds to sing with a single RA provides the opportunity to test the effect of targeted microlesions in RA without confound of functional compensation from the contralateral RA. We show that microlesions cause significant changes in song temporal structure and implicate RA as playing a major part in the generation of song temporal patterns. These findings implicate a dual role for RA, first as part of the program generator for song and second as part of the circuit that mediates interhemispheric coordination.

scholarly journals Distinct roles for motor cortical and thalamic inputs to striatum during motor learning and execution

2019 ◽  
Author(s):  
Steffen B. E. Wolff ◽  
Raymond Ko ◽  
Bence P. Ölveczky
Keyword(s):  
Motor Cortex ◽  
Motor Learning ◽  
Learning Process ◽  
Brain Areas ◽  
Thalamic Neurons ◽  
Cortical Input ◽  
Motor Circuits ◽  
Motor Network ◽  
Motor Cortical ◽  
Cortical Inputs

AbstractThe acquisition and execution of learned motor sequences are mediated by a distributed motor network, spanning cortical and subcortical brain areas. The sensorimotor striatum is an important cog in this network, yet how its two main inputs, from motor cortex and thalamus respectively, contribute to its role in motor learning and execution remains largely unknown. To address this, we trained rats in a task that produces highly stereotyped and idiosyncratic motor sequences. We found that motor cortical input to the sensorimotor striatum is critical for the learning process, but after the behaviors were consolidated, this corticostriatal pathway became dispensable. Functional silencing of striatal-projecting thalamic neurons, however, disrupted the execution of the learned motor sequences, causing rats to revert to behaviors produced early in learning and preventing them from re-learning the task. These results show that the sensorimotor striatum is a conduit through which motor cortical inputs can drive experience-dependent changes in subcortical motor circuits, likely at thalamostriatal synapses.

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.

Albumin outflow into deep cervical lymph from different regions of rabbit brain

1991 ◽  
Vol 261 (4) ◽  
pp. H1197-H1204 ◽  
Author(s):  
S. Yamada ◽  
M. DePasquale ◽  
C. S. Patlak ◽  
H. F. Cserr
Keyword(s):  
Cerebrospinal Fluid ◽  
Injection Site ◽  
Caudate Nucleus ◽  
Internal Capsule ◽  
Rabbit Brain ◽  
Perivascular Spaces ◽  
High Concentration ◽  
Tracer Injection ◽  
Maximum Value ◽  
Collection Period

Dynamics and pathways of 125I-labeled albumin (RISA) outflow from brain to deep cervical lymph have been studied in anesthetized rabbits between 4 and 25 h after microinjection of 1 microliter RISA into the internal capsule or midbrain. Lymph from the jugular lymph trunks was collected for periods of 2-11 h. RISA was cleared from brain with half-times of disappearance from internal capsule and midbrain of 18.2 and 11.9 h, respectively. RISA was distributed in high concentration to subarachnoid arteries that supplied the tissue injection site; this was consistent with RISA drainage from brain via perivascular spaces. Outflow through lymph rose to a maximum value 15-20 h after tracer injection. Mean recovery of RISA from lymph over the 25-h collection period accounted for 22% of total loss from internal capsule and 18% from midbrain. This result compares with mean recoveries from caudate nucleus and cerebrospinal fluid of 47% and 30%, respectively [M.W.B. Bradbury, H.F. Cserr, and R.J. Westrop, Am. J. Physiol. 240 (Renal Fluid Electrolyte Physiol. 9): F329-F336, 1981]. These are minimal estimates of total outflow to lymph because of the 15- to 20-h delay in RISA passage from brain to lymph.

scholarly journals Four-dimensional tractography animates neural propagations via distinct interhemispheric pathways

2020 ◽  
Author(s):  
Takumi Mitsuhashi ◽  
Masaki Sonoda ◽  
Jeong-won Jeong ◽  
Brian H. Silverstein ◽  
Hirotaka Iwaki ◽  
...  
Keyword(s):  
Time Window ◽  
Physiological Function ◽  
Focal Epilepsy ◽  
Anterior Commissure ◽  
Single Pulse ◽  
Peak Latency ◽  
Drug Resistant ◽  
Methodological Study ◽  
Cortical Regions ◽  
Spectral Responses

Objective: To visualize and validate the dynamics of interhemispheric neural propagations induced by single-pulse electrical stimulation (SPES). Methods: This methodological study included three patients with drug-resistant focal epilepsy who underwent measurement of cortico-cortical spectral responses (CCSRs) during bilateral stereo-electroencephalography recording. We delivered SPES to 83 electrode pairs and analyzed CCSRs recorded at 268 nonepileptic electrode sites. Diffusion-weighted imaging (DWI) tractography localized the interhemispheric white matter pathways as streamlines directly connecting two electrode sites. We localized and visualized the putative SPES-related fiber activation, at each 1-ms time window, based on the propagation velocity defined as the DWI-based streamline length divided by the early CCSR peak latency. Results: The resulting movie, herein referred to as four-dimensional tractography, delineated the spatiotemporal dynamics of fiber activation via the corpus callosum and anterior commissure. Longer streamline length was associated with delayed peak latency and smaller amplitude of CCSRs. The cortical regions adjacent to each fiber activation site indeed exhibited CCSRs at the same time window. Conclusions: Our four-dimensional tractography successfully animated neural propagations via distinct interhemispheric pathways. Significance: Our novel animation method has the potential to help investigators in addressing the mechanistic significance of the interhemispheric network dynamics supporting physiological function.

Cortical regions contributing to the anterior commissure in man

1999 ◽  
Vol 124 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Gabrielle Di Virgilio ◽  
S. Clarke ◽  
Gianpaolo Pizzolato ◽  
Thomas Schaffner
Keyword(s):  
Anterior Commissure ◽  
Cortical Regions

scholarly journals Corticostriatal circuitry

2016 ◽  
Vol 18 (1) ◽  
pp. 7-21 ◽  
Keyword(s):  
Motor Control ◽  
Caudate Nucleus ◽  
Ventral Striatum ◽  
Functional Domains ◽  
Motor Functions ◽  
Specific Outcome ◽  
Cortical Regions

Corticostriatal connections play a central role in developing appropriate goal-directed behaviors, including the motivation and cognition to develop appropriate actions to obtain a specific outcome. The cortex projects to the striatum topographically. Thus, different regions of the striatum have been associated with these different functions: the ventral striatum with reward; the caudate nucleus with cognition; and the putamen with motor control. However, corticostriatal connections are more complex, and interactions between functional territories are extensive. These interactions occur in specific regions in which convergence of terminal fields from different functional cortical regions are found. This article provides an overview of the connections of the cortex to the striatum and their role in integrating information across reward, cognitive, and motor functions. Emphasis is placed on the interface between functional domains within the striatum.

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