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.

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 control of defense behavior in mice induced by auditory looming cues

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhong Li ◽  
Jin-Xing Wei ◽  
Guang-Wei Zhang ◽  
Junxiang J. Huang ◽  
Brian Zingg ◽  
...  
Keyword(s):  
Essential Role ◽  
Neural Circuits ◽  
Temporal Dynamics ◽  
Defense Behavior ◽  
Innate Defense ◽  
Sensory Inputs ◽  
Corticostriatal Projections ◽  
Behavioral Transition ◽  
Auditory Looming

AbstractAnimals exhibit innate defense behaviors in response to approaching threats cued by the dynamics of sensory inputs of various modalities. The underlying neural circuits have been mostly studied in the visual system, but remain unclear for other modalities. Here, by utilizing sounds with increasing (vs. decreasing) loudness to mimic looming (vs. receding) objects, we find that looming sounds elicit stereotypical sequential defensive reactions: freezing followed by flight. Both behaviors require the activity of auditory cortex, in particular the sustained type of responses, but are differentially mediated by corticostriatal projections primarily innervating D2 neurons in the tail of the striatum and corticocollicular projections to the superior colliculus, respectively. The behavioral transition from freezing to flight can be attributed to the differential temporal dynamics of the striatal and collicular neurons in their responses to looming sound stimuli. Our results reveal an essential role of the striatum in the innate defense control.

On the role of germ cells in planarian regeneration

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 53-63
Author(s):  
V. Gremigni ◽  
C. Miceli ◽  
I. Puccinelli
Keyword(s):  
Chromosome Number ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Karyological Analysis ◽  
Blastema Formation ◽  
Planarian Regeneration ◽  
Somatic Tissues ◽  
Caudal Area ◽  
Complete Regeneration

Specimens from a polyploid biotype of Dugesia lugubris s.l. were used to clarify the role and fate of germ cells during planarian regeneration. These specimens provide a useful karyological marker because embryonic and somatic cells (3n = 12) can be easily distinguished from male (2n = 8) and female (6n = 24) germ cells by their chromosome number. We succeed in demonstrating how primordial germ cells participate in blastema formation and take part in rebuilding somatic tissues. This evidence was obtained by cutting each planarian specimen twice at appropriate levels. The first aimed to induce primordial germ cells to migrate to the wound. The second cut was performed after complete regeneration and aimed to obtain a blastema from a cephalic or caudal area devoid of gonads. A karyological analysis of mitotic cells present in each blastema obtained after the second cut provided evidence that cells, originally belonging to the germ lines, are still present in somatic tissues even months after complete regeneration. The role of primordial germ cells in planarian regeneration was finally discussed in relation to the phenomenon of metaplasia or transdifferentiation.

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