Rat whisker motor cortex is subdivided into sensory-input and motor-output areas
Rodent whisking is an exploratory behavior that can be modified by sensory feedback. Consistent with this, many whisker-sensitive cortical regions project to agranular motor (MI) cortex, but the relative topography of these afferent projections has not been established. Intracranial microstimulation...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2013-01-01
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| Series: | Frontiers in Neural Circuits |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fncir.2013.00004/full |
| _version_ | 1819266840865538048 |
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| author | Jared B Smith Kevin D Alloway |
| author_facet | Jared B Smith Kevin D Alloway |
| author_sort | Jared B Smith |
| collection | DOAJ |
| description | Rodent whisking is an exploratory behavior that can be modified by sensory feedback. Consistent with this, many whisker-sensitive cortical regions project to agranular motor (MI) cortex, but the relative topography of these afferent projections has not been established. Intracranial microstimulation (ICMS) evokes whisker movements that are used to map the functional organization of MI, but no study has compared the whisker-related inputs to MI with the ICMS sites that evoke whisker movements. To elucidate this relationship, anterograde tracers were placed in posterior parietal cortex (PPC) and in the primary (SI) and secondary (SII) somatosensory cortical areas so that their labeled projections to MI could be analyzed with respect to ICMS sites that evoke whisker movements. Projections from SI and SII terminate in a narrow zone that marks the transition between the medial (AGm) and lateral agranular (AGl) cortical areas, but PPC projects more medially and terminates in AGm proper. Paired recordings of MI neurons indicate that the region between AGm and AGl is highly responsive to whisker deflections, but neurons in AGm display negligible responses to whisker stimulation. By contrast, AGm microstimulation is more effective in evoking whisker movements than microstimulation of the transitional region between AGm and AGl. The AGm region was also found to contain a larger concentration of corticotectal neurons, which could convey whisker-related information to the facial nucleus. These results indicate that rat whisker motor cortex is comprised of at least two functionally distinct subregions: a sensory processing zone in the transitional region between AGm and AGl, and a motor output region located more medially in AGm proper. |
| first_indexed | 2024-12-23T21:07:40Z |
| format | Article |
| id | doaj.art-329a42ce31be4002a39734d5c643f76a |
| institution | Directory Open Access Journal |
| issn | 1662-5110 |
| language | English |
| last_indexed | 2024-12-23T21:07:40Z |
| publishDate | 2013-01-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Neural Circuits |
| spelling | doaj.art-329a42ce31be4002a39734d5c643f76a2022-12-21T17:31:10ZengFrontiers Media S.A.Frontiers in Neural Circuits1662-51102013-01-01710.3389/fncir.2013.0000440013Rat whisker motor cortex is subdivided into sensory-input and motor-output areasJared B Smith0Kevin D Alloway1Pennsylvania State University College of MedicinePennsylvania State University College of MedicineRodent whisking is an exploratory behavior that can be modified by sensory feedback. Consistent with this, many whisker-sensitive cortical regions project to agranular motor (MI) cortex, but the relative topography of these afferent projections has not been established. Intracranial microstimulation (ICMS) evokes whisker movements that are used to map the functional organization of MI, but no study has compared the whisker-related inputs to MI with the ICMS sites that evoke whisker movements. To elucidate this relationship, anterograde tracers were placed in posterior parietal cortex (PPC) and in the primary (SI) and secondary (SII) somatosensory cortical areas so that their labeled projections to MI could be analyzed with respect to ICMS sites that evoke whisker movements. Projections from SI and SII terminate in a narrow zone that marks the transition between the medial (AGm) and lateral agranular (AGl) cortical areas, but PPC projects more medially and terminates in AGm proper. Paired recordings of MI neurons indicate that the region between AGm and AGl is highly responsive to whisker deflections, but neurons in AGm display negligible responses to whisker stimulation. By contrast, AGm microstimulation is more effective in evoking whisker movements than microstimulation of the transitional region between AGm and AGl. The AGm region was also found to contain a larger concentration of corticotectal neurons, which could convey whisker-related information to the facial nucleus. These results indicate that rat whisker motor cortex is comprised of at least two functionally distinct subregions: a sensory processing zone in the transitional region between AGm and AGl, and a motor output region located more medially in AGm proper.http://journal.frontiersin.org/Journal/10.3389/fncir.2013.00004/fullMotor CortexSomatosensory CortexsensorimotorIntracortical microstimulationneuronal tracing |
| spellingShingle | Jared B Smith Kevin D Alloway Rat whisker motor cortex is subdivided into sensory-input and motor-output areas Frontiers in Neural Circuits Motor Cortex Somatosensory Cortex sensorimotor Intracortical microstimulation neuronal tracing |
| title | Rat whisker motor cortex is subdivided into sensory-input and motor-output areas |
| title_full | Rat whisker motor cortex is subdivided into sensory-input and motor-output areas |
| title_fullStr | Rat whisker motor cortex is subdivided into sensory-input and motor-output areas |
| title_full_unstemmed | Rat whisker motor cortex is subdivided into sensory-input and motor-output areas |
| title_short | Rat whisker motor cortex is subdivided into sensory-input and motor-output areas |
| title_sort | rat whisker motor cortex is subdivided into sensory input and motor output areas |
| topic | Motor Cortex Somatosensory Cortex sensorimotor Intracortical microstimulation neuronal tracing |
| url | http://journal.frontiersin.org/Journal/10.3389/fncir.2013.00004/full |
| work_keys_str_mv | AT jaredbsmith ratwhiskermotorcortexissubdividedintosensoryinputandmotoroutputareas AT kevindalloway ratwhiskermotorcortexissubdividedintosensoryinputandmotoroutputareas |