Barrelettes without Barrels in the American Water Shrew

Catania, Kenneth C.; Catania, Elizabeth H.; Sawyer, Eva K.; Leitch, Duncan B.

doi:10.1371/journal.pone.0065975

Cited by 14 publications

(9 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This overall topography is consistent with the clear map of the nose in primary somatosensory cortex in star‐nosed moles and pigs (Craner and Ray, ; Catania and Kaas, ). This organizational scheme is also consistent with that seen in the brainstem of other species, including pigeons (Silver and Witkovsky, ), cats (Hayashi et al, ), and shrews (Catania et al, ).…”

Section: Discussionsupporting

confidence: 84%

Organization of the spinal trigeminal nucleus in star‐nosed moles

Sawyer

Leitch

Catania

2014

J of Comparative Neurology

Self Cite

View full text Add to dashboard Cite

Somatosensory inputs from the face project to multiple regions of the trigeminal nuclear complex in the brainstem. In mice and rats three subdivisions contain visible representations of the mystacial vibrissae: the principal sensory nucleus, the spinal trigeminal subnucleus interpolaris and subnucleus caudalis. These regions are considered important for touch with high spatial acuity, active touch, and pain and temperature sensation, respectively. Like mice and rats, the star-nosed mole (Condylura cristata) is a somatosensory specialist. Given the visible star pattern in preparations of the star-nosed mole cortex and the principal sensory nucleus, we hypothesized there were star patterns in the spinal trigeminal nucleus subnuclei interpolaris and caudalis. In sections processed for cytochrome oxidase we found star-like segmentation consisting of lightly stained septa separating darkly stained patches in subnucleus interpolaris (juvenile tissue) and subnucleus caudalis (juvenile and adult tissue). Subnucleus caudalis represented the face in a three-dimensional map with the most anterior part of the face represented more rostrally than posterior parts of the face. Multi-unit electrophysiological mapping was used to map the ipsilateral face. Ray-specific receptive fields in adults matched the CO-segmentation. The mean areas of multiunit receptive fields in subnucleus interpolaris and caudalis were larger than previously mapped receptive fields in the mole's principal sensory nucleus. The proportion of tissue devoted to each ray's representation differed between subnucleus interpolaris and the principal sensory nucleus. Our finding that different trigeminal brainstem maps can exaggerate different parts of the face could provide new insights for the roles of these different somatosensory stations.

show abstract

Section: Discussionsupporting

confidence: 84%

Organization of the spinal trigeminal nucleus in star‐nosed moles

Sawyer

Leitch

Catania

2014

J of Comparative Neurology

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, visualization of barreloids can require sectioning of the thalamus at angles that are oblique to standard cutting planes (Haidarliu and Ahissar, ). Furthermore, segmentation in both cortical and subcortical structures may be more clearly identified in juvenile brain tissue compared with adult brain tissue (Haidarliu and Ahissar, ; Catania et al, ). Therefore, to acquire a better understanding of parcellation of the whisker‐to‐cortex pathway in short‐tailed opossums, a more thorough examination of cortical and subcortical structures must be conducted over the course of development.…”

Section: Discussionmentioning

confidence: 99%

“…Short‐tailed opossums, on the other hand, lack any histologically detectable barrels or septa in S1 (Huffman et al, ; Wong and Kaas, ). This is not an anomaly; many animals that possess whiskers do not have detectable barrels in the cortex (Woolsey et al, ), although barrel‐like structures may be present at subcortical levels, for example, in cats and other carnivores (Nomura et al, ) and in water shrews (Catania et al, ).…”

mentioning

confidence: 99%

“…Short-tailed opossums, on the other hand, lack any histologically detectable barrels or septa in S1 (Huffman et al, 1999;Wong and Kaas, 2009). This is not an anomaly; many animals that possess whiskers do not have detectable barrels in the cortex , although barrel-like structures may be present at subcortical levels, for example, in cats and other carnivores (Nomura et al, 1986) and in water shrews (Catania et al, 2013). The functional organization of barrel cortex in rats and mice has been described in great detail; there is a precise spatiotopic map of the whisker array in layer IV of S1, such that neurons in each barrel respond primarily to a single best whisker (BW; Welker, 1971Welker, , 1976Simons, 1978).…”

mentioning

confidence: 99%

See 1 more Smart Citation

The evolution of whisker‐mediated somatosensation in mammals: Sensory processing in barrelless S1 cortex of a marsupial, Monodelphis domestica

Ramamurthy

Krubitzer

2016

J of Comparative Neurology

View full text Add to dashboard Cite

Movable tactile sensors in the form of whiskers are present in most mammals, but sensory coding in the cortical whisker representation has been studied almost exclusively in mice and rats. Many species that possess whiskers lack the modular “barrel” organization found in the primary somatosensory cortex (S1) of mice and rats, but it is unclear how whisker-related input is represented in these species. We used single-unit extracellular recording techniques to characterize receptive fields and response properties in S1 of Monodelphis domestica (short-tailed opossum), a nocturnal, terrestrial marsupial that shared its last common ancestor with placental mammals over 160 million years ago. Short-tailed opossums lack barrels and septa in S1, but show active whisking behavior similar to mice and rats. Most neurons in short-tailed opossum S1 exhibited multiwhisker receptive fields, including a single best whisker and lower magnitude responses to the deflection of surrounding whiskers. Mean tuning width was similar to that reported in mice and rats. Both symmetrical and asymmetrical receptive fields were present. Neurons tuned to ventral whiskers tended to show broad tuning along the rostrocaudal axis. Thus, despite the absence of barrels, most receptive field properties were similar to those reported in mice and rats. However, unlike those species, S1 neuronal responses to best whisker and surround whisker deflection showed comparable latencies in short-tailed opossums. This dissimilarity suggests that some aspects of barrel cortex function may not generalize to tactile processing across mammalian species, and may be related to differences in the architecture of the whisker-to-cortex pathway.

show abstract

“…In many species, the individual barrels are larger in the SpVi than in the PrV (5,22). In mice, barrelettes in the SpVi have a cross-sectional diameter of approximately 140-170 μm and 75-105 μm in the PrV (2).…”

Section: Discussionmentioning

confidence: 99%

Subcortical barrelette-like and barreloid-like structures in the prosimian galago ( Otolemur garnetti )

Sawyer

Liao

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Galagos are prosimian primates that resemble ancestral primates more than most other extant primates. As in many other mammals, the facial vibrissae of galagos are distributed across the upper and lower jaws and above the eye. In rats and mice, the mystacial macrovibrissae are represented throughout the ascending trigeminal pathways as arrays of cytoarchitecturally distinct modules, with each module having a nearly one-to-one relationship with a specific facial whisker. The macrovibrissal representations are termed barrelettes in the trigeminal somatosensory brainstem, barreloids in the ventroposterior medial subnucleus of the thalamus, and barrels in primary somatosensory cortex. Despite the presence of facial whiskers in all nonhuman primates, barrel-like structures have not been reported in primates. By staining for cytochrome oxidase, Nissl, and vesicular glutamate transporter proteins, we show a distinct array of barrelette-like and barreloid-like modules in the principal sensory nucleus, the spinal trigeminal nucleus, and the ventroposterior medial subnucleus of the galago, Otolemur garnetti. Labeled terminals of primary sensory neurons in the brainstem and cell bodies of thalamocortically projecting neurons demonstrate that barrelette-like and barreloid-like modules are located in areas of these somatosensory nuclei that are topographically consistent with their role in facial touch. Serendipitously, the plane of section that best displays the barreloid-like modules reveals a remarkably distinct homunculus-like patterning which, we believe, is one of the clearest somatotopic maps of an entire body surface yet found.vibrissa | barrel cortex | trigeminal | somatosensory maps | primate N early all mammals use facial vibrissae as a sensory organ to transduce distant touch. In some species, but most famously in rats and mice, individual whiskers have been shown to be represented as distinct modules in the ascending lemniscal and paralemniscal somatosensory pathways (1). These modules have been termed barrelettes, barreloids, and barrels in the brainstem, thalamus, and cortex, respectively (2-5). The discovery of the barrel pathway has allowed researchers to visualize how somatosensory inputs are anatomically organized in the brain. The barrel pattern provides clear anatomical landmarks that enable further research on the development, connection, functional organization, and plasticity of the somatosensory system. Many investigators have embraced this system in their research programs (for review, see refs. 6 and 7). Beyond the experimental convenience of the system, the nearly perfect correspondence of one whisker to one barrel invokes questions about the development and evolution of nervous systems in general, such as whether development of the organization of sensory systems is largely controlled by properties intrinsic to the central nervous system or largely dictated by the arrangement of peripheral receptors (8, 9). In addition, do whisker modules have a function, or are they just a spandrel (10, 11) that...

show abstract

Barrelettes without Barrels in the American Water Shrew

Cited by 14 publications

References 42 publications

Organization of the spinal trigeminal nucleus in star‐nosed moles

Organization of the spinal trigeminal nucleus in star‐nosed moles

The evolution of whisker‐mediated somatosensation in mammals: Sensory processing in barrelless S1 cortex of a marsupial, Monodelphis domestica

Subcortical barrelette-like and barreloid-like structures in the prosimian galago ( Otolemur garnetti )

Contact Info

Product

Resources

About