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K C Catania

Publications and source records attributed to K C Catania.

28 records · Page 2Linked to original sources
PubMed1997

The mole nose instructs the brain.

Star-nosed moles normally have 11 mobile appendages, or rays, extending from each side of the nose. In cytochrome oxidase preparations, each ray is visible in primary somatosensory cortex as a dark band separated by light septa. When a single mole was found with 12 rays on each side of the nose, primary somatosensory cortex had 12 bands. We take this as further evidence that morphological features of somatosensory cortex are determined by the periphery.

Afferent Pathways↗
PubMed1996

Ultrastructure of the Eimer's organ of the star-nosed mole.

The nose of the star-nosed mole consists of 22 fleshy appendages that fan out from around the nostrils and are covered with specialized epidermal sensory receptors called Eimer's organs. The Eimer's organs of the star-nosed mole are domed epidermal papillae approximately 40 to 50 microns in diameter. The center of each papilla contains a column of stacked circular epidermal cells closely associated with five to ten neural processes that originate from three myelinated fibers in the underlying dermis. At middle and lower levels in the cell column, a single nerve fiber is located in the center of the column, enclosed by the epidermal cells which wrap around the fiber and form desmosomes between their own adjacent plasma membranes. An additional five to ten fibers travel up the sides of the column ensheathed in the margins of the epidermal cells. At the top of the cell column, the nerve fibers produce a repeated series of terminal swellings. These terminal swellings converge in the center of the column, where a single epidermal cell completely encapsulates each circular arrangement of nerve terminals. No synapses or other cellular junctions were observed between the nerve terminals where they converge within the cell column. There is a single Merkel-like ending at the base of the cell column, and a single encapsulated corpuscle beneath the cell column, in the connective tissue of the dermis. The structure of Eimer's organs is consistent with a mechanoreceptive function.

Animals↗
PubMed1995

A comparison of the Eimer's organs of three North American moles: the hairy-tailed mole (Parascalops breweri), the star-nosed mole (Condylura cristata), and the eastern mole (Scalopus aquaticus).

Eimer's organ is a tactile sensory structure found predominantly on the snouts of moles. It consists of a raised papilla of epidermis containing a column of cells associated with sensory receptors. This study compares the Eimer's organs of the hairy-tailed mole, Parascalops breweri, the star-nosed mole, Condylura cristata, and the eastern mole, Scalopus aquaticus, by using scanning electron microscopy and light microscopy. Eimer's organs are visible on the snout of the hairy-tailed and the star-nosed moles, but not the eastern mole. The Eimer's organs of the hairy-tailed mole are similar in external appearance, distribution, and internal structure to those found in most species examined. The Eimer's organs of the star-nosed mole and the eastern mole diverge from this basic form in seemingly opposite directions. The Eimer's organs of the star-nosed mole are more numerous, smaller, and highly organized units with a consistent pattern of neuronal terminal swellings within a cell column, below a thin keratinized epidermis. By contrast, the Eimer's organs of the eastern mole lie below a thick keratinized epidermis, are less organized in structure, and have no central cell column. The extreme differences between the Eimer's organs of the star-nosed mole and thos of the eastern mole may be the result of the habitat of each species, saturated mud allowing a more elaborate and delicate sensory apparatus in the star-nosed mole and drier soil requiring a thick keratinized epidermis over the organ in the eastern mole.

Animals↗
PubMed1995

Structure and innervation of the sensory organs on the snout of the star-nosed mole.

The star-nosed mole possesses a conspicuous specialization of its snout in the form of 22 fleshy appendages that fan out from around the nostrils. These appendages are used by the mole to explore its underground environment and are repeatedly brought into contact with objects of interest to the mole. This report describes the structure, innervation, and distribution of the sensory organs on the star of the star-nosed mole and briefly describes the behavioral use of the star. Each of the 22 appendages of the star is covered with a continuous array of Eimer's organs. These sensory receptors are modifications of the epidermal surface that take the form of bulbous papillae. Each Eimer's organ contains a column or stack of epidermal cells accompanied by nerve processes that originate from myelinated fibers in the underlying dermis. These neural processes travel through the cell column and form terminal swellings just below the outer layer of keratinized epidermis. Each Eimer's organ also contains a single Merkel cell-neurite complex within the cell column and a single lamellated corpuscle immediately below the cell column in the connective tissue of the dermis. There are approximately 30,000 Eimer's organs on the snout of this mammal, making this structure perhaps the most sensitive tactile organ yet discovered for its size. The segregation of these organs to individual appendages, not unlike the fingers of primates, affords an intriguing model for the study of somatosensory systems in mammals.

Animals↗
PubMed1995

Organization of the somatosensory cortex of the star-nosed mole.

The nose of the star-nosed mole consists of a star-like array of 22 fleshy appendages that radiate from the nostrils and are moved about to explore the environment. The surface of each appendage, or ray, is densely packed with bulbous receptor organs (Eimer's organs) that are highly responsive to tactile stimulation. Here, we report that these rays have corresponding morphological specializations in somatosensory cortex. Using a stain for the metabolic enzyme, cytochrome oxidase (CO), to reveal subdivisions of cortex, we disclosed a complex pattern of CO-dense stripes or bands separated by sharp lines or septa of low CO staining. Multiunit microelectrode recordings of neural activity evoked by light tactile stimuli in somatosensory cortex of anesthetized moles allowed us to mark some of the bands and other CO-dark regions with small electrolytic lesions and later relate recording results to the CO pattern. The results suggest that the primary somatosensory cortex, S1, has an unusual ventrolateral location and orientation with representations of mouth, nose rays, facial vibrissae, forepaw, and trunk in a rostrocaudal sequence. Within this presumptive S1, the 11 rays of the contralateral nose are represented as a rostral-to-caudal cortical pinwheel of 11 stripes. Cortex ventral to the primary set of stripes contains a second rostrocaudal representation of the rays as a mirror image of the first. This second set of stripes may be part of the second somatosensory area, S2. A third pattern of CO stripes appears to merge partially with caudal stripes of the first two patterns, so that a full pattern of 11 stripes is not obvious. This representation may correspond to the ventral somatosensory area, VS, of other mammals. An extensive area of cortex separated from the nose by a large septum was responsive to stimulation of the forelimb. Auditory cortex is unusually caudal in this mole, and the presumptive primary visual area is relatively small. These specializations of somatosensory cortex in star-nosed moles may be more patent examples of the consequences of more general factors in brain development. The observations are consistent with the general rule that the terminations of sensory projections with discorrelated activity segregate.

Animals↗
PubMed1994

Development of lateral line organs in the axolotl.

Lateral line sensory receptors and their cranial nerves in axolotls arise from a dorsolateral series of placodes, including the octaval placode, that gives rise to the inner ear and the octaval nerve. Anterodorsal and anteroventral placodes occur rostral to the octaval placode and give rise to anterodorsal and anteroventral lateral line nerves and electroreceptors and mechanoreceptors of the snout, cheek, and lower jaw. Middle, supratemporal, and posterior placodes occur caudal to the octaval placode and give rise to similarly named lateral line nerves, electroreceptors and mechanoreceptors of the occipital region of the head, and trunk neuromasts. All placodes, except the posterior placode, elongate, forming sensory ridges, following the genesis of sensory ganglia. Primary mechanoreceptor primordia begin to form within the central zone of the sensory ridges at stage 36; primary electroreceptor primordia originate within the lateral zones of these ridges at stage 38. The first primary mechanoreceptors erupt during stage 37; all primary mechanoreceptors have erupted at hatching (stage 41). Primary electroreceptors begin to erupt at stage 43. Secondary mechanoreceptor primordia begin to form in 1-week-old larvae and erupt 1-2 weeks later. Secondary electroreceptor primordia also begin to form in 1-week-old larvae and continue until clusters of two to five electroreceptors are formed. The developmental stages thought to characterize lateral line placodes in the earliest gnathostomes suggest that this ancestral ontogeny has been truncated in modern amphibians, and ontogenetic mechanisms underlying placodal differentiation are suggested.

Ambystoma mexicanum↗
PubMed1992

Development of partner preferences in female prairie voles (Microtus ochrogaster): the role of social and sexual experience.

Prairie voles (Microtus ochrogaster) exhibit a monogamous mating system characterized by long-term pair bonds between mates. The purpose of this study was to examine the effect of cohabitation time and sexual experience on the development of pair bond formation in female prairie voles. Females that were allowed to cohabit for 24 hr or more, with or without mating, exhibited a strong social preference for a familiar partner versus a strange male. Females that cohabited and mated for 6 hr showed strong preferences for a familiar partner, while cohabitation for less than 24 hr, without mating, did not result in preferences for the familiar male. These results indicate that mating was not essential for partner preference formation; however, preferences developed more rapidly when mating occurred.

Aggression↗
PubMedDate not supplied

A histologically visible representation of the fingers and palm in primate area 3b and its immutability following long-term deafferentations.

An isomorph of the glabrous hand is visible in primary somato-sensory cortex (area 3b) of owl monkeys in brain sections cut parallel to the surface and stained for myelin. A mediolateral row of five ovals, separated by myelin-light septa, represents digits and corresponds precisely with cortical sites activated by light touch on individual digits in microelectrode recordings. A number of caudal ovals relate to pads of the palm. A more distinct septum separates the hand from the more lateral face representation. Within the face representation, two large myelin-dense ovals can be identified that are activated by the upper or lower face in a caudo-rostral sequence. Accidental finger loss or dorsal column section, deafferentations that result in reorganization of the physiological map in area 3b, do not alter the morphological map. The proportions for each digit and palm in the morphological map do not vary across normal and deafferented animals. Similar isomorphs were also seen in area 3b of squirrel and macaque monkeys. We conclude that the anatomical isomorph for the body surface representation in area 3b is a reliable reflection of normal cortical organization and may be a common feature of the primate area 3b. The isomorph can provide a reference in studies of somatotopic reorganization.

Afferent Pathways↗