ISSN:0006-8977    

DOI:10.1159/000123813

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Somatic sensory, auditory and visual areas of cerebral neocortex were mapped in anesthetized capybaras using surface macroelectrode-evoked potential recording methods. The cortical motor area was mapped using electrical stimulation methods. The results of these experiments in the largest living rodent were similar to those found for the cortical sensory and motor areas of guinea pigs, a small rodent in a closely related family. The representation of the perioral skin in SI cortex was relatively large in capybaras and guinea pigs. In capybara, several cortical sulci reliably demarcate different cortical projection areas from one another. Quantitative neuroanatomical comparisons of volumes and neuron numbers in several major prosencephalic nuclei revealed that all nuclear masses are larger in capybara than in guinea pig, but that different nuclei are enlarged to different degrees. Possible causes of larger brains in larger animals are discussed.

ISSN:0006-8977    

DOI:10.1159/000123814

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Microelectrode mapping methods and strategies were developed to map fine details of the somatotopic; organization of somatic sensory cortex (SI) in slow loris. In-depth, multiple-unit recording, and threshold natural stimulation of skin and hair revealed three modality-specific cortical areas. The centrally located one was activated by extremely light touch and the somatotopic organization of peripheral projections to it was mapped in detail. As many as 25 punctures/mm2 were made in delineating these details. The microelectrode mapping method used revealed smaller receptive fields, lesser degrees of overlap, a more differentiated pattern of peripheral projections, and a more precise correlation of electrophysiological results with underlying cytoarchitectonic details than did the usual macroelectrode surface recording method. These results and the correlations found between different physiologically defined areas and cortical sulci are discussed as they pertain to methodological advances in studies of cerebral localization of function.

ISSN:0006-8977    

DOI:10.1159/000123815

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The somatic sensory cortex (SI and SII) was mapped in llamas using microelectrode mapping methods developed earlier in a study of SI of the slow loris. Projections to SI from the llama''s prehensile browsing lips were differentially enlarged when compared to those reported for sheep. In llama, SII was reversed in its mediolateral pattern from that reported for SII in most other mammals. Fissural landmarks reliably demarcated different projections within SI, between SI and SII and between SI or SII and other surrounding nonsensory areas. The use of microelectrode mapping methods in different mammals to determine gyral and fissural homologies is discussed.

ISSN:0006-8977    

DOI:10.1159/000123816

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Somatic sensory (SI) cortex was mapped in hyraxes by micromapping methods developed and used earlier in slow lorises and llamas. The somatotopic pattern of organization was similar in its general features to that found in other mammals. The perioral and intraoral representations are relatively large in SI of hyrax and exhibit considerable distortion. Sulci are reliable landmarks demarcating boundaries of SI in hyrax as they are in other mammals.

ISSN:0006-8977    

DOI:10.1159/000123817

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

In order to gain insight into the functional properties of the tail in North American beavers (Castor canadensis) we (1) examined morphological features of skeletal, muscular, vascular, cutaneous and neural structures; (2) determined the segmental organization of spinal roots and certain stimulus-response features of receptive fields of single dorsal root fibers; (3) mapped the main somatic sensory area (SI) of the cerebral neocortex, and (4) attempted to relate these findings to observations of tail behavior in living beavers. The behavioral observations revealed the beaver capable of forceful yet discrete movements of the tail in water. A morphological correlate of these motor skills was the distinct segmentally organized pattern of serial muscle tendon arrangements and spinal sensory and motor innervation. Neither the receptors innervating the scales or hairs of the tail, the stimulus-response properties of single dorsal root afferents, nor the representation of the tail in SI suggested unusual cutaneous sensory capabilities associated with the morphological and behavioral specializations exhibited by the beaver''s tail.

ISSN:0006-8977    

DOI:10.1159/000123818

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

This essay presents a brief review and evaluation of some guiding concepts during the past century of inquiry into localization of brain functions. Mapping methods are described and discussed as one useful set of approaches to defining functional localization. Each neurobiological discipline: neuroanatomy, neurophysiology, neurochemistry neuropsychology, neuroethology, clinical neurology, biophysics and bioengineering, all use map-making strategies in their search for valid spatial and temporal definitions of the phenomena in their field of interest. Particular emphasis is given to neurophysiological mapping procedures. How these procedures have evolved to become important tools for testing hypotheses about the neuroelectric, behavioral and psychological functions of specific neuroanatomical structures is discussed. The continued importance is emphasized of neurophysiological mapping as a basic set of descriptive sampling strategies for testing hypotheses about specific neural mechanisms and their adaptive operations.

ISSN:0006-8977    

DOI:10.1159/000123819

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000123820

出版商:S. Karger AG    

年代:1976

数据来源: Karger