Convergence of sensory inputs upon projection neurons of somatosensory cortex. 1982

P Zarzecki, and D M Wiggin

Cortico-cortical neurons and pyramidal tract neurons of the cat were tested for convergent inputs from forelimb afferents. Neurons were recorded in cortical areas 1, 2, and 3a. Consideration was given to both suprathreshold and subthreshold inputs evoked by electrical stimulation of forelimb nerves. Individual cortico-cortical neurons and also pyramidal tract neurons were characterized by convergence of multiple somatosensory inputs from different regions of skin, from several muscle groups, and between group I deep afferents and low threshold cutaneous afferents. Certain patterns of afferent input varied with cytoarchitectonic area. There was, however, no difference between area 3a and areas 1-2 in the incidence of cross-modality convergence in the form of input from cutaneous and also deep nerves. Many of the inputs were subthreshold. Arguments are presented that these inputs, though subthreshold, must be considered for a role in cortical information processing. The convergent nature of the sensory inputs is discussed in relation to the proposed specificities of cortical columns. The patterns of afferent inputs reaching cortico-cortical neurons seem to be appropriate for them to have a role in the formation of sensory fields of motor cortex neurons. PT neurons of somatosensory cortex have possible roles as modifiers of ascending sensory systems, however, the convergent input which these PT neurons receive argues against a simple relationship between the modality of peripheral stimuli influencing them and the modality of the ascending tract neurons under their descending control.

UI MeSH Term Description Entries
D008475 Median Nerve A major nerve of the upper extremity. In humans, the fibers of the median nerve originate in the lower cervical and upper thoracic spinal cord (usually C6 to T1), travel via the brachial plexus, and supply sensory and motor innervation to parts of the forearm and hand. Median Nerves,Nerve, Median,Nerves, Median
D009132 Muscles Contractile tissue that produces movement in animals. Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009474 Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM. Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D011712 Pyramidal Tracts Fibers that arise from cells within the cerebral cortex, pass through the medullary pyramid, and descend in the spinal cord. Many authorities say the pyramidal tracts include both the corticospinal and corticobulbar tracts. Corticobulbar Tracts,Corticospinal Tracts,Decussation, Pyramidal,Corticobulbar Tract,Corticospinal Tract,Pyramidal Decussation,Pyramidal Tract,Tract, Corticobulbar,Tract, Corticospinal,Tract, Pyramidal,Tracts, Corticobulbar,Tracts, Corticospinal,Tracts, Pyramidal
D011826 Radial Nerve A major nerve of the upper extremity. In humans the fibers of the radial nerve originate in the lower cervical and upper thoracic spinal cord (usually C5 to T1), travel via the posterior cord of the brachial plexus, and supply motor innervation to extensor muscles of the arm and cutaneous sensory fibers to extensor regions of the arm and hand. Nerve, Radial,Nerves, Radial,Radial Nerves
D001931 Brain Mapping Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures. Brain Electrical Activity Mapping,Functional Cerebral Localization,Topographic Brain Mapping,Brain Mapping, Topographic,Functional Cerebral Localizations,Mapping, Brain,Mapping, Topographic Brain
D002415 Cats The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801) Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004292 Dominance, Cerebral Dominance of one cerebral hemisphere over the other in cerebral functions. Cerebral Dominance,Hemispheric Specialization,Dominances, Cerebral,Specialization, Hemispheric
D004558 Electric Stimulation Use of electric potential or currents to elicit biological responses. Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D005073 Evoked Potentials, Somatosensory The electric response evoked in the CEREBRAL CORTEX by stimulation along AFFERENT PATHWAYS from PERIPHERAL NERVES to CEREBRUM. Somatosensory Evoked Potentials,Evoked Potential, Somatosensory,Somatosensory Evoked Potential

Related Publications

P Zarzecki, and D M Wiggin
January 1985, Experimental brain research,
P Zarzecki, and D M Wiggin
January 1978, Acta oto-laryngologica,
P Zarzecki, and D M Wiggin
October 1983, Brain research,
P Zarzecki, and D M Wiggin
February 1979, Fiziologicheskii zhurnal SSSR imeni I. M. Sechenova,
P Zarzecki, and D M Wiggin
June 1990, Brain research bulletin,
P Zarzecki, and D M Wiggin
June 1998, The Journal of neuroscience : the official journal of the Society for Neuroscience,
P Zarzecki, and D M Wiggin
September 2009, Journal of neurophysiology,
Copied contents to your clipboard!