Cells In Sensorimotor Cortex Research Articles

Inverted pyramidal neurons in chimpanzee sensorimotor cortex are revealed by immunostaining with monoclonal antibody SMI-32

We used the monoclonal antibody SMI-32 to label pyramidal cells of sensorimotor cortex in two chimpanzees.The majority of the pyramidal cells had typical vertically oriented apical dendrites that extended towards the pial surface. A small population of pyramidal cells varied from this orientation, so that the apical dendrites were 20 or more from radial, and were often inverted, extending away from the pial surface.When numbers of non-inverted and inverted pyramidal cells were compared, less than 1% were found to be inverted.

Postsynaptic potential patterns evoked upon cells in sensorimotor cortex of cat by stimulation at the periphery

Intracellular and extracellular recordings were obtained from neurons in the sensorimotor forepaw cortex of chloralose-anesthetized, domestic cats. Cells responding with either spike or slow potential activity only after stimulation of the contralateral forepaw were classified as s neurons; those responding additionally after stimulation of other extremities were classed as m neurons. The postsynaptic potential changes evoked by single electric shock to the central footpad of each limb were of particular interest. Seven of the eight well-isolated s neurons responded to contralateral forepaw shock with a long duration depolarization; one responded with a short duration EPSP, followed immediately by a Cl −-dependent hyperpolarization. No intracellular membrane potential changes were seen on the s neurons after stimulation of other limbs. The typical response of m neurons to stimulation of any limb was a long-duration EPSP, followed by a long, weak IPSP. The IPSP was most prominent after contralateral forepaw shock, occasionally being indistinct after stimulation of other limbs. Although the inhibition typically follows an EPSP, 5 of 83 neurons responded to contralateral forepaw shock with an initial hyperpolarization. The observations are used to evaluate four possible mechanisms for the production of cortical inhibition. The data are best interpreted as resulting from a direct, thalamocortical inhibitory projection; the data are inconsistent with an intracortical, “recurrent” model.