TY - JOUR
T1 - Receptive field properties of the macaque second somatosensory cortex
T2 - Evidence for multiple functional representations
AU - Fitzgerald, Paul J.
AU - Lane, John W.
AU - Thakur, Pramodsingh H.
AU - Hsiao, Steven S.
PY - 2004/12/8
Y1 - 2004/12/8
N2 - The detailed functional organization of the macaque second somatosensory cortex (SII) is not well understood. Here we report the results of a study of the functional organization of the SII hand region that combines microelectrode mapping using hand-held stimuli with single-unit recordings using a motorized, computer-controlled tactile oriented bar. The data indicate that the SII hand region extends ∼10 mm in the anteroposterior (AP) dimension, primarily within the upper bank of the lateral sulcus. Furthermore, we find evidence that this region consists of multiple functional fields, with a central field containing neurons that are driven well by cutaneous stimuli, flanked by an anterior field and a posterior field that each contain neurons that are driven well by proprioceptive stimuli and less well by cutaneous stimuli. The anterior field extends ∼4-5 mm AP, the central field extends ∼3-4 mm, and the posterior field extends ∼3 mm. Data from the motorized stimulator indicate that neurons in the central field are more responsive to oriented bars, more frequently exhibit orientation tuning, and have larger receptive fields than neurons in the anterior and posterior fields. We speculate that the three putative fields play different functional roles in tactile perception; the anterior and posterior fields process information that involves both proprioceptive and cutaneous input such as sensorimotor integration or stereognosis, whereas the central field processes primarily cutaneous information.
AB - The detailed functional organization of the macaque second somatosensory cortex (SII) is not well understood. Here we report the results of a study of the functional organization of the SII hand region that combines microelectrode mapping using hand-held stimuli with single-unit recordings using a motorized, computer-controlled tactile oriented bar. The data indicate that the SII hand region extends ∼10 mm in the anteroposterior (AP) dimension, primarily within the upper bank of the lateral sulcus. Furthermore, we find evidence that this region consists of multiple functional fields, with a central field containing neurons that are driven well by cutaneous stimuli, flanked by an anterior field and a posterior field that each contain neurons that are driven well by proprioceptive stimuli and less well by cutaneous stimuli. The anterior field extends ∼4-5 mm AP, the central field extends ∼3-4 mm, and the posterior field extends ∼3 mm. Data from the motorized stimulator indicate that neurons in the central field are more responsive to oriented bars, more frequently exhibit orientation tuning, and have larger receptive fields than neurons in the anterior and posterior fields. We speculate that the three putative fields play different functional roles in tactile perception; the anterior and posterior fields process information that involves both proprioceptive and cutaneous input such as sensorimotor integration or stereognosis, whereas the central field processes primarily cutaneous information.
KW - Cortex
KW - Cutaneous
KW - Mapping
KW - Orientation
KW - Proprioceptive (myotactic)
KW - Somatosensory
KW - Tactile
UR - http://www.scopus.com/inward/record.url?scp=10944250435&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=10944250435&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.3481-04.2004
DO - 10.1523/JNEUROSCI.3481-04.2004
M3 - Article
C2 - 15590936
AN - SCOPUS:10944250435
SN - 0270-6474
VL - 24
SP - 11193
EP - 11204
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 49
ER -