Cortical connections to area TE in monkey: hybrid modular and distributed organization.
To investigate the fine anatomical organization of cortical inputs to visual association area TE, 2-3 small injections of retrograde tracers were made in macaque monkeys. Injections were made as a terminal procedure, after optical imaging and electrophysiological recording, and targeted to patches physiologically identified as object-selective. Retrogradely labeled neurons occurred in several unimodal visual areas, the superior temporal sulcus, intraparietal sulcus (IPS), and prefrontal cortex (PFC), consistent with previous studies. Despite the small injection size (<0.5 mm wide), the projection foci in visual areas, but not in IPS or PFC, were spatially widespread (4-6 mm in extent), and predominantly consisted of neurons labeled by only one of the injections. This can be seen as a quasi-modular organization. In addition, within each projection focus, there were scattered neurons projecting to one of the other injections, together with some double-labeled (DL) neurons, in a more distributed pattern. Finally, projection foci included smaller "hotspots," consisting of intermixed neurons, single-labeled by the different injections, and DL neurons. DL neurons are likely the result of axons having extended, spatially separated terminal arbors, as demonstrated by anterograde experiments. These results suggest a complex, hybrid connectivity architecture, with both modular and distributed components.
Borra
Elena
E
Dipartimento di Neuroscienze, Sezione di Fisiologia, Università di Parma, Parma, Italy. elena.borra@nemo.unipr.it
Ichinohe
Noritaka
N
Sato
Takayuki
T
Tanifuji
Manabu
M
Rockland
Kathleen S
KS
D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D001931:Brain Mapping; D004594:Electrophysiology; D005455:Fluorescent Antibody Technique; D008253:Macaca mulatta; D008297:Male; D008856:Microscopy, Fluorescence; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D056325:Neuronal Tract-Tracers; D009474:Neurons / Q000166:cytology / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology; D013702:Temporal Lobe / Q000033:anatomy & histology* / Q000502:physiology; D014793:Visual Cortex / Q000033:anatomy & histology* / Q000502:physiology; D014795:Visual Pathways / Q000033:anatomy & histology* / Q000502:physiology; D056969:Voltage-Sensitive Dye Imaging
D056325:Neuronal Tract-Tracers