Multimodal cortical sensory pathways revealed by sequential transcranial electrical stimulation in mice

• Published in: Neuroscience research Vol. 87; pp. 49 - 55
• Main Authors: Hishida, Ryuichi, Kudoh, Masaharu, Shibuki, Katsuei
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01-10-2014
• Subjects: Animals; Area 2; Auditory Cortex - physiology; Brain Mapping; Cerebral Cortex - physiology; Cortical map; Flavoprotein fluorescence imaging; Flavoproteins; Functional connectivity; Gyrus Cinguli - physiology; Male; Mice; Mice, Inbred C57BL; Multisensory integration; Neural Pathways - physiology; Optical Imaging; Parietal association cortex; Parietal Lobe - physiology; Somatosensory Cortex - physiology; Transcranial Direct Current Stimulation; Visual Cortex - physiology; aCC; Functional connectivity; TES; Cortical map; HP; mV2; lV2; FP; Flavoprotein fluorescence imaging; A1; A2; Parietal association cortex; V1; PtA; V2; Area 2; MM; RSA; AC; SW; AAF; Multisensory integration; PMBSF; aV2; S1; S2
• ISSN: 0168-0102; 1872-8111
• DOI: 10.1016/j.neures.2014.07.004

•Sequential transcranial electrical stimulations revealed cortical pathways in mice.•Activity originating in three different sensory systems converged on area 2.•Outputs from area 2 were conveyed through parietal association area to frontal area.•Area 2 may have an important role in multimodal sensory integration in mice.
We investigated polysynaptic cortical pathways linking primary to multimodal sensory association areas in mice using transcranial flavoprotein imaging combined with sequential application of transcranial electrical stimulation (TES). Stimulation of primary visual cortex (V1) elicited activity in lateral and medial areas of secondary visual cortices (V2), which were reciprocally connected. Stimulation of V2 areas elicited activity in area 2. Similarly, corticocortical pathways from primary somatosensory cortex (S1) through the corresponding secondary somatosensory areas (S2) to area 2 were observed. Auditory pathways from primary auditory area (A1) through peripheral region (area 22) to area 2 and from anterior auditory field to area 2 were also found. Stimulation in area 2 elicited activity in part of parietal association cortex (PtA), which was reciprocally connected with area 2, and in some areas near the midline including retrosplenial cortex (RSA). A cortical pathway from RSA through anterior cingulate cortex (aCC) to frontal areas was also visualized. These results indicate that area 2, surrounded by visual, somatosensory and auditory cortices, may receive inputs from all three primary sensory areas, and may send outputs through the parietal association cortex to frontal areas, suggesting that area 2 may have an important role in multimodal sensory integration in mice.