Skip to main content
. 2016 Dec 5;113(51):E8306–E8315. doi: 10.1073/pnas.1616361113

Fig. 2.

Fig. 2.

Low-frequency (1 Hz), not high-frequency (5–40 Hz), optogenetic excitation of VPM thalamo-cortical excitatory neurons evokes brain-wide positive BOLD activations in remote and bilateral sensory cortices. (A) Illustration of Paxinos atlas-based ROI definitions. S1BF: primary somatosensory barrel field; V1: primary visual cortex; M1: motor cortex; S1ULp: primary somatosensory upper lip area; S2: secondary somatosensory cortex; A1: primary auditory cortex; SC: superior colliculus; LGN: lateral geniculate nucleus; V2: secondary visual cortex; Cg: cingulate cortex. (B) Averaged BOLD activation maps at 1, 5, 10, 20, and 40 Hz of optogenetic stimulation (n = 6; P < 0.001; asterisk: stimulation site). Robust and diffuse positive BOLD activations were observed in bilateral S1BF, V1/V2, A1, S2, and Cg cortices upon 1 Hz of stimulation. When stimulation frequency was increased to 5 and 10 Hz, robust and diffuse positive BOLD activations were observed in ipsilateral S1BF, M1, S1ULp, and S2. Further increase in stimulation frequency to 20 and 40 Hz activated only the ipsilateral S1BF, S1ULp, and S2. (C) BOLD signal profiles extracted from ROIs defined in A (error bar indicates ± SEM).