Article Figures & Data
Figures
- Figure 1.
Viral circuit mapping of M1 and S1 corticostriatal projections to dorsal striatal SPNs and FSIs. A, Viral circuit mapping strategy highlighting spaghetti monster injections into M1 and S1 from a top-down view (left) and the corticostriatal projection pattern onto biocytin-filled striatal cells from a sagittal view (right). B, Top-left: Low magnification view of a coronal striatal section containing the M1 sm.FP injection site and corticostriatal projections to the DLS. CC, corpus callosum; DLS, dorsolateral striatum. Top-right: Low magnification view of a coronal striatal section with S1 corticostriatal projections labeled with sm.FPs. Bottom-left: Low magnification view of merged fluorescence from S1 and M1 corticostriatal projections innervating a striatal SPN filled with biocytin (white box). Bottom-right: High magnification inset bottom-left image with corticostriatal innervation by M1 and S1 onto a biocytin-filled SPN. C, Left: Pseudo-colored representative image of a biocytin-filled SPN with spiny dendrites (inset). Right: Pseudo-colored representative image of a biocytin-filled FSI with aspiny dendrites (inset). D, Left: Average number of primary dendrites (note that FSIs have more primary dendrites extending from the soma compared to SPNs). Right: Average cross-sectional diameter of the soma. E, Comparison of mean IFF and mean HHW at steady state permits differentiation of FSIs from SPNs due to their fast-firing rates. F, Left: Average max firing frequency. Right: Average ISI. G, Schematic representation of the recording location of the SPNs and FSIs in our dataset (note that all cells were recorded in the anterior dorsal striatum where M1 and S1 innervation was dense).
- Figure 2.
Morphological and electrophysiological properties of SPNs and FSIs. A, Mean cross-sectional diameter of the dendritic field. B, Mean depth of the dendritic field along the z-axis. C, Mean HWH amplitude. D, Mean IFF. E, Mean resting membrane potential voltage. F, Mean input resistance.
- Figure 3.
3D reconstructions of striatal neurons and confirmation of S1 and M1 synaptic puncta. A, 3D reconstruction of biocytin-filled SPNs and FSIs into a “surface” and “filament” object in Imaris. B, Representative raw fluorescence from biocytin, the presynaptic protein bassoon, M1, and S1. C, Merged image from B demonstrating S1 and M1 presynaptic inputs dually innervating an SPN (top) and FSI (bottom).
- Figure 4.
Differential innervation by S1 and M1 to SPNs and FSIs. A, Magnified view of raw fluorescence (left) from S1 and M1 corticostriatal projections onto a biocytin-filled SPN (top) and FSI (bottom) with their associated 3D reconstructions (right). B, Average percent innervation by M1 and S1. C, Mean distribution of S1 and M1 inputs across the neuron when measuring the distance from the soma along the length of a dendrite. D, Representative image of fluorescence from M1 and S1 masked onto a biocytin-filled SPN (left) and FSI (right) that was later used for input analysis.
- Figure 5.
Distribution properties of S1 and M1 inputs to SPNs and FSIs. A, Z-positions of the first and last appearance of a dendrite, and the soma of reconstructed SPNs (left) and FSIs (right) compared with the Z-positions of their associated S1 and M1 inputs. B, Mean total number of combined S1 and M1 inputs counted within 0.5 µm of the filament-constructed SPN or FSI. C, Mean number of inputs counted from S1 and M1 within 0.5 µm of the filament edge. D, Mean percentage of identified M1 and S1 inputs that colocalized with Vglut1. E, Mean ratio of M1 inputs to S1 inputs counted within 0.5 µm of the filament edge. The ratios were statistically compared to a theoretical value of 1 indicated by a red dashed line. F, Cumulative distribution function (CDF) of the M1/S1 ratios. The red dashed line indicates a value of 1, which infers equal innervation by M1 and S1. Gray line = SPNs, black line = FSIs. G, Comparison of M1/S1 ratio with the ML position of the neuron it was recorded from; gray dots = SPNs (N = 12), black dots = FSIs (n = 6). H, Mean distance of an S1 and M1 input from the soma when measured along the length of the dendrite.
- Figure 6.
S1 and M1 inputs are found mostly on the spines of SPNs and dendrites of FSIs. A, Mean percent of total S1 and M1 inputs distributed between the spines, dendrites, and soma for SPNs and FSIs. Since FSIs are aspiny, inputs were segmented between the dendrites and soma. B, Mean percent of total S1 and M1 inputs distributed between the spines, dendrites, and soma for inputs that were found in the proximal regions (0 < 30 µm) of SPNs and FSIs. C, Mean density of S1 and M1 inputs represented as contacts per 10 µm. For SPNs, inputs to spines and dendrites were grouped together.
- Figure 7.
S1 and M1 input cluster on SPNs but not in FSIs. A, Representative image of fluorescence from M1 (red) and S1 (green) masked onto the dendrites of an SPN (left) and an FSI (right). B, Mean distance between the nearest input from the same cortical region. C, Mean distribution of the shortest distance to the nearest input from the same cortical region. D, Mean distance between inputs from different cortical regions. E, Mean percent of S1 and M1 Inputs that are colocalized with an increasing distance threshold for SPNs (right) and FSIs (left). The mean percent was tested against a theoretical value of 50% indicated by the red dashed line using a one-sample t test. F, Mean distance from the soma when measured along the length of the dendrite for S1 and M1 inputs that colocalized within 5 µm of each other. G, Distribution of colocalized inputs from F.
Tables
ML AP DV SPN, N = 12 1.782 ± 0.047 mm 1.023 ± 0.056 mm −2.237 ± 0.075 mm FSI, n = 6 1.896 ± 0.193 mm 0.920 ± 0.134 mm −2.154 ± 0.079 mm The mediolateral (ML), anteroposterior (AP), and dorsoventral (DV) positions of the recorded neuron within the striatum relative to bregma.
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