Journal: bioRxiv

Article Title: Distinct fastigial output channels and their impact on temporal lobe seizures

doi: 10.1101/2021.08.18.456836

Figure Lengend Snippet: Viral labeling illustrates a large number of downstream targets of fastigial neurons. A) Schematic of injection targeting, in which mice are injected with an AAV to induce the expression of GFP in fastigial neurons for broad labeling of fastigial outputs. B-C) GFP expression in fastigial neurons at two different magnifications. D) Six weeks post injection, GFP+ fastigial fibers are visible in the thalamus (D) including central lateral (ii), ventral lateral (iii), parafascicular (iv), medial dorsal (v), ventral medial (vi) and zona incerta (vii) nuclei. Blue box over white schematic indicates approximate region of focus. E) Fastigial fibers are also visible in the superior colliculus, including both deep and intermediate layers (ii-iii). F) In the midbrain, fastigial fibers are observed in the mesencephalic reticular formation (ii), laterodorsal tegmental nucleus (iii), as well as both the lateral (iv) and ventral lateral (v) periaqueductal gray. G) Extensive fastigial fibers are visible in the brainstem, including the medullary reticular formation (ii), vestibular nuclei including the spinal vestibular nucleus (iii), and pontine reticular nuclei (iv, vi). Fibers are also visible in more caudal regions of the brainstem, likely travelling to the spinal cord (v). CL: central lateral nucleus, MDL: medial dorsal nucleus, lateral part, VL: ventral lateral nucleus, VM: ventral medial nucleus, PC: paracentral nucleus, SC: superior colliculus, scp: superior cerebellar peduncle, PaF: parafascicular nucleus, ZI: zona incerta, SC: superior colliculus, SuG: superior gray layer, InG: intermediate gray layer, DpG: deep gray layer, vlPAG: ventral lateral periaqueductal gray, LDTg: laterodorsal tegmental nucleus, mRT: mesencephalic reticular nucleus, lPAG: lateral periaqueductal gray, PnC: nucleus reticularis pontis caudalis, Gi: gigantocellular reticular nucleus, MdV: medullary reticular nucleus (ventral part), SpVe: spinal vestibular nucleus, PCRT: parvocellular reticular nucleus. All images are taken from sagittal sections; see methods for approximate medial lateral coordinates for each region. Scale bars: 200 µm (B); 50µm (C); 500 µm (D, G); 250 µm (E, Eii, F); 50µm (Dii-vii, Eiii, Fii-v, Gii-vi)

Article Snippet: Following retrograde viral injection, the contralateral fastigial nucleus (6.48 posterior, 0.75 left, 3.7 mm ventral from bregma) was injected with virus encoding Channelrhodopsin in a cre-dependent manner (AAV9-EF1a-double floxed-hChR2(H134R)-EYFP-WPRE-HGHpA, titer of 2.2×10 13 Addgene viral prep #202198-AAV9, lot #V22125, provided to Addgene by Karl Deisseroth)( ) consistent with our previously published methods for successful viral targeting of this nucleus ( ).

Techniques: Labeling, Injection, Expressing

Journal: bioRxiv

Article Title: Distinct fastigial output channels and their impact on temporal lobe seizures

doi: 10.1101/2021.08.18.456836

Figure Lengend Snippet: A dual-virus targeting strategy reveals fastigial output channels to segregated projection targets. A) Schematic of injection targeting for FN-SC neurons. Mice are injected with a virus for retrograde expression of Cre (red syringe) in the superior colliculus followed by injection of a virus for Cre-dependent expression of ChR-eYFP in the fastigial nucleus (green syringe). Dual injection results in labeling of fastigial neurons (i) after injection to superior colliculus (ii, arrows denote injection tract). FN-SC cell bodies expressing ChR-eYFP are observed in the caudal fastigial nucleus (iii), and VGluT2+ (shown in red) fastigial fibers (green) are present in the superior colliculus (iv). B) same as for (A), but for MdV injection targeting, in which fastigial cell bodies (i) are labeled after retro-virus injection in the MdV (ii). FN-MdV cell bodies expressing ChR-eYFP are observed in both rostral and caudal portions of the fastigial nucleus (iii), and VGluT2+ fastigial fibers are present in the MdV (iv). C) Same as for (A-B), but for CL retro-virus injection targeting. D-F) Extensive fastigial fibers are observed in the SC for FN-SC, but not FN-MdV nor FN-CL neurons. G) Histogram of path lengths in the SC for FN-SC (magenta), FN-MdV (teal), and FN-CL (yellow) neurons (n = 3 animals per group, inset indicates total path lengths for each individual animal). H-J) Extensive fastigial fibers are observed in the MdV for FN-MdV, but not for FN-SC or FN-CL, neurons. K) Histogram of path lengths and inset dot plots of total path length for each individual animal in the MdV for FN-SC, FN-MdV, and FN-CL neurons. L-N) Dense fibers are observed in the CL for FN-CL, but not SC or MdV, neurons. O) Histogram of path lengths and inset dot plots of total path length for each individual animal in the CL for FN-SC, FN-MdV and FN-CL neurons. All images are taken from sagittal sections. Scale bars: 20µm (Ai, Bi, Ci); 100µm (Aii, Bii, Cii); 200µm (Aiii, Biii, Ciii); 10µm (Aiv, Biv, Civ, insets 2µm) 50µm (D-F, H-J, L-N).

Article Snippet: Following retrograde viral injection, the contralateral fastigial nucleus (6.48 posterior, 0.75 left, 3.7 mm ventral from bregma) was injected with virus encoding Channelrhodopsin in a cre-dependent manner (AAV9-EF1a-double floxed-hChR2(H134R)-EYFP-WPRE-HGHpA, titer of 2.2×10 13 Addgene viral prep #202198-AAV9, lot #V22125, provided to Addgene by Karl Deisseroth)( ) consistent with our previously published methods for successful viral targeting of this nucleus ( ).

Techniques: Virus, Injection, Expressing, Labeling

Journal: bioRxiv

Article Title: Distinct fastigial output channels and their impact on temporal lobe seizures

doi: 10.1101/2021.08.18.456836

Figure Lengend Snippet: Fastigial outputs form largely segregated, but somewhat overlapping, channels. A-F) Histograms of path lengths of fibers in thalamic (A-F), midbrain (G-J), and brainstem nuclei (K-M) for FN-SC (magenta), FN-MdV (teal), and FN-CL (yellow) neurons (n = 3 animals per group, dot plot insets indicate total path length for each animal across all groups). Note differences in y-axis scales for different regions. N-P) Schematic illustrations of brain regions receiving relatively strong inputs from FN-SC (N), FN-MdV (O), and FN-CL (P) neurons, with line thickness roughly indicating relative strength, compared to max-observed fastigial inputs to that area. VN: Vestibular nuclei including SpVe, SuVE, and MVe; note that quantification was only done for SpVe. MedRT: Medullary reticular nuclei including Gi and MdD; note that quantification was only done for MdV. PonRT: Pontine reticular nuclei including PnC, PnO, PCRT, and PCRTa; note that quantification was only done for PnC and PCRT. All other abbreviations are as for - .

Article Snippet: Following retrograde viral injection, the contralateral fastigial nucleus (6.48 posterior, 0.75 left, 3.7 mm ventral from bregma) was injected with virus encoding Channelrhodopsin in a cre-dependent manner (AAV9-EF1a-double floxed-hChR2(H134R)-EYFP-WPRE-HGHpA, titer of 2.2×10 13 Addgene viral prep #202198-AAV9, lot #V22125, provided to Addgene by Karl Deisseroth)( ) consistent with our previously published methods for successful viral targeting of this nucleus ( ).

Techniques:

Journal: bioRxiv

Article Title: Distinct fastigial output channels and their impact on temporal lobe seizures

doi: 10.1101/2021.08.18.456836

Figure Lengend Snippet: On-demand optogenetic excitation of FN-SC neurons fails to attenuate hippocampal seizures. A) FN-SC output channel and experimental design schematics. Mice received dual viral injections and underwent epilepsy induction, followed by implantation of electrodes in the hippocampus and optic fibers in the fastigial nucleus for targeting FN-SC. B) Example seizure events detected (gray line) on-line that were randomly elected to either not receive light (top trace) or receive on-demand light delivery (bottom trace) to FN-SC neurons. Blue bar indicates timing of light delivery. C) Histograms of post-detection seizure durations for events not receiving light (hashed bars) versus those receiving light (blue bars) in an example animal with targeting of FN-SC neurons, illustrating no significant effect of light delivery on hippocampal seizure duration (p = 0.58, two sample Kolmogorov-Smirnov test). Inset indicates experimental schematic of viral targeting, electrode recording, and optogenetic stimulation. D) Population histograms of post-detection seizure durations across FN-SC mice (n=600 events, from six animals), showing no significant effect of light delivery (p = 0.46, two sample Kolmogorov-Smirnov test). Inset: 0 out of 6 FN-SC mice (p > 0.05, two sample Kolmogorov-Smirnov test) show a significant effect of light delivery (black circle indicates mean). E) Additional targeting strategy, using retrograde viral injection into the VL nucleus of the thalamus. F) Dual viral targeting of FN-VL neurons labels neurons in the caudal portion of the fastigial nucleus (inset shows higher magnification image), as well as fastigial fibers in both the VL nucleus (G, left) and SC (G, right). H) Example seizure events detected (gray line) on-line that were randomly elected to either not receive light (top trace) or receive on-demand light delivery (bottom trace) to FN-VL neurons. I) Seizure durations from an example animal with targeting of FN-VL neurons, illustrating no significant effect of light delivery (p = 0.67, two sample Kolmogorov-Smirnov test). J) Population histograms of post-detection seizure durations across FN-VL mice (n=400 events, from four animals), showing no significant effect of light delivery (p = 0.48, two sample Kolmogorov-Smirnov test). Inset: 0 out of 4 FN-VL mice show a significant effect of light delivery. Scale bars: 5 sec, 0.05mV (B, H); 500µm (F, inset 10µm); 100µm (G, left); 50µm (G, right).

Article Snippet: Following retrograde viral injection, the contralateral fastigial nucleus (6.48 posterior, 0.75 left, 3.7 mm ventral from bregma) was injected with virus encoding Channelrhodopsin in a cre-dependent manner (AAV9-EF1a-double floxed-hChR2(H134R)-EYFP-WPRE-HGHpA, titer of 2.2×10 13 Addgene viral prep #202198-AAV9, lot #V22125, provided to Addgene by Karl Deisseroth)( ) consistent with our previously published methods for successful viral targeting of this nucleus ( ).

Techniques: Injection

Journal: bioRxiv

Article Title: Distinct fastigial output channels and their impact on temporal lobe seizures

doi: 10.1101/2021.08.18.456836

Figure Lengend Snippet: On-demand optogenetic activation of FN-CL neurons robustly attenuates hippocampal seizures. A) FN-CL output channel and experimental schematic for targeting. B) Example seizure events detected (gray line) on-line that were randomly elected to either not receive light (top trace) or receive on-demand light delivery (bottom trace) to FN-CL neurons. Blue bar indicates timing of light delivery. C) Seizure durations from an example animal with targeting of FN-CL neurons, showing a significant effect of light delivery (p < 0.001, two sample Kolmogorov-Smirnov test). D) Population histograms of post-detection seizure duration events across FN-CL mice (n=700 seizure events, from seven mice), showing a significant effect of light delivery (p < 0.001, two sample Kolmogorov-Smirnov test). Inset: Normalized seizure duration for light versus no light across FN-CL mice, with 7 out of 7 mice (100%) showing a significant reduction at the animal level. Black dot denotes average. E) To directly target FN fibers in the CL nucleus, mice were injected in the fastigial nucleus with virus encoding channelrhodopsin, followed by intrahippocampal kainic acid for induction of epilepsy, and then implanted with electrodes in the hippocampus and optic fibers targeting the central lateral nucleus for on-demand interventions. F) Example detected seizure events that were randomly elected to either not receive light (top trace) or receive light delivery (bottom trace) to fastigial fibers in the CL nucleus. Blue bar indicates timing of light delivery. G) Population histograms of post-detection seizure duration events across FN-CL mice (n=1100 seizure events, from eleven mice), showing a significant effect of light delivery (p < 0.001, two sample Kolmogorov-Smirnov test). Inset: Normalized seizure duration for light versus no light across CL fiber targeting mice, with 7 out of 11 mice showing a significant reduction at the animal level. Block dot indicates average. H) No effect of light delivery to the CL is observed in control animals (n = 300 seizure events from 3 mice, p = 0.14, two sample Kolmogorov-Smirnov test). Scale bars: 5 sec, 0.05mV (B, F).

Article Snippet: Following retrograde viral injection, the contralateral fastigial nucleus (6.48 posterior, 0.75 left, 3.7 mm ventral from bregma) was injected with virus encoding Channelrhodopsin in a cre-dependent manner (AAV9-EF1a-double floxed-hChR2(H134R)-EYFP-WPRE-HGHpA, titer of 2.2×10 13 Addgene viral prep #202198-AAV9, lot #V22125, provided to Addgene by Karl Deisseroth)( ) consistent with our previously published methods for successful viral targeting of this nucleus ( ).

Techniques: Activation Assay, Injection, Virus, Blocking Assay, Control

Journal: Brain Sciences

Article Title: Bimodal Benefits for Lexical Tone Recognition: An Investigation on Mandarin-speaking Preschoolers with a Cochlear Implant and a Contralateral Hearing Aid

doi: 10.3390/brainsci10040238

Figure Lengend Snippet: Demographic information of the participants.

Article Snippet: S9 (F) , 5.6 , Nucleus6 (L) , ACE , Phonak Q90 SP , 3.3 , 2.3 , 3.3 , 2.3 , 56.

Techniques: