Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Dec 6;20(1):570.
doi: 10.1186/s12967-022-03787-9.

Continuous high-frequency deep brain stimulation of the anterior insula modulates autism-like behavior in a valproic acid-induced rat model

Lifei Xiao #  1   2 , Shucai Jiang #  3 , Yangyang Wang #  1 , Caibin Gao  2 , Cuicui Liu  4 , Xianhao Huo  1   2 , Wenchao Li  1 , Baorui Guo  5 , Chaofan Wang  1 , Yu Sun  1 , Anni Wang  1 , Yan Feng  1 , Feng Wang  6 , Tao Sun  7   8
Affiliations

Continuous high-frequency deep brain stimulation of the anterior insula modulates autism-like behavior in a valproic acid-induced rat model

Lifei Xiao et al. J Transl Med. .

Abstract

Background: Until now, the treatment of patients with autism spectrum disorder (ASD) remain a difficult problem. The insula is involved in empathy and sensorimotor integration, which are often impaired in individuals with ASD. Deep brain stimulation, modulating neuronal activity in specific brain circuits, has recently been considered as a promising intervention for neuropsychiatric disorders. Valproic acid (VPA) is a potential teratogenic agent, and prenatal exposure can cause autism-like symptoms including repetitive behaviors and defective sociability. Herein, we investigated the effects of continuous high-frequency deep brain stimulation in the anterior insula of rats exposed to VPA and explored cognitive functions, behavior, and molecular proteins connected to autism spectrum disorder.

Methods: VPA-exposed offspring were bilaterally implanted with electrodes in the anterior insula (Day 0) with a recovery period of 1 week. (Day 0-7). High-frequency deep brain stimulation was applied from days 11 to 29. Three behavioral tests, including three-chamber social interaction test, were performed on days 7, 13, 18, 25 and 36, and several rats were used for analysis of immediate early genes and proteomic after deep brain stimulation intervention. Meanwhile, animals were subjected to a 20 day spatial learning and cognitive rigidity test using IntelliCage on day 11.

Results: Deep brain stimulation improved the sociability and social novelty preference at day 18 prior to those at day 13, and the improvement has reached the upper limit compared to day 25. As for repetitive/stereotypic-like behavior, self- grooming time were reduced at day 18 and reached the upper limit, and the numbers of burried marbles were reduced at day 13 prior to those at day 18 and day 25. The improvements of sociability and social novelty preference were persistent after the stimulation had ceased. Spatial learning ability and cognitive rigidity were unaffected. We identified 35 proteins in the anterior insula, some of which were intimately linked to autism, and their expression levels were reversed upon administration of deep brain stimulation.

Conclusions: Autism-like behavior was ameliorated and autism-related proteins were reversed in the insula by deep brain stimulation intervention, these findings reveal that the insula may be a potential target for DBS in the treatment of autism, which provide a theoretical basis for its clinical application., although future studies are still warranted.

Keywords: Autism spectrum disorder; Deep brain stimulation; Insula cortex; Proteomics; Valproic acid.

PubMed Disclaimer

Conflict of interest statement

The authors have stated that there are no competing interests.

Figures

Fig. 1
Fig. 1
Deep brain stimulation system and electrodes implantation in rat anterior insula. A Electrical stimulation pattern of bilateral insular cortex in rats. Program controller was used to adjust parameters of IPG through the signal converter. B Photograph of the DBS apparatus consisting of an implantable pulse generator (IPG) and two electrodes. C A schematic view of the sagittal rat brain section showing the target of electrode implantation. D Targets of implanted electrodes (colored dots) in the AI of rats included for behavioural data analysis (n = 67). Experiment 1: saline-sham (green), n = 13; saline-DBS (yellow), n = 13; VPA-sham (orange), n = 12; VPA-DBS (red), n = 14. Experiment 2: saline-sham (blue), n = 5; saline-DBS (purple), n = 5; VPA-DBS (black), n = 5. E Experimental timeline. Six-week-old male saline- and VPA-exposed offspring were bilaterally implanted with DBS system (Day 0) followed by a 7 day recovery. HF-DBS (120 Hz, 150 µA, 90 µs) was continuously applied for 18 days (Day 11–29) and turned off on day 29. The autism-like related behavioural tests were performed on day 7, 13, 18, 25 and 36. The spatial learning and cognitive rigidity tests were performed on day 11 for 20 days. IPG implantable pulse generator, GI granular insular cortex, DI dysgranular insular cortex, AI agranular insular cortex. The schematic diagrams of rat brain coronal sections were adapted from the atlas of Paxinos and Watson [27]
Fig. 2
Fig. 2
HF-DBS improved the social ability in the VPA-exposed offspring. In three-chamber social interaction test: A Time spent by test rats in chamber S1. B Time spent by test rats in chamber S2. C Sniffing time between test rats and S1. D Sniffing time between test rats and S2. E Sociability index. F Social novelty preference index. G Representative heat maps of three-chamber social interaction test on day 18. Data are shown as mean with SD. Two-way repeated ANOVA with post-hoc Bonferroni test, *p < 0.05 vs. saline; **p < 0.01 vs. saline; ***p < 0.001 vs. saline; #p < 0.05 vs. VPA; ##p < 0.01 vs. VPA; ###p < 0.001 vs. VPA
Fig. 3
Fig. 3
When HF-DBS was turned off for 7 days (Day 36), HF-DBS still reversed the decreased social interaction. A Time spent by test rats in Chamber S1 on day 36. B Time spent by test rats in Chamber S2 on day 36. C Sniffing time between test rats and S1 on day 36. D Sniffing time between test rats and S2 on day 36. E Sociability index on day 36. F Social novelty preference index on day 36. Data are shown as mean with SD. One-way ANOVA with post-hoc Tukey's test, *p < 0.05 vs. saline; **p < 0.01 vs. saline; ***p < 0.001 vs. saline; #p < 0.05 vs. VPA. HF-DBS alleviated the excessive repetitive behavior in the VPA-exposed offspring. G Total distance travelled by test rats. H Number of self-grooming behavior. I Duration of self-grooming behavior. Two-way repeated ANOVA with post-hoc Bonferroni test, *p < 0.05 vs. saline; **p < 0.01 vs. saline; ***p < 0.001 vs. saline; #p < 0.05 vs. VPA; ##p < 0.01 vs. VPA; ###p < 0.001 vs. VPA
Fig. 4
Fig. 4
When HF-DBS was turned off for 7 days (Day 36), the effect of HF-DBS on repetitive behavior was weakened. A Total distance travelled by test rat on day 36. B Number of self-grooming behavior on day 36. C Duration of self-grooming behavior on day 36. One-way ANOVA with post-hoc Tukey’s test, *p < 0.05 vs. saline; #p < 0.05 vs. VPA. HF-DBS reversed the repetitive/stereotypic-like activities in marble burying test: D Number of marbles buried. Data are shown as mean with SD. Two-way repeated ANOVA with post-hoc Bonferroni test, **p < 0.01 vs. saline; ***p < 0.001 vs. saline; ##p < 0.01 vs. VPA; ###p < 0.001 vs. VPA. E Number of marbles buried on day 36. Data are shown as mean with SD. one-way ANOVA with post-hoc Tukey's test, ***p < 0.001 vs. Saline. There is no significant effect on spatial learning ability and cognitive rigidity in the VPA-exposed offspring. F Number of total corner visits in phase 1. G Lick dutation of all corners in phase 1. H Number of total corner visits in phase 2. I Ratio of the number of correct corner visits to the number of total corner visits in phase 3. J Ratio of the number of correct corner visits to the number of total corner visits in phase 4. Data are shown as mean with SD. Ono-way ANOVA with post-hoc Tukey's test, * p < 0.05 vs. saline; ** p < 0.01 vs. saline; *** p < 0.001 vs. saline. K Representative marbles buried maps of marbel burying test on day 18
Fig. 5
Fig. 5
A Expression levels of immediate early genes in the insular cortex, including c-Fos, c-Jun, Arc, Naps4. **p < 0.01 vs. saline; ##p < 0.01 vs. VPA; ###p < 0.001 vs. VPA. B Volcano plot demonstrating proteins differentially regulated in VPA compared to saline. Each data point represents a single quantified protein. Proteins in blue indicate for downregulation and in red indicate for upregulation in VPA. The abscissa of the volcano graph is log2 (FC), the farther the value from zero, the greater the difference, with upregulation on the right and downregulation on the left. The ordinate is -log10 (P-value), and the farther the ordinate value from zero, the greater the difference. C Heat map showing the up- and down-regulated proteins with a p value  < 0.05 and  ≥ 1.5-fold change between saline and VPA
Fig. 6
Fig. 6
A GO analysis of the significant proteins on their biological process, B molecular function and C cellular component. Yellow indicates the up-regulated and green the down-regulated terms. Bubble chart of the KEGG enrichment analysis. The x-axis is the enrichment score and the y-axis is the pathway terms. The size of the bubbles reflects the number of differentially expressed proteins. The larger the bubble, the greater the number of differentially expressed proteins. The lower the P-value, the higher the significance of the KEGG pathway enrichment. D Enrichment pathways screened among total differentially expressed proteins. E Enriched pathways screened among up-regulated proteins. F Enriched pathways screened among down-regulated proteins. G PPI of 20 hub proteins. In hub protein analysis, the darker the color, the higher the score. KEGG Kyoto Encyclopedia of Genes and Genomes, GO Gene Ontology, PPI protein-protein interaction
Fig. 7
Fig. 7
A Venn diagram of 20 hub DEPs and SFARI gene database. ↑, upregulated; ↓, downregulated. B KEGG pathways screened among 20 hub proteins. C GO analysis of 20 hub proteins. D Cluster map of Mfuzz expression patterns. The left side of the figure is a line graph of protein expression, and the right side is a heat map of protein expression. Each cluster corresponds to a line graph and a heatmap. The kegg pathway and GO enrichment information are shown to the right of the corresponding heatmap. E Venn diagram among DEPs of VPA versus saline batches (56 DEPs), DEPs after DBS intervention (35 DEPs) and the SFARI gene database. KEGG Kyoto Encyclopedia of Genes and Genomes, GO Gene Ontology
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Lord C, Brugha TS, Charman T, et al. Autism spectrum disorder. Nat Rev Dis Primers. 2020;6:5. doi: 10.1038/s41572-019-0138-4. - DOI - PMC - PubMed
    1. Robertson CE, Baron-Cohen S. Sensory perception in autism. Nat Rev Neurosci. 2017;18:671–84. doi: 10.1038/nrn.2017.112. - DOI - PubMed
    1. Baxter AJ, Brugha TS, Erskine HE, et al. The epidemiology and global burden of autism spectrum disorders. Psychol Med. 2015;45:601–13. doi: 10.1017/S003329171400172X. - DOI - PubMed
    1. Chaste P, Leboyer M. Autism risk factors: genes, environment, and gene-environment interactions. Dialogues Clin Neurosci. 2012;14:281–92. doi: 10.31887/DCNS.2012.14.3/pchaste. - DOI - PMC - PubMed
    1. Sharma SR, Gonda X, Tarazi FI. Autism spectrum disorder: classification, diagnosis and therapy. Pharmacol Ther. 2018;190:91–104. doi: 10.1016/j.pharmthera.2018.05.007. - DOI - PubMed

Publication types

-