We conducted a comprehensive online search of the literature related to SCs using the Web of Science Core Collection database¹, and the search strategy is shown in Figure 1. The index, category, document type, language type, and time span of the search were refined and a total of 1,923 documents were retrieved, which were exported as “full record and cited references” or UTF-8 for further analysis.

We extracted the annual number of articles issued, citations, H-index, and the average number of citations per item (ACI) from the analysis of the results, and obtained the impact factor (IF) and quartile categories from the 2020 Journal Citation Report of the Web of Science database. The UTF-8 format data were imported into the bibliometric online analysis platform² for collaborative relationship analysis between countries/regions. For co-authorship as well as co-citation, co-occurrence, cluster, and burst analysis, we applied CiteSpace³ (Version 5.8.R3) and VOSviewer⁴ (Version 1.6.17) software to visualize bibliometric data, which were imported in “full record and cited reference” format. CiteSpace developed by Chen, as one of the most commonly used visual analysis software in bibliometrics, is used to observe research hotspots and trends in a specific field and visually present them in the form of a graph (Synnestvedt et al., 2005). VOSviewer, developed by Prof. van Eck and Waltman in 2009, can visualize scientific landscapes via network, coverage, or density maps (van Eck and Waltman, 2010).

After filtering by the above search process, 1,923 papers were included, including 1,548 articles and 375 reviews. The annual number of publications and citations from 2012 to 2021 is clearly shown in Figure 2. We can discover that from 2012 to 2020, the annual number of publications shows a small fluctuation, and the number of publications in 2021 decreases more. From the perspective of citations, the total citations were 42,625, and the remaining 36,542 after removing self-citations. From 2012 to 2021, the annual citations increased year by year, with the highest in 2021, reaching 8,512.

In Figure 3A, the number of papers published by different countries was shown, with the larger circles indicating more publications. We can observe from this that the United States (651), China (445), and Germany (227) are the top three countries with the highest number of publications. The cooperation between different countries/regions was presented in Figure 3B. Since the thicker the line between two countries means more cooperation between them, we can see that the United States cooperates most with other countries, and among them, Germany and China have a thicker line with the United States, which proves that the United States communicates more closely with them. In addition, according to Table 1, we conducted an analysis of funding agencies and found that the top three most prolific funding agencies were, the National Institutes Of Health (459), the United States Department Of Health Human Services (459), and the National Institute Of Neurological Disorders Stroke Ninds (311), notably, they are all from the United States, which emphasizes the influence of the United States in the field.

The publication counts, H-indexes, and ACIs of the top 10 most prolific institutions were displayed in Figure 4A. The top 5 institutions in terms of publication counts were League of European Research Universities (LERU) (150), Nantong University (117), the University of California system (61), and the University of London (59). H-index can be used to reflect the quantity and level of academic outputs (Miao et al., 2022). LERU ranked first in the H Index (41), followed by the University of London (26) and Washington University in St. Louis (WUSTL) in the United States (26). ACI is another tool for assessing the value of a paper (Wu et al., 2021). University College London (61.44), University of London (51.88), and WUSTL (36.6) were the top three institutions with the highest ACI, and LERU ranked fourth at 32.13. We can recognize from this that LERU and the University of London have stronger integrated competencies and have shown their influence in the field. It is worth thinking that Nantong University had a low H-index and ACI ranking despite the high number of publications. We suggested that Nantong University should strengthen cooperation with other countries and improve the quality of articles to increase its influence in this field. In addition, we quantified in Figure 4B the number of papers published per year by the top 10 prolific institutions. LERU had the highest number of publications in 2014 with a more stable overall fluctuation in publications per year, and the University of London had the highest number of 12 in 2012, but the number of publications started to decline in the following years, and importantly, in the last 5 years, both institutions showed a significant increase in publications in 2019, indicating SCs were more popular in 2019.

As shown in Figure 5A, the highest number of publications was Wang Y (38), followed by Feltri ML (29) and Gu XS (27). Feltri ML had the highest H-index of 17, followed by Gu XS and Wang Y. Also, the top three ACI were Feltri ML, Wrabetz L and Gu XS. We can conclude that Feltri ML was leading in terms of the number of publications, H-index, and ACI, which proved that he is an author of high authority in the field. His articles represent hot topics in a part of the field. For example, Feltri ML et al. recently found that CC2D1B, a member of the Lgd/CC2D1 protein family, plays a role in developmental myelination in the central nervous system and suggested that CC2D1B may be involved in gene regulation during myelination in optic oligodendrocytes (Acheta et al., 2022). The citation frequency is another important indicator to measure the influence, as Figure 5B shows, the larger the circle means the more citations. Jessen KR was cited much more frequently than other authors, ranked first, and cooperated closely with other authors, which also represented the great influence of Jessen KR in the field. Furthermore, in the coverage visualization map in Figure 5C, nodes are marked by different colors according to the average year of appearance, with authors appearing relatively early in the field closer to purple, and nodes marked in yellow are likely to represent authors with younger research in the field. We can observe that the author Min Qing, as well as Pan Deng, Snyder-Warwick, Alison k are new players in this field in recent years.

Papers related to SCs in neurosciences were published in 162 journals from 2012 to 2021. We listed the top ten journals in this field based on the number of publications, as demonstrated in Table 2. NEURAL REGENERATION RESEARCH was in the first place with 176 published articles, GLIA was in the second place with 163 articles, followed by JOURNAL OF NEUROSCIENCE with 124 articles. Besides, the JIF of a journal is another important parameter to evaluate the value of the journal itself and the publications included in it. Among the top 10 academic journals, GLIA had the highest JIF at 7.452, followed by JOURNAL OF NEUROSCIENCE at 6.167, and both were classified as Q1. Also, the top three cited journals were JOURNAL OF NEUROSCIENCE (4688), GLIA (3767), and EXPERIMENTAL NEUROLOGY (2821). Based on the above, we believe that GLIA and JOURNAL OF NEUROSCIENCE are the more authoritative journals in this field.

Citation analysis is an important indicator in bibliometric studies. Table 3 showed the top 10 most cited literatures, including 5 mechanistic studies (Gaudet et al., 2011; Jessen et al., 2015; Monk et al., 2015; Salzer, 2015; Jessen and Mirsky, 2016) and 5 experimental studies (Arthur-Farraj et al., 2012; Napoli et al., 2012; Stassart et al., 2013; Cattin et al., 2015; Gomez-Sanchez et al., 2015), which focused on the development and function of SCs. Interestingly, the top four most-cited papers were all written or directed by Jessen KR, who works at the University of London, reflecting Jessen KR’s great influence in the field. Citation bursts refer to references that caught the attention of scholars in a specific field at a specific time interval, and whose analysis can be used to observe the evolution of a field of knowledge and to predict frontier trends. In Figure 6, the timeline was shown in blue and the interval at the time of the burst was shown in red, indicating the start year, the end year, and the duration of the burst. Of these burst citations, the shortest burst duration for SCs-related publications in neurosciences was 1 year and the longest was 4 years. Notably, the 40% citation burst ended in 2021 or later, which focused on new advances in SCs in myelin clearance and remyelination (Cattin et al., 2015; Gomez-Sanchez et al., 2015; Jessen et al., 2015; Salzer, 2015; Brosius Lutz et al., 2017; Clements et al., 2017; Gomez-Sanchez et al., 2017) as well as transcription factors, epigenetic mechanisms and signaling cascades that regulate the repair SCs (Jessen and Mirsky, 2016; Arthur-Farraj et al., 2017; Jessen and Arthur-Farraj, 2019), suggesting that these research topics have been receiving attention in recent years and are expected to be a focus for researchers in the future.

The modularity value (Q value) and the average silhouette value (S value) are two important parameters to evaluate the importance of cluster structure, and when Q > 0.3 and S > 0.7, it indicates that the clusters are significant. In this study, it can be evidenced from Figure 7A that the Q value was 0.8235 and the mean S value was 0.9702, indicating that these clusters are effective. The top five clusters were displayed in the figure which were, “polysialic acid” (#0), “Guillain-barre syndrome (GBS)” (#1), “Wallerian degeneration” (#2), “Charcot–Marie–tooth disease (CMT)” (#3), and “neuromuscular junction” (#4). For further study, the timeline view was shown in Figure 7B, with the bold timeline indicating that the clustering topic was a hot spot during this period. In particular, polysialic acid, GBS, and CMT were hot until 2021 and will probably last until today. GBS and CMT as demyelinating diseases are greatly associated with SCs, and SCs are being investigated as therapeutic agents for demyelinating diseases, and further sorting out the function of SCs will help in the development of treatment (Bhatheja and Field, 2006; Moss et al., 2021). We again performed the analysis of keyword co-occurrence by using VOSviewer’s coverage visualization map. As shown, trigeminal nerve, transcriptome, and immune response are the emerging hot keywords in recent years in Figure 7C. Reported that the immune response plays an important role in the early stages after nerve injury, transcriptome analysis is now often used to further investigate the molecular mechanisms of the immune response after peripheral nerve injuries to provide a scientific basis for more effective treatment of peripheral nerve injuries (He et al., 2021).