Hand-Rearing Method for Infant Marmosets

The common marmoset (Callithrix jacchus) is a small and highly social New World monkey with high reproduction rates, which has been proven to be a ...

Zhejiang University

Temporal processing is crucial for auditory perception and cognition, especially for communication sounds. Previous studies have shown that the auditory cortex and the thalamus use temporal and rate representations to encode slowly and rapidly changing time-varying sounds. However, how the primate inferior colliculus (IC) encodes time-varying sounds at the millisecond scale remains unclear. In this study, we investigated the temporal processing by IC neurons in awake marmosets to Gaussian click trains with varying interclick intervals (2-100 ms). Strikingly, we found that 28% of IC neurons exhibited rate representation with nonsynchronized responses, which is in sharp contrast to the current view that the IC only uses a temporal representation to encode time-varying signals. Moreover, IC neurons with rate representation exhibited response properties distinct from those with temporal representation. We further demonstrated that reversible inactivation of the primary auditory cortex modulated 17% of the stimulus-synchronized responses and 21% of the nonsynchronized responses of IC neurons, revealing that cortico-colliculus projections play a role, but not a crucial one, in temporal processing in the IC. This study has significantly advanced our understanding of temporal processing in the IC of awake animals and provides new insights into temporal processing from the midbrain to the cortex.

Corticofugal modulation of temporal and rate representations in the inferior colliculus of the awake marmoset.

Cortical feedback has long been considered crucial for the modulation of sensory perception and recognition. However, previous studies have shown varying modulatory effects of the primary auditory cortex (A1) on the auditory response of subcortical neurons, which complicate interpretations regarding the function of A1 in sound perception and recognition. This has been further complicated by studies conducted under different brain states. In the current study, we used cryo-inactivation in A1 to examine the role of corticothalamic feedback on medial geniculate body (MGB) neurons in awake marmosets. The primary effects of A1 inactivation were a frequency-specific decrease in the auditory response of most MGB neurons coupled with an increased spontaneous firing rate, which together resulted in a decrease in the signal-to-noise ratio. In addition, we report for the first time that A1 robustly modulated the long-lasting sustained response of MGB neurons, which changed the frequency tuning after A1 inactivation, e.g. some neurons are sharper with corticofugal feedback and some get broader. Taken together, our results demonstrate that corticothalamic modulation in awake marmosets serves to enhance sensory processing in a manner similar to center-surround models proposed in visual and somatosensory systems, a finding which supports common principles of corticothalamic processing across sensory systems.

Selective corticofugal modulation on sound processing in auditory thalamus of awake marmosets.

The use of assisted reproductive technology (ART) has risen steadily worldwide over the past 3 decades and helps many infertile families. However, ART treatments lead to an abnormal internal environment in the uterus, which may increase the risks of health problems for the offspring. Higher maternal estradiol (E) is a notable feature in women who use ART treatments, and this has been suggested as a key factor for the risk of diseases in the offspring. In the current study, we have established a marmoset model with a high E level in early pregnancy to examine its potential risk to the development and behavior of the offspring. In comparison with the normal group, babies of the high E group exhibited lower average survival rates and birth weights. However, those who survived in the high E group demonstrated normal vocal production with rich call repertoires, normal speed during locomotion, and normal behaviors in the home cage. In contrast to the normal group, surviving babies of the high E group spent more time sleeping during development without signs of sleep disorders. In summary, our study revealed that high estrogen in early pregnancy may cause low survival rates and birth weights of the offspring, though the surviving infants did not show obvious behavioral deficiencies during development. The current study is a valuable and highly important non-human primate study for evaluating the safety of ART treatments. However, it is worth noting that some results did not reach the significant level, which may be due to the small sample size caused by animal shortage stemming from the COVID-19 epidemic.

Effect of a High Estrogen Level in Early Pregnancy on the Development and Behavior of Marmoset Offspring.

Rhubarb is widely distributed and cultivated worldwide, and its leaves presented antioxidant activity and could be used as food additive. However, the chemical ingredients, and protective effect of Rheum officinale leaf juice (JROL) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) are still unclear.

The chemical composition, protective effect of Rheum officinale leaf juice and its mechanism against dextran sulfate sodium-induced ulcerative colitis.

In recent years, there has been increasing interest in studying gut microbiome-derived hydrolases in relation to oral drug metabolism, particularly focusing on natural product drugs. Despite the significance of natural product drugs in the field of oral medications, there is a lack of research on the regulatory interplay between gut microbiome-derived hydrolases and these drugs. This review delves into the interaction between intestinal microbiome-derived hydrolases and natural product drugs metabolism from three key perspectives. Firstly, it examines the impact of glycoside hydrolases, amide hydrolases, carboxylesterase, bile salt hydrolases, and epoxide hydrolase on the structure of natural products. Secondly, it explores how natural product drugs influence microbiome-derived hydrolases. Lastly, it analyzes the impact of interactions between hydrolases and natural products on disease development and the challenges in developing microbial-derived enzymes. The overarching goal of this review is to lay a solid theoretical foundation for the advancement of research and development in new natural product drugs and personalized treatment.

Gut microbiome-derived hydrolases-an underrated target of natural product metabolism.

Covering: up to 2024.Parasites infect hundreds of millions of people, result in significant disability rates and mortality and lead to devastating social and economic consequences, especially in developing countries and regions. Traditional medicines have been used for centuries to treat parasitic diseases. Some natural products (NPs) and their derivatives have been derived from these medicines and applied in clinical settings, attracting the attention of the scientific community throughout history. With the development and application of revolutionized technologies over the past few years, more promising compounds have been found from natural resources and provided new possibilities for the development of novel antiparasitic drugs. In this review, we aimed to discuss the strategies used for developing drugs from natural resources and mainly describe the causative pathogens, epidemiology and current treatment of parasitic diseases. Promising NPs and their derivatives are listed, and their effectiveness, potential mechanism and structural optimization are described. Subsequently, the advantages and limitations of the drug development process and the role of technologies in this process are discussed. A prospective analysis of research on and development of antiparasitic drugs based on NPs is presented. The high attrition rates, accessibility, sustainable supply, IP constraints and other problems still hinder the development of NPs; however, the therapeutic significance and broad clinical utilization of approved natural product-derived drugs, exemplified by quinine, artemisinin, and ivermectin in treating parasitic diseases, underscore that natural products remain a highly promising reservoir of chemical agents. Their exceptional structural diversity and marked bioactivities continue to stimulate scientific interest in novel antiparasitic drug discovery. In combination with the recent development and application of revolutionized technologies, NPs will provide a stronger basis for drug discovery and will continue to provide major contributions to human and veterinary health.

Article	Year
Corticofugal modulation of temporal and rate representations in the inferior colliculus of the awake marmoset. Cerebral cortex (New York, N.Y. : 1991)\| PubMed ID: 35029654	2022
Selective corticofugal modulation on sound processing in auditory thalamus of awake marmosets. Cerebral cortex (New York, N.Y. : 1991)\| PubMed ID: 35851798	2023
Effect of a High Estrogen Level in Early Pregnancy on the Development and Behavior of Marmoset Offspring. ACS omega\| PubMed ID: 36278046	2022
The chemical composition, protective effect of Rheum officinale leaf juice and its mechanism against dextran sulfate sodium-induced ulcerative colitis. Phytomedicine : international journal of phytotherapy and phytopharmacology\| PubMed ID: 38688143	2024
Gut microbiome-derived hydrolases-an underrated target of natural product metabolism. Frontiers in cellular and infection microbiology\| PubMed ID: 38915922	2024
Natural products in antiparasitic drug discovery: advances, opportunities and challenges. Natural product reports\| PubMed ID: 40501439	2025

Xinyuan Cao

Biography

JoVE Journal Publications

Other Publications