In the cortex of a marmoset model of autism exposed to valproic acid in utero, genes associated with neurons and oligodendrocytes were down-regulated, and genes associated with microglia and astrocytes were up-regulated, as in human autism. However, the current major rodent models could only reproduce human autism in at most two of the four cell types of the brain. This confirms the prediction that primate autism models reproduce human autism better than rodent models by an objective method of transcriptome comparison.

The common marmoset (Callithrix jacchus), a small New World primate, is receiving substantial attention in the neuroscience and biomedical science fields because its anatomical features, functional and behavioral characteristics, and reproductive features and its amenability to available genetic modification technologies make it an attractive experimental subject. This review outlines the progress of marmoset neuroscience research and summarizes both the current status (opportunities and limitations) of and the future perspectives on the application of marmosets in neuroscience and disease modeling.

The researchers generated a new Alzheimer’s disease (AD) mouse model that more faithfully recapitulate pathology of AD patients compared to the previous ones. This new third-generation mouse model will help accelerate the elucidation of the disease mechanisms and development of disease-modifying therapies to treat AD.

By recording neuronal activity from a Japanese monkey model of Parkinson’s disease, the researchers have elucidated the neural mechanisms underlying parkinsonian symptoms. Disturbance of information flow through the “direct pathway” in the basal ganglia is responsible for parkinsonian symptoms, and its restoration has beneficial effects on the symptoms.

The researchers demonstrated that auditory gamma oscillation is globally distributed among the temporal, parietal, and frontal cortices by using intracranial recordings implanted for the diagnostic purpose of the intractable epilepsy. Elucidation of the mechanism of gamma oscillation, which is decreased in psychiatric disorders such as schizophrenia, is expected to be useful for the development of future diagnosis and treatment.

Comprehensive expression analysis of genes associated with developmental disorders and psychiatric disorders in the common marmoset brain revealed that these genes are expressed in a specific brain region. Also, by comparing the expression patterns of the mouse and human brain, it was clarified that there are many common expression patterns between marmosets and humans.

The researchers performed comprehensive DNA methylation analyses of neurons from patients with bipolar disorder, and found that many genes were hypomethylated in patients, while genes important for neuronal function were hypermethylated. Differentially methylated regions in neurons were significantly enriched in genomic regions suggested by a genome-wide association study of bipolar disorder, indicating an association with genetic factors.