Cell: Xue Tian/Bao Jin's team revealed the neural mechanism of light perception to promote brain development

The sensory stimuli (including vision, hearing, touch, etc.

Previous studies have shown that rearing in complete darkness after birth leads to a slowdown in synapse formation across multiple sensory cortices in young mice, and the neuropeptide oxytocin may be a key molecule in mediating this process

On August 8, 2022, Professor Xue Tian from the Department of Life Science and Medicine of the University of Science and Technology of China, and Bao Jinte's researcher team published a research paper in the journal Cell titled: Melanopsin retinal ganglion cells mediate light-promoted brain development, exploring light-promoted brain development.

Visual perception in mammals begins in the retina

The research team firstly knocked out Opn4, the gene encoding the photoreceptor protein of ipRGCs, and found that the neonatal mice lacking the photoreceptor ability of ipRGCs (Opn4-/-) had spontaneous small excitability in multiple sensory cortex and hippocampal vertebral neurons in the early postnatal development.

This result suggests that ipRGCs may mediate the phenomenon of light-promoted brain synaptogenesis after birth

In order to further explore the circuits and molecular mechanisms by which the light perception of ipRGCs promotes cortical and hippocampal synaptogenesis, the researchers used mass spectrometry detection, neonatal mouse brain and retinal nerve tracing and regulation, and found that when ipRGCs were activated by light, they would pass through the retina.

Figure 1: Light perception mediated by ipRGCs in early development promotes synaptic synapses in different higher cognitive regions of the brain (cerebral cortex, hippocampus, etc.

) by activating oxytocin neurons in the supraoptic nucleus (SON) and paraventricular nucleus (PVN).
co-development
.
To explore the effects of light-facilitated brain synapse development during early development on higher-level brain cognitive abilities in adulthood, the researchers trained mice to learn the correlation between different frequencies of sound stimulation and reward/punishment (Go/No-go behavior), It was found that the loss of photoreceptor in ipRGCs in childhood led to a significant decrease in the learning speed of mice in adulthood (Fig.
2), and this deficit in adult learning ability can be caused by artificial activation of ipRGCs or oxytocin neurons in the supraoptic nucleus during childhood.
rescued
.
Figure 2: Light perception mediated by ipRGCs early in development enhances learning in adult mice
.

(The schematic diagram was perfected by Mr.
Liu Hui from the School of Humanities and Social Sciences, University of Science and Technology of China.
) In
conclusion, this study discovered the photoreceptor and neural circuits that promote the coordinated development of neuronal synapses in the higher cognitive regions of the brain in early developmental visual (light) perception.
and molecular mechanisms, and reveal the impact of early developmental light perception on higher cognitive abilities in the adult brain
.

The results of this study suggest that public health research should pay attention to the daily light environment of neonates and further explore the impact of light environment on neonatal brain development
.
The research team said that in the next step, the team will continue to further explore the impact of light input in early development on mammalian health and survival, and provide scientific evidence for optimizing the environment for neonatal growth and development
.

Paper link: