Research progress has been made in the coding of neurons in the posterior cingulate gyrus of rhesus monkeys for their own motor perception

eLife published a research paper titled "Vestibular Signals in the Posterior Cinging Gyrus of Rhesus Monkeys Encoding Self-Motion Perception".
The research was sponsored by the Chinese Academy of Sciences Brain Science and Intelligent Technology Excellence Innovation Center (Neuroscience Institute), Shanghai Brain Science and Brain-like Published by the Research Center of Space Perception, the Key Laboratory of Primate Neurobiology of the Chinese Academy of Sciences.
The study uses virtual reality system and extracellular electrophysiological technology in awake rhesus monkeys to explore how neurons located in the posterior cingulate gyrus region of the macaque brain encode their own information based on their own motor perception, and find that the posterior cingulate gyrus subregion in this region carries Vestibular signals with clear spatio-temporal tuning properties, and through the three-dimensional spatio-temporal dynamic model to effectively separate the different time components of its own motion, the dynamic analysis of the time and space modulation of the vestibular information carried in the region is carried out.

When organisms conduct space exploration activities, common strategies are based on landmark-based navigation and vector-based navigation.
Among them, when there is a lack of effective external road signs or the road signs are too fuzzy, the organism mainly relies on the latter (also called path integration) to navigate the space.
At this time, the vestibular information based on its own motion and the optical flow (Optic flow) ) Visual information plays an important role in it.
As the navigation system in the animal brain, the hippocampus area plays a key role in the spatial navigation method of path integration.
However, it is not yet known how the hippocampus uses the outside world's own motion information to encode path integrals.
In previous studies, researchers have discovered the coding of vestibular information and optical flow visual information in multiple sensory brain areas (mainly located in the temporal and parietal lobes) of the neocortex of the macaque brain, but these areas are not directly related to the hippocampus system.
The structural connection.

Previous studies have shown that the posterior cingulate gyrus area above the corpus callosum is in the middle zone between the sensory cortex and the hippocampus system, which encodes information about its own motion.
Therefore, to find its own motion information, it is transmitted to the hippocampal path integral navigation system.
In the brain area that plays a role as a bridge in the process, the Gu Yong group researchers used a mature virtual reality system and used a six-degree-of-freedom motion platform to give almost evenly distributed 26 different directions of motion stimulation and use light in a three-dimensional space.
The visual motor stimulus of flow simulation explores the coding of the neurons in the posterior cingulate gyrus region, which is in the middle of the structure, to their own motion information.
The vestibular system of a living body is composed of two parts: the otolith apparatus and the semicircular canal.
The former mainly encodes linear acceleration (translation signal), and the latter encodes rotational movement.
In order to explore the similarities and differences between the two encodings of neurons, motor stimuli were given under the conditions of translation and rotation.
The researchers used extracellular electrophysiological recording to record separately in two different subregions of macaques-the posterior cingulate gyrus cortex and the posterior compression cortex, and found that the posterior cingulate gyrus cortex has a strong vestibular signal in its own movement perception.
The coding, and has complex spatio-temporal tuning properties.
Compared with the posterior cingulate cortex, the posterior compression cortex, which is in the deeper part of the brain, also encodes vestibular signals, but its coding characteristics do not include clear spatiotemporal tuning properties.

In order to quantitatively analyze the nature of the space-time tuning, the researchers used a three-dimensional space-time dynamics model to decompose the time and space components of the motion stimulus, and found that the neuron population in this brain region encodes acceleration, velocity, variable acceleration, and position.
This time component indicates that the acceleration signal from the peripheral organs of the vestibule has undergone different degrees of integration and differentiation calculations in the process of being transmitted to the brain area in order to be used for different functions.
In addition, this brain area carries more acceleration components in the vestibular stimulus of translational motion, while the vestibular information encoding in the rotation stimulus is more biased towards speed signals.
Combined with the distribution of the preference direction of the neuron population, it indicates the brain area The rotation signal may act on the head direction cell of the hippocampus.
In addition, although both sub-regions of this region encode strong vestibular signals, the weaker visual information coding means that this region does not seem to encode two kinds of self-motion information at the same time.
This work is of great significance in the coding research of vestibular information in the brain network, and provides a good foundation for further exploring the information transmission of vestibular information from the upstream sensory cortex to the downstream hippocampal navigation system.
(Bioon.
com)