CELF4 regulates spine formation and depression-like behaviors of mice.

Chronic social stress is closed related to major depressive disorder, torturing millions of people and may destroy their lives. The prefrontal cortex is one of the core brain areas involved in pathological development and behavior changes in depression. CELF4 is a neuronal RNA-binding protein and plays an essential role in RNA processing. It is closely related to some neurological disorders, including seizures and neuroticism. Most recently, GWAS analysis indicates it is one of the significant genes associated with depression. Nonetheless, we are still unknown whether and how CELF4 gets involved in depression. Here, we reported that the protein and mRNA expression levels of CELF4 in the PFC were decreased in the CSDS depression model, as well as the spine number. Furthermore, we disturbed CELF4 expression in the PFC by using the AAV-shCELF4 virus. Unexpectedly, the spine number showed a decrease in PFC because of the impaired CELF4 expression, and the AAV-shCELF4 mice displayed depression-like behaviors. Our results suggest that CELF4 is critical for spine number and acts a critical role in depression-like behaviors of mice.

The Neural Mechanism of Number Line Bisection: A fMRI study.

The neural networks involved in number line bisection are poorly understood. We used functional magnetic resonance imaging (fMRI) to investigate these. fMRI was analyzed from 28 healthy volunteers who performed number and physical line bisection tasks (and their respective baselines). Whole brain analyses showed that these two bisection tasks shared common neural correlates in bilateral parietal-frontal networks; furthermore, bilateral parietal-frontal areas, right cerebellum, left insula and supplementary motor area (SMA) showed higher activity when contrasting the number line with a physical line bisection task. Importantly, psychophysiological interaction (PPI) analyses further indicated that left SMA and right cerebellum were connected to parietal-frontal areas for implementing the number line bisection task. Our findings suggested that a visuospatial attention control system was recruited, and mental imagery of a number line was used to find the midpoint of a numerical interval without calculations.

Addition and Subtraction but Not Multiplication and Division Cause Shifts of Spatial Attention.

Many studies have shown that solving addition and subtraction problems can induce overt shifts of spatial attention. In particular, right-side targets are detected faster than left-side targets when preceded by an addition operation, while left-side targets are detected faster than right-side targets when preceded by a subtraction operation. However, the interaction between space and arithmetic in multiplication or division is hardly studied and remains controversial. In order to make a strong case for the interaction between space and mental arithmetic, we attempted to replicate the spatial-arithmetic association in addition and subtraction (Experiment 1), and at the same time investigated whether shift of spatial attention would also be induced by multiplication or division operations (Experiment 2). We found that solving addition problems facilitated the detection of right-side targets, whereas left-side targets were detected faster after solving subtraction problems. However, no interaction between space and arithmetic operation was observed in multiplication or division. The implication of these findings is discussed.

The Time Course of Spatial Attention Shifts in Elementary Arithmetic.

It has been proposed that elementary arithmetic induces spatial shifts of attention. However, the timing of this arithmetic-space association remains unknown. Here we investigate this issue with a target detection paradigm. Detecting targets in the right visual field was faster than in the left visual field when preceded by an addition operation, while detecting targets in the left visual field was faster than in the right visual field when preceded by a subtraction operation. The arithmetic-space association was found both at the end of the arithmetic operation and during calculation. In contrast, the processing of operators themselves did not induce spatial biases. Our results suggest that the arithmetic-space association resides in the mental arithmetic operation rather than in the individual numbers or the operators. Moreover, the temporal course of this effect was different in addition and subtraction.

Dissociated Spatial-Arithmetic Associations in Horizontal and Vertical Dimensions.

Spatial-numerical associations (small numbers-left/lower space and large numbers-right/upper space) are regularly found in elementary number processing. Recently, the interest in this phenomenon has been extended from elementary number processing to mental arithmetic. Many studies have demonstrated horizontal spatial-arithmetic associations, i.e., solving addition or subtraction problems cause spatial shifts of attention rightward or leftward, respectively. However, the role of this effect in the vertical dimension has not been addressed. This is problematic because it leaves the analogy between elementary number processing and arithmetic incomplete. In order to make a strong case for a similarity between elementary number processing and mental arithmetic, a spatial-arithmetic association should be observed in the vertical dimension too. Here, we adopted the target detection paradigm from Liu et al. (2017) to replicate the horizontal spatial-arithmetic association, and meanwhile investigate whether this effect also exists in the vertical direction. Our results confirmed that addition could induce covert movement to right side and subtraction to left side. However, such a spatial-arithmetic association was not found in the vertical dimension. The implication of these findings is discussed.