Leukemia inhibitory factor impairs structural and neurochemical development of rat visual cortex in vivo

Anxiolytic effect of antidiabetic metformin is mediated by AMPK activation in mPFC inhibitory neurons

Diabetic patients receiving the antidiabetic drug metformin have been observed to exhibit a lower prevalence of anxiety disorders, yet the precise mechanism behind this phenomenon is unclear. In our study, we found that anxiety induces a region-specific reduction in AMPK activity in the medial prefrontal cortex (mPFC). Concurrently, transgenic mice with brain-specific AMPK knockout displayed abnormal anxiety-like behaviors. Treatment with metformin or the overexpression of AMPK restored normal AMPK activity in the mPFC and mitigated social stress-induced anxiety-like behaviors. Furthermore, the specific genetic deletion of AMPK in the mPFC not only instigated anxiety in mice but also nullified the anxiolytic effects of metformin. Brain slice recordings revealed that GABAergic excitation and the resulting inhibitory inputs to mPFC pyramidal neurons were selectively diminished in stressed mice. This reduction led to an excitation-inhibition imbalance, which was effectively reversed by metformin treatment or AMPK overexpression. Moreover, the genetic deletion of AMPK in the mPFC resulted in a similar defect in GABAergic inhibitory transmission and a consequent hypo-inhibition of mPFC pyramidal neurons. We also generated a mouse model with AMPK knockout specific to GABAergic neurons. The anxiety-like behaviors in this transgenic mouse demonstrated the unique role of AMPK in the GABAergic system in relation to anxiety. Therefore, our findings suggest that the activation of AMPK in mPFC inhibitory neurons underlies the anxiolytic effects of metformin, highlighting the potential of this primary antidiabetic drug as a therapeutic option for treating anxiety disorders.

Synaptic and circuit development of the primary sensory cortex

Animals, including humans, optimize their primary sensory cortex through the use of input signals, which allow them to adapt to the external environment and survive. The time window at the beginning of life in which external input signals are connected sensitively and strongly to neural circuit optimization is called the critical period. The critical period has attracted the attention of many neuroscientists due to the rapid activity-/experience-dependent circuit development that occurs, which is clearly differentiated from other developmental time periods and brain areas. This process involves various types of GABAergic inhibitory neurons, the extracellular matrix, neuromodulators, transcription factors, and neurodevelopmental factors. In this review, I discuss recent progress regarding the biological nature of the critical period that contribute to a better understanding of brain development.

The role of the leukemia inhibitory factor receptor in neuroprotective signaling

Several neurotropic cytokines relay their signaling through the leukemia inhibitory factor receptor. This 190kDa subunit couples with the 130kDa gp130 subunit to transduce intracellular signaling in neurons and oligodendrocytes that leads to expression of genes associated with neurosurvival. Moreover, activation of this receptor alters the phenotype of immune cells to an anti-inflammatory one. Although cytokines that activate the leukemia inhibitory factor receptor have been studied in the context of neurodegenerative disease, therapeutic targeting of the specific receptor subunit has been understudied in by comparison. This review examines the role of this receptor in the CNS and immune system, and its application in the treatment in stroke and other brain pathologies.