Biphasic Cholinergic Modulation of Reverberatory Activity in Neuronal Networks

Cholinergic signaling to CA1 astrocytes controls fear extinction

Fear extinction is an evolutionarily conserved biological process that allows an organism to better re-adapt; its deficits can lead to psychiatric disorders. Fear extinction is considered to rely mostly on neuronal function. However, whether and how astrocytes contribute to fear extinction is largely unknown. Here, we show that hippocampal CA1 astrocytes exhibit de novo Ca2+ dynamics during fear extinction. Inhibition of these astrocytic Ca2+ dynamics impairs, while their activation facilitates, fear extinction. In this regulation of fear extinction, the posterior basal forebrain (pBF) cholinergic input to hippocampus drives CA1 astrocytic Ca2+ dynamics through the activation of α4 and α7 subunits of nicotinic acetylcholine receptors. Clinically used acetylcholinesterase inhibitor donepezil increases CA1 astrocytic Ca2+ dynamics and facilitates fear extinction. Thus, our findings demonstrate a previously unrecognized and crucial pathway from pBF cholinergic neurons to CA1 astrocytes that governs natural fear extinction. This neuron-glia signaling pathway may constitute a promising target for treatment of fear- and anxiety-related disorders.

Potentiation of visualized exosomal miR-1306-3p from primary sensory neurons contributes to chronic visceral pain via spinal P2X3 receptors

ABSTRACT

Exosomes served as "communicators" to exchange information among different cells in the nervous system. Our previous study demonstrated that the enhanced spinal synaptic transmission contributed to chronic visceral pain in irritable bowel syndrome. However, the underlying mechanism of primary sensory neuron (PSN)-derived exosomes on spinal transmission remains unclear. In this study, an exosome visualization method was established to specifically track exosomes derived from PSNs in CD63-GFPf/+ (green fluorescent protein) mice. Neonatal maternal deprivation (NMD) was adopted to induce chronic visceral pain in CD63-GFPf/+ male mice. The exosome visualization technology demonstrated that NMD increased visible PSN-derived exosomes in the spinal dorsal horn, enhanced spinal synaptic transmission, and led to visceral pain in CD63-GFPf/+ male mice. The PSN-derived exosomal miR-1306-3p sorted from spinal dorsal horn activated P2X3R, enhanced spinal synaptic transmission, and led to visceral pain in NMD mice. Moreover, upregulation of Rab27a in dorsal root ganglia mediated the increased release of PSN-derived exosomes, and intrathecal injection of siR-Rab27a reduced visible PSN-derived exosomes in spinal cord, suppressed spinal synaptic transmission, and alleviated visceral pain in NMD mice. This and future studies would reveal the detailed mechanisms of PSN-derived exosomes and provide a potential target for clinical treatment of chronic visceral pain in patients with irritable bowel syndrome.

Low-Power Perovskite Neuromorphic Synapse with Enhanced Photon Efficiency for Directional Motion Perception

The advancement of artificial intelligent vision systems heavily relies on the development of fast and accurate optical imaging detection, identification, and tracking. Framed by restricted response speeds and low computational efficiency, traditional optoelectronic information devices are facing challenges in real-time optical imaging tasks and their ability to efficiently process complex visual data. To address the limitations of current optoelectronic information devices, this study introduces a novel photomemristor utilizing halide perovskite thin films. The fabrication process involves adjusting the iodide proportion to enhance the quality of the halide perovskite films and minimize the dark current. The photomemristor exhibits a high external quantum efficiency of over 85%, which leads to a low energy consumption of 0.6 nJ. The spike timing-dependent plasticity characteristics of the device are leveraged to construct a spiking neural network and achieve a 99.1% accuracy rate of directional perception for moving objects. The notable results offer a promising hardware solution for efficient optoneuromorphic and edge computing applications.