לוח שנה משולב

The brain consists of a mosaic of distinct cell-types with unique activity-regulated gene programs that can drive long-lasting changes in the function and structure of developing and matured neural circuits. However, the molecular mechanisms in specific neuronal subtypes underlying these cellular/circuit changes remain poorly understood and techniques for studying these molecular mechanisms in specific cell populations are still lacking. Genomic enhancers are thought to modulate specific sets of synapses by regulating experience-induced and cell-type specific transcription of genes that promote neural circuit plasticity. Nevertheless, this idea remains untested. Thus, here I set out to investigate the genomic mechanisms that control the experience-induced transcription of the Insulin-like growth factor 1 (Igf1) in disinhibitory VIP interneurons (INs) in the adult visual cortex and the cellular and circuit functions they underly. I found two cell-type specific sensory-induced enhancers that selectively drive sensory-induced Igf1 transcription. These enhancers homeostatically control the ratio between excitation and inhibition (E/I-ratio), thereby restricting the activity of VIP INs and preserving the response properties to visual stimuli.

Abstract:
Plants synthesize an amazing diversity of volatile organic compounds (VOCs) that facilitate interactions with their environment, ranging from attracting pollinators and seed dispersers to protecting themselves from pathogens, parasites, and herbivores. Plants are also targets of released compounds as a part of plant-plant communication, as well as plant-insect and plant-microbe interactions. They are constantly exposed to atmospheric VOCs and can differentiate and respond to specific cues. Therefore, VOC release out of the cell and perception of emitted volatiles are an essential part of information exchange. The presented results will cover different aspects of VOC biosynthesis and emission including the involvement of heterodimeric enzymes in VOC biosynthesis, the role of transporters, lipid transfer proteins and lipid droplets in VOC trafficking out o! f the cell, and the function of the cuticle as an integral member of the overall VOC biosynthetic network. This presentation will also discuss the latest knowledge about VOC perception: from an inter-organ aerial transport of VOCs via natural fumigation and hormone-like function for terpenoid compounds to a signaling pathway(s) involved.

Magnetism is one of the largest, most fundamental, and technologically most relevant fields of condensed-matter physics. Traditionally, two elementary magnetic phases have been distinguished - ferromagnetism and antiferromagnetism. The spin polarization in the electronic band structure reflecting the magnetization in ferromagnetic crystals underpins the broad range of time-reversal symmetry-breaking responses in this extensively explored and exploited type of magnets. By comparison, antiferromagnets have vanishing net magnetization. Recently, there have been observations of materials in which strong time-reversal symmetry-breaking responses and spin-polarization phenomena, typical of ferromagnets, are accompanied by antiparallel magnetic crystal order with vanishing net magnetization, typical of antiferromagnets [1]. A classification and description based on spin-symmetry principles offers a resolution of this apparent contradiction by establishing a third distinct elementary magnetic phase, dubbed altermagnetism [2]. We will start the talk with an overview of the still emerging unique phenomenology of this unconventional d-wave (or higher even-parity wave) magnetic phase, and of the wide array of altermagnetic materials. We will then show how altermagnetism can facilitate a development of ultra-fast and low-dissipation spintronic information technologies, and can have impact on a range of

other modern areas of condensed matter physics and nanoelectronics.

References
[1] L. Šmejkal, A. H. MacDonald, J. Sinova, S. Nakatsuji, T. Jungwirth, Nature Reviews Mater. 7, 482 (2022).
[2] L. Šmejkal, J. Sinova & T. Jungwirth, Phys. Rev. X (Perspective) 12, 040501 (2022).