Science: Scientists have found the key hub for negative emotions - the mid-stitch nucleus.

Click the blue word to pay attention to our animals. In order to survive, we must predict the danger and avoid it in the shortest time.this process requires not only assessment and prediction of aversion stimuli by nucleus stiff (LHB) and ventromedial tegmental area (MVTA), but also hippocampal reawakening these aversion memories.the raphe area (MRR) in the lower part of the brainstem may play a key role in the two processes.MRR neurons express 5-hydroxytryptamine (5-HT) and vesicular glutamate transporter 3 (VGLUT3). However, it is not clear how MRR neurons connect these two processes and then play their corresponding functions.November 29, 2019, G á bor, Department of neural network and molecular science, Institute of experimental medicine, Hungarian Academy of Sciences Nyiri research team published an article on science, revealing that raphe nucleus plays a key pivotal role in regulating negative emotions, integrating negative emotional information related to LHB and MVTA and memory information related to hippocampus, which may participate in the pathogenesis of mental diseases such as anxiety and depression.researchers injected CRE enzyme dependent AAV virus into MRR of VGLUT2 CRE mice, and found that about 20% of neurons were VGLUT2 positive neurons, mainly located in the middle of MRR.these anterograde viruses are mainly expressed in LHB and MVTA (other parts also have local projections), which indicates that the VGLUT2 positive neurons of MRR project to LHB and MVTA.further using fluorescence technology, we found that there were 13% 5-HT neurons, 60% GABAergic neurons and 20% VGLUT2 positive neurons in MRR.similarly, in VGAT CRE, VGLUT3 CRE and TPH – CRE mice, there was no projection pattern similar to that of VGLUT2 positive neurons.this further indicates that the VGLUT2 positive neurons have a specific type in the projection, and this anatomical specificity provides the possibility of functional connection.LHB glutamatergic neurons can dominate MVTA dopaminergic neurons, thus regulating negative reward prediction and aversion behavior.the researchers injected CRE enzyme dependent AAV expressing red fluorescence into LHB, and injected green fluorescent AAV virus into MRR brain area. Red and green fluorescence could be detected in MVTA brain area at the same time, which indicated that they could project to MVTA brain area.in addition, there were at least 39% fibers in LHB brain area which dominated VGLUT2 positive neurons in MRR brain area.further use of retrograde tracing virus found that the brain regions associated with negative emotions, such as dorsal raphe (DR), lateral hypothalamus (LH), periaqueductal gray matter and zona adventitia, were the upstream projection areas of VGLUT2 positive neurons in MRR.these results indicate that there are structural connections between VGLUT2 positive neurons in MRR and several brain regions related to negative emotions.scanning electron microscopy revealed that the VGLUT2 positive neurons in the MRR brain area projected to the nucleus ossificans and formed multiple synapses with the neurons in the nucleus ossificans. Specifically, each projection fiber could form an average of 2.1 synapses.these synapses contain GluN2A and glun1 subunits, which indicates that the synapses formed contain NMDA receptors.What's more surprising is that glial cells surround these synapses.(what is this for? Protect or hijack What is the function of these synapses? Light activated glutamatergic excitatory currents and cluster discharges of neurons in the nucleus ossificans were induced by light activation of the fibers projecting from GLUT2 positive neurons to the nucleus.these currents have strong short-term inhibitory effects and can be blocked by AMPA receptor and NMDA receptor antagonists.the researchers further explored how MRR is involved in the regulation of negative emotions? Using real-time and conditional location aversion experiments, they found that after activating the VGLUT2 positive neurons in the MRR brain area, the mice showed obvious position aversion behavior, that is, they tended to stay on the side without stimulation.in addition, the researchers used chemical genetic techniques to chronically activate the VGLUT2 positive neurons in the MRR brain area, which increased the aggressive behavior of mice, and also showed a depression like behavior phenotype (the behavior of mice drinking sugar water decreased, which is the manifestation of the loss of pleasure, the core symptom of depression).these results suggest that the VGLUT2 positive neurons in the MRR brain region are indeed involved in the regulation of negative emotions or behaviors.previous studies have shown that rapid and effective processing of negative experiences requires induced memory acquisition, which requires the involvement of the parabrachial nucleus hippocampus system.virus tracing experiments showed that MRR projection fibers were also widely expressed in the parabrachial nucleus, which formed functional synapses with parvalbumin positive inhibitory neurons in the parabrachial nucleus.what is more surprising is that these projection fibers partially coincide with the fibers projecting from the parabrachial nucleus to the hippocampus.this indicates that VGLUT2 neurons in MRR can directly control the fibers projecting from hippocampus to parabrachial nucleus.after further photoinhibition of VGLUT2 neurons in MRR brain area, mice did not show obvious rigidity during fear memory training, which indicated that fear learning and memory were impaired.furthermore, it was found that during the memory retrieval period, mice still could not extract the fear related memory as the normal mice, which indicated that memory consolidation might be impaired.in conclusion, in this study, we used a variety of virus tracing techniques combined with chemical and optogenetic techniques to discover the undetected functions of MRR brain regions as the key central control of negative emotions.more specifically, the activation of VGLUT2 neurons in this brain region resulted in a variety of negative emotional behaviors, such as positional aversion, increased aggressiveness, and depression like behavior. After inhibition of these neurons, fear learning and memory consolidation were impaired.PS: the color and style of the pictures in this article are so beautiful that the editor can't help but put a few more.< br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / < br / references; references; andrá s szos, NYI, krisztti á n, zich ó, Albert M. Barth, Robert M. Barth, Roland Roland T, G, G ü n, 2015), DOI: 10.1002 / cne.2362366, 1094 (2019) 1094 (2019) 1094 62; PMID: 25099741g Buzs á Ki, e. I. Moser, memory, navigation and theta rhythm in the hippocampal Oriental system. NAT. Neurosci. 16, 130 – 138 (2013). Doi: 10.1038/nn.3304; PMID: 23354386, the cover pictures and article pictures are all from the related articles of network history; Science sub: may subvert cognition aging gut flora promote nerve regeneration? Can pet and dreamd really manipulate neural circuits in humans in the future? Review the progress made by domestic scientists in the field of neuroscience in 2019. Special thanks: the communication group 1 autism communication group 2 depression communication group 3 animal model communication group 4 PD communication group 5 neuroscience technology communication group 6 neuroscience clinician communication group 7 literature sharing discussion communication group 8 ad communication group 9 anxiety disorder communication group 10 learning and memory communication group Concerned about the reply number 1 WeChat public, pull you into the group concerned about the official account reprint, contribution, cooperation and other related matters, please add WeChat: Neuroscience-week long by two-dimensional code attention, if we feel good, we can praise or see yo.