Polarity and intracellular compartmentalization of Drosophila neurons - Discover Neuroscience

Background Proper neuronal function depends on forming three primary subcellular compartments: axons, dendrites, and soma. Each compartment has a specialized function (the axon to send information, dendrites to receive information, and the soma is where most cellular components are produced). In mammalian neurons, each primary compartment has distinctive molecular and morphological features, as well as smaller domains, such as the axon initial segment, that have more specialized functions. How neuronal subcellular compartments are established and maintained is not well understood. Genetic studies in Drosophila have provided insight into other areas of neurobiology, but it is not known whether flies are a good system in which to study neuronal polarity as a comprehensive analysis of Drosophila neuronal subcellular organization has not been performed. Results Here we use new and previously characterized markers to examine Drosophila neuronal compartments. We find that: axons and dendrites can accumulate different microtubule-binding proteins; protein synthesis machinery is concentrated in the cell body; pre- and post-synaptic sites localize to distinct regions of the neuron; and specializations similar to the initial segment are present. In addition, we track EB1-GFP dynamics and determine microtubules in axons and dendrites have opposite polarity. Conclusion We conclude that Drosophila will be a powerful system to study the establishment and maintenance of neuronal compartments.

(BBSRC NWD) Developing a vCLEM pipeline for high-resolution analysis of neurons of the Drosophila brain at University of Liverpool on FindAPhD.com

PhD Project - (BBSRC NWD) Developing a vCLEM pipeline for high-resolution analysis of neurons of the Drosophila brain at University of Liverpool, listed on FindAPhD.com

Axons compensate for biophysical constraints of variable size to uniformize their action potentials

Why is the repolarization phase of the neuronal actional potential so uniform despite the variability in axon diameters? This study shows that increased Kv1 potassium currents in smaller axonal structures compensate for their biophysical constraints resulting in size-independent synaptic trigger signals along the entire axon.

Fueling nerve cell function and plasticity

How mitochondria control tissue rejuvenation and synaptic plasticity in the adult mouse brain

Identification of the growth cone as a probe and driver of neuronal migration in the injured brain - Nature Communications

Structure and functions of the tip of migratory neurons remain elusive. Here, the authors show that the PTPσ-expressing growth cone senses extracellular matrix changes and drives neuronal migration in the injured brain, leading to the functional recovery.

Short-term Hebbian learning can implement transformer-like attention

Author summary Many of the most impressive recent advances in machine learning, from generating images from text to human-like chatbots, are based on a neural network architecture known as the transformer. Transformers are built from so-called attention layers which perform large numbers of comparisons between the vector outputs of the previous layers, allowing information to flow through the network in a more dynamic way than previous designs. This large number of comparisons is computationally expensive and has no known analogue in the brain. Here, we show that a variation on a learning mechanism familiar in neuroscience, Hebbian learning, can implement a transformer-like attention computation if the synaptic weight changes are large and rapidly induced. We call our method the match-and-control principle and it proposes that when presynaptic and postsynaptic spike trains match up, small groups of synapses can be transiently potentiated allowing a few presynaptic axons to control the activity of a neuron. To demonstrate the principle, we build a model of a pyramidal neuron and use it to illustrate the power and limitations of the idea.

Oligodendrocyte - Wikipedia