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14

Regarding your question about losing synapses; yes, synapses are regularly lost in a process called Synaptic Pruning. From the Wikipedia article: A decrease in synapses is seen after adolescence reflecting synaptic pruning, and approximately 50% of neurons during development do not survive until adulthood. Pruning is influenced by environmental factors ...


12

A synapse from a neuron unto itself is called an Autapse. Not a whole lot is known about them. Tamas et al. (1) give a summary: Van der Loos and Glaser (1972)proposed the word “autapse” to describe a transmitter release site made by the axon of a neuron and its own somatodendritic domain. In addition to their original Golgi study in rabbit ...


10

Spine formation (spinogenesis) is almost certainly due to chemical, rather than electrical, signalling between neurons. Although there are exceptions (gap junctions, for one), most forms of inter-cellular communication are mediated by chemicals released by one cell and detected by another. You are right that the cues for synaptogenesis are probably localized ...


10

Dendritic spines are thought to grow and recede under LTP and LTD, respectively. See (Bosch and Hayoshi 2011) for a review. From there, much of the synaptogenesis occurs due to surface molecules present both on the dendrite and the presynaptic axon in the growth cone. Localization and guidance are achieved through gradients of growth factors in the ...


8

An inhibitory synapse works just like a stimulatory one! When a presynaptic neuron fires it will release a neurotransmitter at its terminal(s). This neurotransmitter can be excitatory or inhibitory, the main excitatory one being glutamate and the main inhibitory one GABA.* GABA and Glu are far from being the only neurotransmitters in the brain, they're ...


4

You are looking for a review on vesicle cargoing along the cytoskeleton. This open access article is the most recent I found on the subject. From the abstract: How synaptic cargos achieve specificity, directionality and timing of transport is a developing area of investigation. Recent studies demonstrate that the docking of motors to their cargos is a ...


3

From your comment to nico's good answer, it seems that your question is really about how synaptic potentials propagate through dendrites. Canonically, synaptic potentials travel passively along membranes and is described by cable theory. The cable equation describes how the voltage will change over time and space along a cable. The theory was originally ...


3

There isn't enough research out there to explain the role of autapses however having read a selection of the latest research I can perhaps explain some of the proposed theory. Autapses may self inhibit or self excite. In the latter, one of their roles is thought to be to make a rhythmic action potential. This allows the brain to have an action potential ...


3

You are correct that cocaine "fills the tunnel" (the pharmacology terminology is that it "blocks the transporter"). But it is not an autoreceptor, so the reuptake transporter does not send a stop signal, it just removed neurotransmitter from the cleft. But once you've blocked it with cocaine, neurotransmitter is not being removed from the cleft so it has a ...


2

Having just read this article (http://www.ncbi.nlm.nih.gov/books/NBK11164/) there are several advantages/functional reasons that seem apparent and important in having electrical synapses with gap junctions compared to just a very long neuron. a) signals in electrical synapse can be bidirectional. b) electrical synapse synchronize electrical activity among ...


1

Edward George Gray went by the first name of George, which isn't evident from his initials (he was born Edward George), but I happened to stumble upon the Wikipedia article below. From there, I found his obituary. From his obituary: GEORGE GRAY was a pioneer in the study of brain ultrastructure. He was Professor of Cytology in the anatomy department at ...



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