Search results
Results from the WOW.Com Content Network
Interkinetic nuclear migration is a feature of developing neuroepithelia and is characterized by the periodic movement of the cell’s nucleus with the progression of the cell cycle. Developing neuroepithelia are tissues composed of neural progenitor cells, each spanning the entire thickness of the epithelium from the ventricular surface to the ...
At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis.
[20] [21] In fact, gap junctions facilitate the direct flow of electrical current without the need for neurotransmitters, as well as small molecules like calcium. [22] Thus, the main advantage of an electrical synapse is the rapid transfer of signals from one cell to the next. [20]
Each gap junction (sometimes called a nexus) contains numerous gap junction channels that cross the plasma membranes of both cells. [11] With a lumen diameter of about 1.2 to 2.0 nm, [2] [12] the pore of a gap junction channel is wide enough to allow ions and even medium-size molecules like signaling molecules to flow from one cell to the next, [2] [13] thereby connecting the two cells' cytoplasm.
Neurons vary in shape and size and can be classified by their morphology and function. [20] The anatomist Camillo Golgi grouped neurons into two types; type I with long axons used to move signals over long distances and type II with short axons, which can often be confused with dendrites. Type I cells can be further classified by the location ...
The newly generated neurons migrate to different parts of the developing brain to self-organize into different brain structures. Once the neurons have reached their regional positions, they extend axons and dendrites, which allow them to communicate with other neurons via synapses.
In both images neurons are stained with a somatodendritic marker, microtubule associated protein (red). In the right image, synaptic vesicles are stained in green (yellow where the green and red overlap). Scale bar = 25 μm. [3] Synaptic vesicles are relatively simple because only a limited number of proteins fit into a sphere of 40 nm diameter.
Axonal transport, also called axoplasmic transport or axoplasmic flow, is a cellular process responsible for movement of mitochondria, lipids, synaptic vesicles, proteins, and other organelles to and from a neuron's cell body, through the cytoplasm of its axon called the axoplasm. [1]