The Inbox of a Neuron
These irregular rope-like structures are four individual dendrites. Dendrites are structures that neurons use to receive incoming signals from other cells. The protrusions you see coming off the trunks of the dendrites are called dendritic spines and are where most of the incoming cell-to-cell communication happens.
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DownloadThe Inbox of a Neuron
These irregular rope-like structures are four individual dendrites. Dendrites are structures that neurons use to receive incoming signals from other cells. The protrusions you see coming off the trunks of the dendrites are called dendritic spines and are where most of the incoming cell-to-cell communication happens.
What am I looking at?
Here we see four individual dendrites with dendritic spines (1) extending from the main dendrite (2). The dendrites were colored to distinguish them from each other.
Biology in the Background
A typical neuron is composed of three main structures: the cell body, axon, and dendrites. The cell body is where most of the cellular organelles are located, including the nucleus, which contains the majority of the cell’s DNA. It is the central hub and does most of the cell’s information processing. Axons are typically long projections that extend from the cell body and send outgoing signals to other neurons. Dendrites are shorter branched projections that extend from the cell and receive incoming signals from other cells.
Most dendrites form small protrusions extending from the main dendrite called spines. These spines can serve many functions. One of their main responsibilities is to form synapses with incoming processes from other neurons (most of the time with another cell’s axon). Synapses are where most cell-to-cell communication happens with one cell sending a signal to the other at a synapse. These spines are where the dendrites receive messages from other cells, which are then relayed in the form of a traveling wave of electrical charge to the cell body, where most of the information integration and processing happens.
This image was created by researchers studying the effect of sleep on synaptic connections. They were interested in learning how these connections change during sleep to keep the brain healthy. They discovered that connections between neurons were stronger during wake time and weaker during sleep. They hypothesize that this is to give neurons a break during sleep to prevent them from getting overwhelmed by a constant flow of information.
Dendritic spines in mice (seen here) can grow up to 2.5 micrometers long, roughly 30 times smaller than the width of a human hair. Spines are larger in humans, growing up to 4 micrometers in length, about 19 times smaller than the width of a human hair.
Technique
This image was reconstructed using information gathered by electron microscopy.
National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, and National Institute of General Medical Sciences, NIH