Image: Opus Design. Neurons are the most fundamental unit of the nervous system, and yet, researchers are just beginning to understand how they perform the complex computations that underlie our behavior.
Some of these axons can be very long and most of them are very short. The electrical signal that runs along the axon is based on ion movement. Myelin is a fatty layer formed, in the vertebrate central nervous system, by concentric wrapping of oligodendrocyte cell processes around axons.
Neurons in the peripheral nervous system are also myelinated, but the cells responsible for myelination are Schwann cells, rather than oligodendrocytes. Adjacent sections of axon in a given neuron are each surrounded by a distinct myelin sheath. Myelin seems to be critical to healthy functioning of the nervous system; in fact, disruptions in the myelin sheath have been linked to a variety of disorders.
The blood—brain barrier is a layer of cells keeping the brain safe from pathogens, toxins, and other molecules circulating in the blood. It prevents invaders from entering the brain. However, oxytocin and vasopressin are also released from the dendrites of the neurons, directly into the brain. Scientists have discovered that the release of neuropeptides from dendrites into the brain and from axons terminals into the blood can happen independently. Release of vasopressin and oxytocin from the axon terminals is controlled by action potentials, similar to the neurotransmitter release triggered in all other neurons.
However, some chemical signals in the brain can stimulate neuropeptide release from the dendrites without triggering action potentials. Producing release in these different ways allows neuropeptide effects in the body and the brain to be regulated separately. This makes sure that the newborn receives all that is urgently needed: food and love Figure 3 [ 2 ].
Release of neuropeptides by the dendrites of neurons is very similar to the release of hormones elsewhere in your body.
Hormones are the chemical messengers released by glands and transported by the blood to distant target cells. So, hormones can stimulate cells that are located far away from the glands where they are produced. There are many different hormones, and they have lots of different functions in the body. Some of the behavior disorders hardest to treat, for which new therapies are urgently needed, affect behaviors in which vasopressin and oxytocin are involved [ 3 ].
But oxytocin is also important for the child to develop and maintain complex interactions with others. Some children with autism often have difficulties in understanding and responding to those interactions, and scientists are trying oxytocin as a potential treatment if you want to learn more about this, read the article written by Daniel Quintana and Gail Alvares in the Frontiers for Young Minds online library [ 4 ].
Other examples include disorders associated with stress and anxiety, disorders of eating, disorders of substance misuse including alcohol misuse , and disorders of sexual behavior. These are major health problems with a considerable impact on humans. By better understanding how brain cells and neuropeptides interact, we may find ways to control some of these disorders and improve the quality of our lives.
It is connected to the hypothalamus. It secretes hormones regulating many different bodily activities. During this time, your body is loaded with hormones that tell it that it is time to start changing. They might act in a way that seems unusual, and it can be hard to understand why they are acting that way. The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
I would like to thank my friends and colleagues at work who commented on the manuscript, especially my friends David and Gareth who made sure that I used the right words understandable for kids. Multiple signalling modalities mediated by dendritic exocytosis of oxytocin and vasopressin. B Biol. Synapse — The junction between the axon of one neuron and the dendrite of another, through which the two neurons communicate. QBI newsletters Subscribe. Help QBI research Give now. Skip to menu Skip to content Skip to footer.
Site search Search. Site search Search Menu. Action potentials and synapses. Home The Brain Brain functions. At the junction between two neurons synapse , an action potential causes neuron A to release a chemical neurotransmitter. The neurotransmitter can either help excite or hinder inhibit neuron B from firing its own action potential. In an intact brain, the balance of hundreds of excitatory and inhibitory inputs to a neuron determines whether an action potential will result.
Action potentials and synapses Adult neurogenesis What is neurogenesis? What is synaptic plasticity? Studying synaptic plasticity and learning How do neurons work?
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