the neurons are put in their proper places, the last trimester of pregnancy is spent making neuronal connections in the brain. When the neuron reaches its niche after climbing like a caterpillar up the radial glial tree, it extends out growth cones. Like the head of a snake, the growth cone explores its environment for the best place to make a connection. Usually this is when it encounters another neuronal process. Both the axons and dendrites of neurons extend through growth cones. They have little hair-like structures on the end that help them move through the environment. The shaft of their extensions from the neuronal cell body extend incrementally as they reach out.
When they contact the next neuron, they form a connection and begin laying out the groundwork for the transmitters and receptors they use to communicate with one another.
The initial transmitter expression in the womb is a calcium-dependent process. Early in the embryonic stage, spontaneous calcium-dependentelectrical changes in neurons cause the transmitter to be expressed that will be used in the future by the neuron. If the calcium levels are tweaked, different types of transmitters can be expressed in the cells. This curious regulatory control by a calcium pulse draws parallels to the calcium wave of astrocytes as the control of information processing in the cortex.
While this occurs, areas near the ventricles begin dividing interneurons and oligodendrocytes. These cells provide functions to maintain the previously developed neuron—the interneurons inhibit other neurons and oligodenrocytes wrap fatty tissue around axons so they can better conduct electricity.
At this stage, deep brain structures nominally understood to be the seat of unconscious activity are formed. The limbic system and the basal ganglia become solidified. The basal ganglia are responsible for motor neuronal efficiency and are disrupted in Parkinson’s disease. The limbic system deals with our basic subconscious desires such as food and sex. Both are covered by the cortex, like a baby in a folded blanket.
After the neuronal framework is established, avenues and highways traversing the bulb behind our eyes, mouth, nose, and between our ears, extending to our limbs through our tail-like spine, are ready to be populated with our mind. Astrocytes begin to grow and fill niches near their support neurons, in places where they have easy access to sensory information to influence their calcium wave, places to experience the beauty of life, think about it, and transmit ideas into action through long-distance, quick communication down neuronal lines. Astrocytes are our mind. As they are about to peak, we slip out into the world, fully equipped to experience life as a human being.
Astrocyte proliferation coincides with birth. In rodents, which have a gestation period of three weeks, the peak of neuronal formation occurs at two weeks during the embryonic stage. Then astrocytes peak at birth or two days postnatally. A second wave of oligodendrocytes peak after birth. In humans, the timeframe follows the same course. As we are born, astrocytes become the houses next to the neuronal roads.
After the astrocyte explosion at birth, radial glia also stop dividing and turn into astrocytes themselves. Their long processes, now extending to the outer regions of a fully layered cortex, shrink back to the ventricles and assume an astrocytic morphology, like a man on stilts coming downto the ground and taking off his clown makeup. There astrocytes reside next to the ventricles as we enter adulthood. They are able to divide and create new cells throughout our lifespan.
Astrocytes are the basis for life in the brain. They self-replicate, are promiscuous, spit out progeny, and give us the ability to attempt to make sense of our world.
After the astrocytes have been placed next to their neuronal roads, synaptogenesis occurs. Synaptic connections have already been made. However, for proper communication,
When they contact the next neuron, they form a connection and begin laying out the groundwork for the transmitters and receptors they use to communicate with one another.
The initial transmitter expression in the womb is a calcium-dependent process. Early in the embryonic stage, spontaneous calcium-dependentelectrical changes in neurons cause the transmitter to be expressed that will be used in the future by the neuron. If the calcium levels are tweaked, different types of transmitters can be expressed in the cells. This curious regulatory control by a calcium pulse draws parallels to the calcium wave of astrocytes as the control of information processing in the cortex.
While this occurs, areas near the ventricles begin dividing interneurons and oligodendrocytes. These cells provide functions to maintain the previously developed neuron—the interneurons inhibit other neurons and oligodenrocytes wrap fatty tissue around axons so they can better conduct electricity.
At this stage, deep brain structures nominally understood to be the seat of unconscious activity are formed. The limbic system and the basal ganglia become solidified. The basal ganglia are responsible for motor neuronal efficiency and are disrupted in Parkinson’s disease. The limbic system deals with our basic subconscious desires such as food and sex. Both are covered by the cortex, like a baby in a folded blanket.
After the neuronal framework is established, avenues and highways traversing the bulb behind our eyes, mouth, nose, and between our ears, extending to our limbs through our tail-like spine, are ready to be populated with our mind. Astrocytes begin to grow and fill niches near their support neurons, in places where they have easy access to sensory information to influence their calcium wave, places to experience the beauty of life, think about it, and transmit ideas into action through long-distance, quick communication down neuronal lines. Astrocytes are our mind. As they are about to peak, we slip out into the world, fully equipped to experience life as a human being.
Astrocyte proliferation coincides with birth. In rodents, which have a gestation period of three weeks, the peak of neuronal formation occurs at two weeks during the embryonic stage. Then astrocytes peak at birth or two days postnatally. A second wave of oligodendrocytes peak after birth. In humans, the timeframe follows the same course. As we are born, astrocytes become the houses next to the neuronal roads.
After the astrocyte explosion at birth, radial glia also stop dividing and turn into astrocytes themselves. Their long processes, now extending to the outer regions of a fully layered cortex, shrink back to the ventricles and assume an astrocytic morphology, like a man on stilts coming downto the ground and taking off his clown makeup. There astrocytes reside next to the ventricles as we enter adulthood. They are able to divide and create new cells throughout our lifespan.
Astrocytes are the basis for life in the brain. They self-replicate, are promiscuous, spit out progeny, and give us the ability to attempt to make sense of our world.
After the astrocytes have been placed next to their neuronal roads, synaptogenesis occurs. Synaptic connections have already been made. However, for proper communication,
Similar Books
