What happens to the electric waves in our brain when we generate a linguistic expression without emitting any sound?
Language can also be present in the absence of sound, when we read or when we use words while thinking.
"The very fact that the majority of human communication takes place via waves may not be a casual fact; after all, waves constitute the purest system of communication since they transfer information from one entity to the other without changing the structure or the composition of the two entities. They travel through us and leave us intact, but they allow us to interpret the message borne by their momentary vibrations, provided that we have the key to decode it. It is not at all accidental that the term information is derived from the Latin root forma (shape): To inform is to share a shape.
In his “Philosophical Investigations,” Ludwig Wittgenstein asked: “Is it conceivable that people should never speak an audible language, but should nevertheless talk to themselves inwardly, in the imagination?” "
Electrodes on the brain have been used to translate brainwaves into words spoken by a computer – which could be useful in the future to help people who have lost the ability to speak.
When you speak, your brain sends signals from the motor cortex to the muscles in your jaw, lips and larynx to coordinate their movement and produce a sound.
“The brain translates the thoughts of what you want to say into movements of the vocal tract, and that’s what we’re trying to decode,” says Edward Chang at the University of California San Francisco (UCSF). He and his colleagues created a two-step process to decode those thoughts using an array of electrodes surgically placed onto the part of the brain that controls movement, and a computer simulation of a vocal tract to reproduce the sounds of speech.
Neural stem cells have the potential to generate all neural cell types. They differentiate into neuronal progenitor cells, which give rise to neuron, or glial progenitors, which give rise to glial cells. (Image Credit: NCD Project / CC BY-SA 3.0 via Commons)
Neurogenesis is the process by which new neurons are formed in the brain. Neurogenesis is crucial when an embryo is developing but also continues in certain brain regions after birth and throughout our lifespan.
The mature brain has many specialised areas of function, and neurons that differ in structure and connections. The hippocampus, for example, which is a brain region that plays an important role in memory and spatial navigation, alone has at least 27 different types of neurons.
The incredible diversity of neurons in the brain results from regulated neurogenesis during embryonic development. During the process, neural stem cells differentiate—that is, they become any one of a number of specialised cell types—at specific times and regions in the brain.
Researchers think neurogenesis helps the brain distinguish between two very similar objects or events, a phenomenon called pattern separation.
According to one hypothesis, new neurons’ excitability in response to novel objects diminishes the response of established neurons in the dentate gyrus to incoming stimuli, helping to create a separate circuit for the new, but similar, memory.
There are different types of neurons being born in the brain throughout life. The problem is their very small cells, they’re very scattered, and they're very few of them. So they’re very tough to see and very tough to study.
Do new neurons appear anywhere else in the brain?
"Many, though not all, neuroscientists agree that there’s ongoing neurogenesis in the hippocampus of most mammals, including humans. In rodents and many other animals, neurogenesis has also been observed in the olfactory bulbs.
Whether newly generated neurons show up anywhere else in the brain is more controversial.
There had been hints of new neurons showing up in the striatum of primates in the early 2000s. In 2005, Heather Cameron of the National Institute of Mental Health and colleagues corroborated those findings, showing evidence of newly made neurons in the rat neocortex, a region of the brain involved in spatial reasoning, language, movement, and cognition, and in the striatum, a region of the brain involved in planning movements and reacting to rewards, as well as self-control and flexible thinking (J Cell Biol, 168:415–27).
Nearly a decade later, using nuclear-bomb-test-derived carbon-14 isotopes to identify when nerve cells were born, Jonas Frisén of the Karolinska Institute in Stockholm and colleagues examined the brains of postmortem adult humans and confirmed that new neurons existed in the striatum."
What happens to memories as days, weeks and years go by has long been a fundamental question in neuroscience and psychology.
For decades, researchers have attempted to identify the brain regions in which memory is formed and to follow its changes across time.
The theory of systems consolidation of memory (SCM) suggests that changes in circuitry and brain networks are required for the maintenance of memory with time.
Various mechanisms by which such changes may take place have been hypothesized.
Recently, several studies have provided insight into the brain networks driving SCM through the characterization of memory engram cells, their biochemical and physiological changes and the circuits in which they operate.
Crucial to this process of linking engram cells is the ability of neurons to forge new circuit connections, via processes known as "synaptic plasticity" and "dendritic spine formation."
Importantly, experiments show that the memory initially stored across an engram complex can be retrieved by its reactivation but may also persist "silently" even when memories cannot be naturally recalled, for instance in mouse models used to study memory disorders such as early-stage Alzheimer's disease.
The hippocampus, a structure located deep within the brain, has long been seen as a hub for memory. The hippocampus helps “glue” parts of the memory together (the “where” with the “when”) by ensuring that neurons fire together. This is often referred to as “neural synchronisation”. When the neurons that code for the “where” synchronise with the neurons that code for the “when”, these details become associated through a phenomenon known as “Hebbian learning”.
But the hippocampus is simply too small to store every little detail of memory. This has lead researchers to theorise that the hippocampus calls upon the neocortex – a region which processes complex sensory details such as sound and sight – to help fill in the details of a memory.
The neocortex does this by doing the exact opposite of what the hippocampus does – it ensures that neurons do not fire together.
This is often referred to as “neural desynchronisation”. Imagine asking an audience of 100 people for their names. If they synchronise their response (that is, they all scream out at the same time), you’re probably not going to understand anything.
But if they desynchronise their response (that is, they take turns speaking their names), you’re probably going to gather a lot more information from them. The same is true for neocortical neurons – if they synchronise, they struggle to get their message across, but if they desynchronise, the information comes across easily.
The new research questions the seminal work done by French
neuroscientist Louis Lapicque, whose theory on how neurons operate was
first proposed in 1907. He was nominated for a Nobel Prize for his
research. Despite the new findings, it remains one of the most popular
models of how our brains function. Physicist Ido Kanter – whose research spans the gamut from complexity theory and random numbers to chaotic lasers – led the new study.
"We reached this conclusion using a new experimental setup, but in
principle these results could have been discovered using technology that
has existed since the 1980s. The belief that has been rooted in the
scientific world for 100 years resulted in this delay of several
decades," With neural networks inspiring future computational
technology, identifying any new talents in brain cells could have some
rather interesting applications.
Behavioural evidence suggests that targeting just 20 neurons prompted animals to ‘see’ an image.
In new research, scientists used light to precisely activate cells in a
mouse's visual cortex, re-creating the brain activity involved in
seeing specific patterns.
That observation might help explain why
disordered states—hallucinations, unwanted thoughts, and harmful
actions—arise so readily in the brain. And single-neuron optogenetics
may someday point researchers toward highly targeted ways of stamping out these states and treating symptoms of brain diseases.
"Imagine every neuron in the brain like a key on the piano, You can literally choose which neurons to turn on."
“We don’t know how many cells it might take to trigger a more elaborate
thought, sensory experience, or emotion in a person,” says Karl
Deisseroth, a neuroscientist and psychiatrist at Stanford College in
Palo Alto, California, who led one of many new research, revealed
on-line this week in Science, “but it’s likely to be a surprisingly small number, given what we’re seeing in the mouse.” https://www.sciencemag.org http://fooshya.com/
Neurotransmitter is a chemical substance which is released at the end of a nerve fibre
by the arrival of a nerve impulse and, by diffusing across the synapse
or junction, effects the transfer of the impulse to another nerve fibre,
a muscle fibre, or some other structure.
Discovery of Neurotransmitters
In 1921, an Austrian scientist named Otto Loewi discovered the first neurotransmitter. In his experiment (which came to him in a dream), he used two frog hearts.
One
heart (heart #1) was still connected to the vagus nerve. Heart #1 was
placed in a chamber that was filled with saline. This chamber was
connected to a second chamber that contained heart #2. So, fluid from
chamber #1 was allowed to flow into chamber#2.
Electrical
stimulation of the vagus nerve (which was attached to heart #1) caused
heart #1 to slow down. Loewi also observed that after a delay, heart #2
also slowed down. From this experiment, Loewi hypothesized that
electrical stimulation of the vagus nerve released a chemical into the
fluid of chamber #1 that flowed into chamber #2. He called this chemical
“Vagusstoff“. We now know this chemical as the neurotransmitter called “acetylcholine“.
Neurotransmitters are often referred to as the body’s chemical
messengers. They are the molecules used by the nervous system to
transmit messages between neurons, or from neurons to muscles.
Communication between two neurons happens in the synaptic cleft (the small gap between the synapses of neurons). Here, electrical signals that have travelled along the axon
are briefly converted into chemical ones through the release of
neurotransmitters, causing a specific response in the receiving neuron.
A neurotransmitter influences a neuron in one of three ways: excitatory, inhibitory or modulatory.
An excitatory transmitter promotes the generation of an electrical signal called an action potential
in the receiving neuron, while an inhibitory transmitter prevents it.
Whether a neurotransmitter is excitatory or inhibitory depends on the
receptor it binds to.
Neuromodulators are a bit different, as they are not restricted to
the synaptic cleft between two neurons, and so can affect large numbers
of neurons at once. Neuromodulators therefore regulate populations of
neurons, while also operating over a slower time course than excitatory
and inhibitory transmitters.
Most neurotransmitters are either small amine molecules, amino acids,
or neuropeptides. There are about a dozen known small-molecule
neurotransmitters and more than 100 different neuropeptides, and
neuroscientists are still discovering more about these chemical
messengers. These chemicals and their interactions are involved in
countless functions of the nervous system as well as controlling bodily
functions.
Key neurotransmitters
Neurotransmitter Types
There are many types of chemicals that act as neurotransmitter substances. Below is a list of some of them.
1. Small Molecule Neurotransmitter Substances
Acetylcholine (ACh)
Dopamine (DA)
Norepinephrine (NE)
Serotonin (5-HT)
Histamine
Epinephrine
2.Amino Acids
Gamma-aminobutyric acid (GABA)
Aspartate
Glycine
Glutamate
3. Neuroactive Peptides – partial list
Bradykinin
beta-endorphin
bombesin
calcitonin
cholecystokinin
enkephalin
dynorphin
insulin
gastrin
substance P
neurotensin
glucagon
secretin
somatostatin
motilin
vasopressin
oxytocin
prolactin
thyrotropin
angiotensin II
sleep peptides
galanin
neuropeptide Y
thyrotropin-releasing hormone
gonadotropnin-releasing hormone
growth hormone-releasing hormone
luteinizing hormone
vasoactive intestinal peptide
4. Soluble Gases:
Nitric Oxide (NO)
Carbon Monoxide
The first neurotransmitter to be discovered was a small molecule called acetylcholine.
It plays a major role in the peripheral nervous system, where it is
released by motor neurons and neurons of the autonomic nervous system.
It also plays an important role in the central nervous system in
maintaining cognitive function. Damage to the cholinergic neurons of the
CNS is associated with Alzheimer disease.
Glutamate is the primary excitatory transmitter in
the central nervous system. Conversely, a major inhibitory transmitter
is its derivative γ-aminobutyric acid (GABA), while another inhibitory neurotransmitter is the amino acid called glycine, which is mainly found in the spinal cord.
Many neuromodulators, such as dopamine, are
monoamines. There are several dopamine pathways in the brain, and this
neurotransmitter is involved in many functions, including motor control,
reward and reinforcement, and motivation.
Noradrenaline (or norepinephrine) is another
monoamine, and is the primary neurotransmitter in the sympathetic
nervous system where it works on the activity of various organs in the
body to control blood pressure, heart rate, liver function and many
other functions.
Neurons that use serotonin (another monoamine)
project to various parts of the nervous system. As a result, serotonin
is involved in functions such as sleep, memory, appetite, mood and others. It is also produced in the gastrointestinal tract in response to food.
Histamine, the last of the major monoamines, plays a
role in metabolism, temperature control, regulating various hormones,
and controlling the sleep-wake cycle, amongst other functions.
Synthesis of Neurotransmitters
Acetylcholine
is found in both the central and peripheral nervous systems. Choline is
taken up by the neuron. When the enzyme called choline
acetyltransferase is present, choline combines with acetyl coenzyme A
(CoA) to produce acetylcholine.
Dopamine, norepinephrine and
epinephrine are a group of neurotransmitters called “catecholamines”.
Norepinephrine is also called “noradrenalin” and epinephrine is also
called “adrenalin”. Each of these neurotransmitters is produced in a
step-by-step fashion by a different enzyme.
Transport and Release of Neurotransmitters:
Neurotransmitters
are made in the cell body of the neuron and then transported down the
axon to the axon terminal. Molecules of neurotransmitters are stored in
small “packages” called vesicles (see the picture on the right).
Neurotransmitters are released from the axon terminal when their
vesicles “fuse” with the membrane of the axon terminal, spilling the
neurotransmitter into the synaptic cleft.
Unlike
other neurotransmitters, nitric oxide (NO) is not stored in synaptic
vesicles. Rather, NO is released soon after it is produced and diffuses
out of the neuron. NO then enters another cell where it activates
enzymes for the production of “second messengers”.
Receptor Binding
Neurotransmitters will bind only to specific receptors on the post-synaptic membrane that recognize them.
Inactivation of Neurotransmitters
The action of neurotransmitters can be stopped by four different mechanisms: 1. Diffusion: the neurotransmitter drifts away, out of the synaptic cleft where it can no longer act on a receptor.
2. Enzymatic degradation (deactivation):
a specific enzyme changes the structure of the neurotransmitter so it
is not recognized by the receptor. For example, acetyl-cholinesterase is
the enzyme that breaks acetylcholine into choline and acetate.
3. Glial cells: astrocytes remove neurotransmitters from the synaptic cleft.
4. Re-uptake:
the whole neurotransmitter molecule is taken back into the axon
terminal that released it. This is a common way the action of
norepinephrine, dopamine and serotonin is stopped…these
neurotransmitters are removed from the synaptic cleft so they cannot
bind to receptors. https://www.biochemden.com/neurotransmitters-neuropepptides/ https://qbi.uq.edu.au/brain/brain-physiology/what-are-neurotransmitters
Oxytocin is a hormone that acts on organs in the body (including the breast and uterus) and as a chemical messenger in the brain, controlling key aspects of the reproductive system, including childbirth and lactation, and aspects of human behaviour.
Oxytocin is a hormone and a neurotransmitter that is involved in childbirth and breast-feeding. It is also associated with empathy, trust, sexual activity, and relationship-building.
It is sometimes referred to as the "love hormone," because levels of oxytocin increase during hugging and orgasm. It may also have benefits as a treatment for a number of conditions, including depression, anxiety, and intestinal problems.
Oxytocin is produced in the hypothalamus, a part of the brain. Females usually have higher levels than males.
Alternative names for oxytocin
Alpha-hypophamine; manufactured versions – carbetocin, syntocinon and pitocin
What is oxytocin?
Oxytocin is produced in the hypothalamus and is secreted into the bloodstream by the posterior pituitary gland. Secretion depends on electrical activity of neurons in the hypothalamus – it is released into the blood when these cells are excited.
Metabolic effects of oxytocin: OT is secreted from the posterior lobe of the pituitary gland and binds to its receptor in peripheral tissues. In adipose tissue, it induces fatty acid oxidation and lipolysis, and formation of small adipocytes. Small adipocytes increase secretion of adiponectin and decrease leptin secretion, which improve insulin sensitivity in adipose tissue, liver, and muscles. In pancreas, it induces insulin secretion via phosphoinositide (PI) turnover and activation of protein kinase C, and regeneration of pancreatic β-cells. In liver and muscles, it enhances glucose uptake by stimulation of intracellular release of calcium, and activation of phosphoinositid-3-kinase (PI3K), calcium-calmodulin kinase kinase (Ca-CAMKK), and AMP-activated protein kinase (AMPK).
The two main actions of oxytocin in the body are contraction of the womb (uterus) during childbirth and lactation. Oxytocin stimulates the uterine muscles to contract and also increases production of prostaglandins, which increase the contractions further. Manufactured oxytocin is sometimes given to induce labour if it has not started naturally or it can be used to strengthen contractions to aid childbirth. In addition, manufactured oxytocin is often given to speed up delivery of the placenta and reduce the risk of heavy bleeding by contracting the uterus. During breastfeeding, oxytocin promotes the movement of milk into the breast, allowing it to be excreted by the nipple. Oxytocin is also present in men, playing a role in sperm movement and production of testosterone by the testes.
More recently, oxytocin has been suggested to be an important player in social behaviour.
In the brain, oxytocin acts as a chemical messenger and has been shown to be important in human behaviours including sexual arousal, recognition, trust, anxiety and mother–infant bonding. As a result, oxytocin has been called the 'love hormone' or 'cuddle chemical'.
Many research projects are undertaken, looking at the role of oxytocin in addiction, brain injury, anorexia and stress, among other topics.
Oxytocin is produced in the hypothalamus and released during sex, childbirth, and lactation to aid reproductive functions.
It has physical and psychological effects, including influencing social behavior and emotion.
Oxytocin is prescribed as a drug for obstetric and gynecological reasons and can help in childbirth.
Research shows that it may benefit people with an autistic spectrum disorder (ASD), anxiety, and irritable bowel syndrome (IBS).
Oxytocin is naturally produced in a part of the brain called the hypothalamus and distributed
both within the brain and to the rest of the body by way of the pituitary gland.
Artificial oxytocin nasal spray is thought to access the brain directly through the nerves
located inside the nasal cavity that are linked to the brain. Artificial oxytocin nasal spray
has been shown to affect activity in different parts of the brain, such as the prefrontal cortex,
amygdala, and the brain stem. The blood–brain barrier acts like a protective filter for the
brain by preventing unwanted molecules entering the brain from the blood stream, but it
can also prevent the entrance of large drug molecules, such as oxytocin. Small amounts of
the oxytocin nasal spray are sometimes swallowed, which is relatively harmless. Image
adapted from Quintana et al
How is oxytocin controlled?
Oxytocin is controlled by a positive feedback mechanism where release of the hormone causes an action that stimulates more of its own release. When contraction of the uterus starts, for example, oxytocin is released, which stimulates more contractions and more oxytocin to be released. In this way, contractions increase in intensity and frequency.
There is also a positive feedback involved in the milk-ejection reflex. When a baby sucks at the breast of its mother, the stimulation leads to oxytocin secretion into the blood, which then causes milk to be let down into the breast. Oxytocin is also released into the brain to help stimulate further oxytocin secretion. These processes are self-limiting; production of the hormone is stopped after the baby is delivered or when the baby stops feeding.
What happens if I have too much oxytocin?
At present, the implications of having too much oxytocin are not clear. High levels have been linked to benign prostatic hyperplasia, a condition which affects the prostate in more than half of men over the age of 50. This may cause difficulty in passing urine.
It may be possible to treat this condition by manipulating oxytocin levels; however, more research is needed before any possible treatments are available.
What happens if I have too little oxytocin?
Similarly, it is not fully understood at present if there are any implications of having too little oxytocin in the body. A lack of oxytocin in a nursing mother would prevent the milk-ejection reflex and prevent breastfeeding.
Low oxytocin levels have been linked to autism and autistic spectrum disorders (e.g. Asperger syndrome) – a key element of these disorders being poor social functioning. Some scientists believe oxytocin could be used to treat these disorders. In addition, low oxytocin has been linked to depressive symptoms and it has been proposed as a treatment for depressive disorders. However, there is not enough evidence at present to support its use for any of these conditions.
Foods That Boost Your Love Hormone
Avocados
The buttery avocado plays a crucial role in boosting energy and sexual drive. Avocados are beneficial for both men and women as they are loaded with all essential fats, vitamins and minerals.
Watermelon
Watermelon is called as a natural Viagra by researchers, as it is loaded with citrulline, an amino acid which can relax and dilate blood vessels improving blood flow to the extremities, leading to heightened sexual pleasure.
Spinach
The abundance of magnesium in spinach lowers inflammation and increases the blood flow, which help men in improving their vitality.
Green Tea
Green tea is the perfect beverage to spice up your sexual drive. The three magical components in green tea such as caffeine-theanine and ginseng help in boosting libido and improve sexual health.
Foods For Her
Coffee is a great drink that can boost libido in women, by balancing hormones and increasing sexual desire.
Foods For Him
Nutty almonds are abundant in omega 3 fatty acids, and they trigger the production of sex hormone testosterone in men and improve quality and vitality of the sperm. Pumpkin seeds, high in zinc too can help in boosting libido.
Serotonin is created by a biochemical conversion process that combines tryptophan, a component of proteins, with tryptophan hydroxylase, a chemical reactor. Together, they form 5-hydroxytryptamine (5-HT), or serotonin.
Serotonin is most commonly believed to be a neurotransmitter, although some consider it to be a hormone. It is produced in the intestines and the brain. It is also present in the blood platelets and the central nervous system (CNS).
As it occurs widely throughout the body, it is believed to influence a variety of body and psychological functions.
Serotonin cannot cross the blood-brain barrier, so any serotonin that is used inside the brain must be produced inside the brain.
Have you ever wondered what hormone is responsible for your mood and feelings? Serotonin is the key hormone that stabilizes our mood, feelings of well-being, and happiness. This hormone impacts your entire body. It enables brain cells and other nervous system cells to communicate with each other. Serotonin also helps with sleeping, eating, and digestion. However, if the brain has too much serotonin, it may lead to depression. If the brain has too much serotonin, it can lead to excessive nerve cell activity. It also helps reduce depression, regulate anxiety, and maintain bone health.
Serotonin is an important chemical and neurotransmitter in the human body.
It is believed to help regulate mood and social behavior, appetite and digestion, sleep, memory, and sexual desire and function.
There may be a link between serotonin and depression. If so, it is unclear whether low serotonin levels contribute to depression, or if depression causes a fall in serotonin levels.
Drugs that alter serotonin levels are used to treat depression, nausea, and migraine, and they may have a role in obesity and Parkinson's disease.
Other ways to increase body serotonin levels may include mood induction, light, exercise, and diet
How Does Your Body Use Serotonin?
Your body uses serotonin in various ways:
Mood
Serotonin is in the brain. It is thought to regulate mood, happiness, and anxiety.
Low levels of serotonin are linked to depression, while increased levels of the hormone
may decrease arousal.
Bowel Movements
Serotonin is found in your stomach and intestines. It helps control your bowel
movements and function.
Nausea
Serotonin is produced when you become nauseated. Production of serotonin increases to
help remove bad food or other substances from the body. It also increases in the
blood, which stimulates the part of the brain that controls nausea.
Sleep
Serotonin is responsible for stimulating the parts of the brain that control sleep and
waking. Whether you sleep or wake depends on the area is stimulated and which
serotonin receptor is used.
Blood Clotting
Serotonin is released to help heal wounds. Serotonin triggers tiny arteries to narrow,
which helps forms blood clots.
Bone Health
Having very high levels of serotonin in the bones can lead to osteoporosis, which
makes the bones weaker.
How Does Serotonin Impact Your Mental Health?
Serotonin helps regulate your mood naturally. When your serotonin levels are at a normal level, you should feel more focused, emotionally stable, happier, and calmer.
What Problems are Associated with Low Levels of Serotonin?
Low levels of serotonin are often associated with many behavioral and emotional disorders. Studies have shown that low levels of serotonin can lead to depression, anxiety, suicidal behavior, and obsessive-compulsive disorder. If you are experiencing any of these thoughts or feelings, consult a health care professional immediately. The sooner treatment starts, the faster you’ll see improvements.
What Problems are Associated with High Levels of Serotonin?
Serotonin syndrome can occur when you take medications that increase serotonin action leading to side effects. Too much serotonin can cause mild symptoms such as shivering, heavy sweating, confusion, restlessness, headaches, high blood pressure, twitching muscles, and diarrhea. More severe symptoms include high fever, unconsciousness, seizures, or irregular heartbeat. Serotonin syndrome can happen to anyone, but some people may be at higher risk. You are at a higher risk if you increased the dose of medication that is known to raise serotonin levels or take more than one drug known to increase serotonin. You may also be at risk if you take herbal supplements or an illicit drug known to increase serotonin levels. https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/serotonin https://www.medicalnewstoday.com/kc/serotonin-facts-232248
