This pdf is about the Neuron, Glia cells & Neurotransmitters. For more details visit on YouTube; @SELF-EXPLANATORY; Neuron, Glia cells, Neurotransmitter: https://youtu.be/Nk1sYUkHn1g Thanks...!

1. Saba Parvin Haque
MSc in Neuroscience
from “Sophia College For
Women”, Mumbai. https://www.youtube.com/chann
el/UCAiarMZDNhe1A3Rnpr_WkzA

2. https://www.ninds.nih.gov/Disorders/Patient-
Caregiver-Education/Life-and-Death-Neuron
➢ The central nervous system (which includes the brain and spinal cord) is made up
of two basic types of cells: neurons (1) and glia (4) & (6).
➢ Glia outnumber neurons in some parts of the brain, but neurons are the key players in
the brain.
➢ Neurons are information messengers.
➢ They use electrical impulses and chemical signals to transmit information between
different areas of the brain, and between the brain and the rest of the nervous system.
➢ Everything we think and feel and do would be impossible without the work of neurons
and their support cells, the glial cells called astrocytes (4) and oligodendrocytes (6).
➢ Neurons have three basic parts: a cell body and two extensions called an axon (5)
and a dendrite (3).
➢ Within the cell body is a nucleus (2), which controls the cell’s activities and
contains the cell’s genetic material.
➢ The axon looks like a long tail and transmits messages from the cell.
➢ Dendrites look like the branches of a tree and receive messages for the cell.
➢ Neurons communicate with each other by sending chemicals, called
neurotransmitters, across a tiny space, called a synapse, between the axons and
dendrites of adjacent neurons. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Life-and-Death-Neuron
Figure: The architecture of the neuron

3. https://images.app.goo.gl/uSkUVepZ7Bi2yg6p6
There are three classes of neurons:
1.Sensory neurons carry information from the sense organs
(such as the eyes and ears) to the brain.
2.Motor neurons control voluntary muscle activity such as
speaking and carry messages from nerve cells in the brain to
the muscles.
3.All the other neurons are called interneurons.
• Scientists think that neurons are the most diverse kind of
cell in the body. Within these three classes of neurons are
hundreds of different types, each with specific message-
carrying abilities.
Source: Brain Basics: The Life and Death of a Neuron | National Institute of Neurological Disorders and Stroke. (n.d.). https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Life-and-Death-Neuron

4. ➢Glia are non-neuronal cells (i.e. not nerves) of the brain
and nervous system.
➢There are a variety of subtypes of glial cells,
including astrocytes, oligodendrocytes, and microglia,
each of which is specialized for a particular function.
➢Neurons have axons and dendrites. However, glia, unlike
neurons, cannot generate action potentials (also known
as spikes, or nerve impulses).
https://images.app.goo.gl/V8Z6tbKSJoKPoSXQ6
Figure: Glial cells

5. Figure: Major types of glial cells in the nervous system
Central Nervous System
❑ Microglia
❑ Macroglia:
• Astrocytes
• Oligodendrocytes
Peripheral Nervous system
❑ Schwann cells
❑ Satellite cells
❑ Enteric glial cells

6. ➢Microglia are the brain’s immune cells, serving to protect it against injury and disease.
➢Microglia identify when something has gone wrong and initiate a response that removes the toxic agent and/or
clears away the dead cells.
➢Thus microglia are the brain’s protectors.
➢However, the situation may be different in neurodegenerative disorders such as Alzheimer’s disease—there is
evidence that microglia may become hyperactivated, promoting neuroinflammation that can lead to the
characteristic toxic protein deposits seen in Alzheimer’s (amyloid plaques and neurofibrillary tangles).
➢Finally, recent work shows that microglia play a role in the developing brain.
➢Normally, far more synapses are created than are needed, with only the strongest, most important ones
surviving.
➢Microglia directly contribute to this synaptic ‘pruning’ process by eating up the synapses tagged as
unnecessary.

7. Central Nervous System:
Ependymal cells: Ependymal cells line the spinal cord and ventricles of the brain. They are
involved in creating cerebrospinal fluid (CSF).
Radial glia: Radial glial cells are progenitor cells that can generate neurons, astrocytes and
oligodendrocytes.

8. ➢Astrocytes are star-shaped cells that maintain a neuron’s working environment. They
do this by controlling the levels of neurotransmitter around synapses, controlling the
concentrations of important ions like potassium, and providing metabolic support.
➢But astrocytes don’t just maintain the environment around synapses. An active area of
research addresses how astrocytes modulate how neurons communicate.
➢Because astrocytes have the ability to sense neurotransmitter levels in synapses, and
can respond by releasing molecules that directly influence neuronal activity, astrocytes are
increasingly seen as important for modifying synapses.

9. ➢Oligodendrocytes provide support to axons of neurons in the
central nervous system, particularly those that travel long distances
within the brain.
➢They produce a fatty substance called myelin, which is wrapped
around axons as a layer of insulation.
➢Similar in function to insulation layers around power cables,
the myelin sheath allows electrical messages to travel faster, and
gives white matter its name—the white is the myelin wrapped
around axons.
➢Multiple sclerosis is caused by a loss of the myelin sheath around
neurons.
• Major glial cells in the brain include oligodendrocytes (blue),
astrocytes (green) and microglia (maroon).
• Neurons are shown in yellow, with the blue of oligodendrocytes
forming the myelin sheath around the axon.

10. Schwann cells: Similar to oligodendrocytes in the central nervous system, Schwann
cells myelinate neurons in the peripheral nervous system.
Satellite cells: Satellite cells surround neurons in the sensory, sympathetic and
parasympathetic ganglia and help regulate the chemical environment. They may
contribute to chronic pain.
Enteric glial cells: Enteric glial cells are found in the nerves in the digestive system.

11. o 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.
o 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.
o A neurotransmitter influences a neuron in one of three ways: excitatory,
inhibitory or modulatory.
o 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.
https://qbi.uq.edu.au/files/27919/what-are-neurotransmitters-QBI.jpg
Fig; Neurotransmitters

12. oNeuromodulators 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.
o 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.
Fig: Neurotransmitters
https://images.app.goo.gl/oe48B4zgvSo6Y9Tf6

13. o 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
(excitatory neurotransmitter).
o 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.
o 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.
o 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.
o 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.
o 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.

14. •Brain Basics: The Life and Death of a Neuron | National Institute of Neurological Disorders and Stroke,
https://www.ninds.nih.gov/health-information/patient-caregiver-education/brain-basics-life-and-death-
neuron#:%7E:text=Neurons%20are%20information%20messengers.,rest%20of%20the%20nervous%20system.
•What are glia?. Queensland Brain Institute. https://qbi.uq.edu.au/brain-basics/brain/brain-physiology/what-are-
glia
•Types of glia. Queensland Brain Institute. https://qbi.uq.edu.au/brain-basics/brain/brain-physiology/types-glia
•What are neurotransmitters?. Queensland Brain Institute. https://qbi.uq.edu.au/brain/brain-functions/what-
are-neurotransmitters

15. THANK YOU
Do Like and Subscribe
My Channel...!!