The document discusses the structure and function of neurons. It describes how neurons transmit signals through dendrites, the cell body and axon. An action potential is generated when the membrane potential reaches threshold. This involves the opening of voltage-gated sodium and potassium channels. Action potentials propagate along axons through continuous conduction in unmyelinated axons or saltatory conduction in myelinated axons between nodes of Ranvier. Factors like myelination, axon diameter and temperature can influence conduction velocity.
these slides contain a brief introduction of neurons and its classification as well as details of generation of action potential, resting potential and eletrotonic potential.
these slides contain a brief introduction of neurons and its classification as well as details of generation of action potential, resting potential and eletrotonic potential.
Action potential By Dr. Mrs. Padmaja R Desai Physiology Dept
To study the Concept of Action Potential and describe the stages of action potential.
Ionic basis of Action Potential & its Propogation.
Properties of Action Potential.
Types action Potential
this ppt shares what synapses are and how information of one neuron is transmitted to other through the synapses. it also includes the properties and plasticity of synaptic transmission
it is very useful content for the basic knowledge of motor units .
Dedicated to my father shri satyaveer singh , my mother bateri devi and the entire lnipe family .
This presentation focuses on detail of the contraction of the contractile fibers in the muscles. short introduction to the ion channels, different potentials and phases working on the contraction of the muscles.
Reference: Anatomy, Physiology & Pathophysiology by Gerard J. Tortora
Action potential By Dr. Mrs. Padmaja R Desai Physiology Dept
To study the Concept of Action Potential and describe the stages of action potential.
Ionic basis of Action Potential & its Propogation.
Properties of Action Potential.
Types action Potential
this ppt shares what synapses are and how information of one neuron is transmitted to other through the synapses. it also includes the properties and plasticity of synaptic transmission
it is very useful content for the basic knowledge of motor units .
Dedicated to my father shri satyaveer singh , my mother bateri devi and the entire lnipe family .
This presentation focuses on detail of the contraction of the contractile fibers in the muscles. short introduction to the ion channels, different potentials and phases working on the contraction of the muscles.
Reference: Anatomy, Physiology & Pathophysiology by Gerard J. Tortora
This explains in detail about the different nerve potentials like Resting Membrane Potential and Action Potential.
https://www.youtube.com/channel/UC1QhJfPiWnmk2WpKVH1fzrQ
Subscribe and share for more topics of Neurophysiology.
The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. The presentation provides a simplified overview of the nervous system and its functions
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
2. Dendrite conducts signal from a sensory cell or
neighbouring neuron towards the cell body.
Axon conducts signal away from cell body to another
neuron or effector cell.
Axon ending relays signal to next neuron or effector
cell.
3. Difference in voltage b/w the inside & outside of the
cell as measured across the cell membrane.
When a neuron is not being stimulated, it maintains a
resting potential
Ranges from -40mV to -90mV
Average about -70mV
4. Is the entire series of charges which contribute
towards the changes in membrane potential.
Occurs in response to a threshold stimulus
Either ocurs completely/it does not occur at
all(all/none principle)
Has 2 main phases:
Depolarising phase: -ve memberane potential
becomes less –ve reaches zero & then becomes +ve
Repolarising phase: the memberane potential is
restored to the resting state of -70mV
5. Following the repolarising phase, there may be an
after hyperpolarising phase, during which the
memberane potential temporarily becomes more –ve
than the resting level
Caused by volage gated ion channels
Voltage gated Na+ channels
Activation & inactivation phase
At rest, activation gate closed, inactivation
gate open
Transient influx of Na+ causes the
membrane to depolarize
6. Voltage gated K+ channels
Single activation gate i.e, closed in the
resting state
K+ channels opens slowly
Efflux of K+ repolarizes the memberane
• The after hyperpolarizing phase occurs when the
voltage gated K+ channels remain open after the
repolarizing phase ends
• Action potential occurs in the memberane of the
axon when depolarisation reaches a certain level –
Threshold(abt -55mV in the neuron)
7. Threshold in a particular neuron is usually constant
An action potential will occur in response to a
threshold stimulus & not to a subthreshold stimulus
Several action potentials will form in response to a
supra threshold stimulus
8.
9.
10.
11. When a stimulus causes the memberane of the axon to
depolarise to threshold,
voltage gated Na+ channels open rapidly
rapid influx of Na+ ions into the cell
inside of the cell membrane become more +ve than
outside
This change is called depolarisation
Membrane potential changes from -55mV to +30mV
12. Each voltage gated Na+ channels have 2 separate
gates, an activation gate(AG) & an inactivation
gate(IAG)
In resting state,
IAG is open
AG is closed
Na+ cannot move into the cell
In activated state,
Both AG & IAG are open
Inflow of Na+
13. As more channels open
Na+ inflow increases
Membrane depolarises further
More Na+ channels open
This is an example for +ve feedback mechanism
14. After the AG of the voltage gated channels open, the
IAG closes & it is in an inactivated state
In addition to opening voltage gated Na+ channels, a
threshold level depolarisation also opens voltage gated
K+ channels
Opening of voltage gated K+ channels occurs at about
the same time the voltage gated Na+ channels closes
The slower opening of voltage gated K+ channels &
closing of previously open Na+ channels produce the
repolarising phase
15. Slowing of Na+ inflow & acceleration of K+ outflow
causes the memberane potential to change from
+30mV to -70mV
Repolarisation allows inactivated Na+ channels to
revert to resting state
16. • While the voltage gated K+ channels are open,
outflow of K+ may be large enough to cause an after
hyperpolarising phase of an action potential
• During this phase, the voltage gated K+ channels
remain open & the memberane potential becomes
even more –ve (-90mV)
• As the voltage gated K+ channels close, the
memberane potential returns to the resting level of -
70mV
17. The period of time after an action potential begins
during which an excitable cell cannot generate another
action potential in response to a normal threshold
level
During an absolute refractory period, even a strong
stimulus cannot initiate a 2nd action potential
This period coincides with the period of Na+ channel
activation & inactivation
Large diameter axons have a larger surface area &
have a brief absolute refractory period of about
0.4mSec
18. Small diameter axons have absolute refractory periods
as long as 4mSec
The relative refractory period is the period of time
during which a 2nd action potential can be initiated,
but only by a larger than normal stimulus
It coincides with the period when the voltage gated
K+ channels are still open after inactivated Na+
channels have returned to their resting state
19. To communicate information, action potentials must
travel from where they arise at the trigger zone of the
axon to the axon terminals
It is not decremental
Keeps its strength as it spreads along the membrane
This mode of conduction is called propagation
20. Each action potential in its rising phase, reflects a
reversal in membrane polarity
+ve charges due to influx of Na+ can depolarise the
adjacent region to threshold
So the next region produces its own action potential
The previous region repolarises back to the resting
membrane potential
Signal does not go back towards the cell body
21.
22. 2 ways to increase velocity of conduction
Axon has a larger diameter
Axon is myelinated
There are 2 types of conduction
1. Continuous conduction
2. Saltatory conduction
23. Involves step by step depolarisation & repolarisation
Ions flow through their voltage gated channels
Occurs in unmyelinated axons & in muscle fibres
Action potential propagates only a relatively short
distance in a few milliseconds
24. Occurs along myelinated axons
Occurs because of uneven distribution of voltage
gated channels
Few voltage gated channels are present in regions
where a myelin sheath covers the axolemma
At the Nodes of Ranvier, the axolemma has many
voltage gated channels
25. Current carried by Na+ & K+ flows across the
membrane mainly at the nodes
When an action potential propagates along a
myelinated axon, an electric current flows through the
extracellular fluid surrounding the myelin sheath &
through the cytosol from 1 node to the next
Action potential at the 1st node generates ionic
currents in the cytosol & extracellular fluid that
depolarize the membrane to threshold opening Na+
channels at the 2nd node
26. The resulting ion flow through the opened channels
constitutes an action potential at the 2nd node
Then the action potential at the 2nd node generates an
ionic current that opens voltage gated Na+ channels at
the 3rd node & so on
Each node repolarizes after it depolarises
27.
28. Amount of myelination
Action potentials propagate more rapidly along myelinated
axons than along unmyelinated axons.
Axon diameter
Large diameter axons propagate action potentials faster than
smaller ones due to their large surface area.
Temperature
Axons propagate action potentials at lower speed when
cooled.
