25. Neurobiology 2
Вставка
- Опубліковано 22 жов 2024
- MIT 7.013 Introductory Biology, Spring 2011
View the complete course: ocw.mit.edu/7-0...
Instructor: Hazel Sive
Professor Sive discusses the nervous system in more detail, focusing on pumps and channels, and synapses.
License: Creative Commons BY-NC-SA
More information at ocw.mit.edu/terms
More courses at ocw.mit.edu
For me her lectures are great! pure pronunciation, good tempo, and many clear images :) thank You for opportunity to watch it!
(On Wednesday of January 25, 2023). Biology and the Neurobiology therein: Pumps and Channels with the Plasma Membrane of Neurons (Basic Unit of the Nervous System): 1) Action Potential (AP) is Sequenced as Resting Potential (Charge Differential), Threshold (Leading to AP), to Repolarization (Resetting of Resting Membrane Polarity (+55mv outside versus 60-mv inside);2) Na+/K+ Pump with Mechanics of Sodium Out Potassium In (Always ON); 3) K+ Channels (Open Cl-, N+) Always open but are essential in Repolarization and RP; 4) Voltage Gated Sodium (VG-Na+) Channel is Closed outside Threshold to Activation Momentum (At RP and ReP) and is probably the Unidirectional ion valve mechanism; 5) Lastly, VG K+ Channel (VG-K+) Opens at Post-AP and gradually contributes to Resting AP (Repolarization Phase); The Synapse (Vesicular Release Site or Neurotransmitter [Release/Reception] Site) and Mechanics (Structures Therein Involved) is the Connection Between Neurons (One Neuron synapses with 100k) visualization via Radio-isotopic Pulse Emission (Tags Specifically to the Synapses on Dendrites show a Plethora of Interconnectivity); Brain Neurons (Central Nervous System Category) Synapsed at this Rate with a Possible 10 to 10 Exponent (Weight of 1.5 kg [10 Billion[) permits a complexity of Intercommunication and Synergy. Mechanics Therein: 1) Voltage-Gated Calcium (Ca2+) Channels; 2) Ligand-Gated (Second Messenger-Regulated) Ion Channels; 3) Neurotransmitter Signaling (Chemical Synapse Ideation) to contrast with the Electrical (Fast) Intercellular Signal Transduction. Action Potential Fundamentals: 1) Action Potential (AP) All-or-None Occurrence (Depolarization Occurs or Not); 2) Frequency (Whereas Amplitude Does Not as A Factor of Signal Transduction Modulation); 3) Resting Potential (RP) Changes as A Factor of Influence; 4) Threshold Potential (TP) and Action Potential (AP) do not Change (Zero-sum Morphology). Axonal (Axon Structure) Morphology and Physiologic Function: 1) AP Propagation Via VG-Na+(Axonally) then VG-Ca2+ Channels at the Synapse; 2) Pre-synaptic Cleft (Neuron 1) Pre-Synaptic Neuron Exocytosis of Neurotransmitter (NT) leading to Post-Syanpatic Neuron Reception (Ligand-Receptor Binding Mechanics) Effecting Ionic Flux or Movement an Thereby Effecting AP Decision (An ON or OFF Ideation); This Process can be Surmised as an Electrical-Chemical Diffusion to Effect a Target Organ, Tissue or Cell (via ultimately an Action Potential). The Basic of Signal Transduction via First Messenger Signaling (Neuronal Tissue Transmission); 3) Summation is total (1) Spatial and 2) Temporal) synaptic inputs of Recipient Cell (Dendrite and Cell Body [Soma]) and ultimately the Axon Hillock (AH). Synapse Type: 1) Excitatory Synapse is bring AP to Threshold Potential (TP); 2) Inhibitory bring AP further away to TP 3) Ionic-Mediation or Flux Status Therein (Cl- Anions are usually Inhibitory while influx of Na+,K+,H+ [Cations] are Stimulatory Conventionally); 3) Neurotransmitter Multiplicity Possible (Peptides, Amino Acids, Nucleotides (NAD+), Small Molecules) and Neurotransmitters (Glutamate/Adenine Excitatory Function) effecting an Alert Predisposition; 2) Inhibitory Action of Somnia, Somnolence or (Anxiolysis) by NTs as (Gamma Aminobutyric Acid [GABA] and Glycine [AA]); or Both Effects by Acetylcholine (Ach) Muscle Activity (M and N Receptors) and Anesthesia, Serotonin (Somnolence and Mood), Dopamine (Depression and Hedonism); Receptor in (First Messenger Ligand-Receptor signal Transduction); 1) Ionotropic Channels (Ligand-Gated Channels) are Fast and Effective (millisecond range); 2) Metabotropic (Via Second Messenger System via G-Protein System) are slow and Refractory (Greater than one Second to Effect); 3) Neurotransmitter Multiplicity in Isomeric Receptivity (Serotonin has 14 Receptors Possible outside Normal 5-HT Reception) of which 1) a Ligand-Gated Sodium (Na+) Channel; 2) G-Protein Coupled Receptor (GPCR) Signal Transduction (ST); PhD Hazel Sive is one Great Biologist, Chemist, Geneticist and, as it turns out, Pharmacologist (For all the Pharmacologic Manipulation Within the Neurotransmitter Signal Transduction Domain These Days possible). Es geht Sehr gut zu lernen mit Professorin Sive. Heil!
39:48 what's happening when different types of liquid caffeine affects bothe excited and tiredness differently. Exampke, coffee I can drink and go to sleep aftwards. Another is drinking Mountain Dew or Red Bull has the correct effect.
I think she is an organized lecturer.
Great neuron and dendrite image at 15:20.
Looks like christmas lights
i love it
Thanks ❤️🤍
This is helpful ❤️🤍
Last lecture she said there were trillions of neurons in the human brain. Now, she says there are 'at least 10 billion'. There are about 86 billion neurons in the human brain. Say it with me: 86 billion. Also, she says adult human as though it's important that we specify adult vs child. A newborn has about the same number of neurons as an adult: 86 billion.
That's fascinating. Where did you read all that?
@@alrightjaihere Azevedo et al. (2009) "Equal numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled-up primate brain" published in the Journal of Comparative Neurology.
@@matthewnordlund Thanks man!
Thankyou
Why do they write in block letters it's time consuming
She says the synapse is about 30 nm. But, in a previous lecture, she showed a 100x100 nm section of brain. The synapses modeled there by slicing and panel reconstruction were nowhere near 30% of the dimension of the plane. One or the other is an inaccurate measure.
The section of the brain she showed in the previous video is 100 um x 100 um.
STFU
so smart
Very beautiful sweet ❤❤❤