Noveii Studies

studyblr of a 3rd year college student // Neuroscience & Developmental Psychology // '22 // Start where you are. Use what you have. Do what you can

[bn-studies]

neurotransmitters are so interesting I could study them for days ~

[tobeagenius]

Could you explain how antidepressants work, specifically SSRIs. I know they increase seretonin levels in the brain but how does that work?

Yes of course! So SSRI is an abreviation for Selective Serotonin Reuptake Inhibitor. Prozac is probably the most well known example of an SSRI medication used to treat depression, anxiety, eating disorders and sometimes PTSD. 

To understand how SSRIs work, we first need to look at where it takes effect. SSRIs work in your synapses; the gaps between neurones where neurotransmitters diffuse across to send a signal. And as I am oh so nice I’ve a made a some diagrams to explain:

Structure of A Synapse:

As you can see, when an impulse travels along the first neurone (known as the presynaptic neurone), it is stimulated to release neurotransmitters, in this case serotonin, across the gap (known as the synaptic cleft). These neurotransmitters then move by diffusion across the gap and bind to their receptors on the next neurone, known as the post-synaptic neurone. If enough neurotransmitter binds in a given time, the signal will then be carried down through that neurone (keyword here is enough; there is a threshold and if that is not met/exceeded, NO impulse AT ALL will be generated in the postsynaptic neurone). Since serotonin is a neurotransmitter that contributes to feelings of wellbeing, this resulting impulse promotes a generally good mood. However, serotonin tends to lack in those with depression which means it is harder for them to generate such impulses (as it is harder to meet the threshold). So how do SSRIs fit in and work to compensate for this? 

The Process Of Reuptake

You’ll remember SSRI stands for selective serotonin reuptake inhibitor, in other words it stops serotonin from being absorbed back into the neurone it came from. This process is called reuptake. Reuptake happens through channels like the one shown in pink, where the serotonin molecules pass through so they can be used by the neurone again for the next impulse. 

The Action Of SSRIs

What the SSRI does is block this reuptake channel, which leaves more serotonin in the synaptic cleft. As a result, more serotonin can bind to receptors on the post-synaptic neurone which creates a stronger signal more likely to exceed the threshold. The overall result is that the feelings of sadness and emptiness that are caused by depression are counteracted by the increased effect of serotonin. 

[biomedicool]

GABA

γ-Aminobutyric acid (GABA) is the principal inhibitory neurotransmitter known to counterbalance the action of excitatory glutamate, and is responsible for at least 40% of inhibitory synaptic processing throughout the central nervous system (CNS) (Bowery and Smart, 2006). 

Binds to transmembrane receptors 

Initiates the opening of ion channels

allowing either Cl- ions to flow into the cell, or K+ ions to flow out. 

This results in a negative change in the transmembrane potential, and usually consequent hyperpolarization. Hyperpolarization increases the threshold which must be reached before firing, in turn reducing the probability of action potential initiation, and causing neuronal inhibition.

Due to the wide distribution and utilization of GABA, early GABAergic drugs had very generalized effects on CNS function. More recently, at least two distinct classes of GABA receptor, GABAA and GABAB, have been identified (Olsen and DeLorey, 1999). 

GABAB receptors 

G protein-coupled

indirectly link to K+ channels

can decrease Ca2+ conductance and inhibit cAMP production 

via intracellular mechanisms linked to their G protein. 

The GABAA receptor

exists as part of a larger, ligand gated macromolecular complex 

with five major binding domains for a variety of neurotransmitters.

GABA also has roles outside of the CNS, which made it difficult initially to define as a neurotransmitter. It is secreted in pancreatic β-cells, where it binds to GABA receptors on the neighbouring islet α-cells. This inhibits them from secreting glucagon, which would counteract the effect of the insulin produced by the β-cells (Rorsman et al., 1989). GABA has also been detected in many peripheral tissues, and immune cells can express receptors for GABA.

[biomedicool]

Neurotransmitters

Central nervous system

Glutamate 

GABA 

Glycine 

Dopamine 

Serotonin 

Noradrenaline 

Histamine 

Orexin 

Endorphins 

Peripheral nervous system 

Noradrenaline 

Acetylcholine 

Neurotransmitter synthesis/packaging 

Some neurotransmitters are readily available amino acids eg Glutamate, glycine 

Some are synthesised by the cells that secrete them eg GABA, noradrenaline, dopamine 

Noradrenaline synthesis:

Packaging

In the presynapse, neurotransmitter is contained in vesicles 

The neurotransmitter must be packaged into the vesicle ready for release 

Uses transporters and proton gradients to package 

[packaging and release - above]

Neurotransmitter release is quantal – Each vesicle contains the same amount of neurotransmitter 

Therefore it is the number of vesicles fusing which determines the post synaptic potentials 

membranes must fuse for release - membrane fusion is energetically unfavourable so must be catalysed by something

SNARE Hypothesis 

Proteins on the presynaptic membrane ‘grab’ proteins on the vesicle membrane 

These SNARE proteins pull the two membranes close together 

SNARE proteins provide most of the energy for membrane fusion

v-SNARE (VAMP2) – on vesicle membrane 

t-SNAREs (syntaxin1A, SNAP-25) on target membrane 

Bind together to make SNARE complex 

 SNARE ‘zippering’ forces the membranes close together 

Spontaneous, highly energetically favourable 

Once assembled, they require ATP hydrolysis to separate them 

 Ca2+ binding to synaptotagmin provides extra energy to fuse the membranes

Neurotransmitter release

synaptic vesicle release sites are highly organised and regulated

exocytose into synaptic cleft

presynaptic active zone:

Neurotransmitter detection

Ionotropic (ion channel coupled) – Glutamate, GABA, Glycine 

Metabotropic (G-protein coupled) – monoamines, histamine etc. 

Some have both kinds, e.g. glutamate, GABA 

Ionotropic responses are faster 

Metabotropic responses can have more diverse effects 

Glutamate receptors

Glutamate is the main excitatory neurotransmitter in the brain 

Three classes of ionotropic receptor – AMPA – NMDA – Kainate 

 Named after pharmacological agonists 

All let in positive ions when they bind glutamate 

Glutamate also has a family of metabotropic receptors – mGluRs – These modulate neurotransmission 

AMPA Receptors 

 Main fast excitatory receptor 

Strength of a synapse is largely determined by its complement of AMPARs

 More AMPAR in the post-synaptic membrane = stronger synaptic transmission 

NMDA Receptors 

Minor role in postsynaptic firing 

Major role is in synaptic plasticity 

NMDA receptors are calcium permeable 

require strong neurotransmitter release to open 

[notebookist]

09.07.20 | i really liked these pens my friend had, but neither of us knew what brand they were since the label wasn't in english. as a surprise, last week he gave me one!! it writes like a dream, but i need better paper. (an excuse to buy a new notebook? no, no, i would never!!)

ft. some frantic thesis preparation notes

[study-well]

Some general resources:

Chemistry Glossary

Chemistry Exam Survival Guide

Toolbox – interactive graphing, tables, and calculators

Make virtual chemistry models

Interactive periodic table

Another site for making virtual chemistry models

Virtual labs – covers stoichiometry, thermochemistry, eq1uilibrium, acid base chemistry, solubility, oxidation/reduction and electrochemistry, analytical chemistry/lab techniques

Concept tests

Chemistry Science Fair Project Ideas

OChem Reaction Bank

Interactive chem simulations

Chemical calculations

The Chem Blog

Molecule of the day

Free chemistry drawing software

Laboratory Safety - Laboratory safety for the chemistry classroom

Periodic Table of Videos - Brady Haran

On this day in chemistry… - a history of chemistry

The faces of chemistry

Experimentation hub -  explore and enjoy our experiments to increase engagement in scientific investigation, develop new skills and enhance your knowledge.

Understanding journals - including reading articles, referencing, and example articles.

Resources for specific topics:

Stochiometry – the mole, molarity and density, reaction stoichiometry and limiting reagents, empirical formula and mixtures, gravimetric analysis

Themochemistry – energy and enthalpy, entropy

Kinetics – phenomenological and mechanistic kinetics

Equilibrium – LeChatlier’s principle, progress of reaction, equilibrium calculations, common ion effect

Acid base chemistry – strong acid and bases, weak acids and bases, buffer solutions, acid/base titrations

Solubility – solubility product, solubility and PH, common ion effect

Oxidation/Reduction and Electrochemistry – standard reduction potentials, galvanic cells

Analytical chemistry/ Lab techniques – reaction stoichiometry and limiting reagents, acid/base titrations, redox titrations, gravimetric analysis, UC/Vis spectroscopy

Physical chemistry – quantum mechanics, spectroscopy

Properties of solutions – intermolecular forces, colligative properties

Textbooks:

Chemistry Virtual Textbooks, Stephen Lower

Organic Chemistry, Tim Soderberg

Organic Chemistry I, George Mhehe

Environmental Chemistry, Dejene Tessema

Virtual Organic Chemistry

Industrial Chemistry, Helen Njenga

Inorganic Chemistry, Chrispin Kowenje

Physical Chemistry I, Onesmus Munyaki

General Chemistry, Principles, Patterns and Applications

Chemistry Books - a variety of chemistry textbooks

Chemistry Tutorials/Guides:

Atoms, Molecules, and Ions

Chemical reactions and stoichiometry

Electronic structure of atoms

Periodic table

Chemical bonds

Gases and kinetic molecular theory

State of matter and intermolecular forces

Chemical equilibrium

Acids and bases

Acid base equilibria and solubility equilibria

Thermodynamics

Redox reactions and electrochemistry

Kinetics

Nuclear chemistry

Organic Chemistry Tutorials/Guidelines:

Structure and bonding

Dot structures

Hybridization

Bond-line structures

Electronegativity

Resonance and acid base chemistry

Counting electrons

Resonance structures

Organic acid-base chemistry

Alkanes, cycloalkanes and functional groups

Naming alkanes

Naming alkanes, cycloalkanes, and bicyclic compounds

Conformations of alkanes

Conformations of cycloalkanes

Functional groups

Stereochemistry

Chirality

Enantiomers

Stereoisomeric relationships

Subsituation and elimination reactions

Free radical reaction

Sn1 vs Sn2

Nucleophilicity and basicity

Elimination reactions

Sn1/Sn2/E1/E2

Sn1 and Sn2

Alkenes and alkynes

Naming alkenes

Alkene reactions

Alkene nomenclature

Alkene reactions

Naming and preparing alkynes

Alkyne reactions

Alcohols, ethers, epoxides, sulphides

Alcohol nomenclature and properties

Synthesis of alcohols

Reactions of alcohols

Nomenclature and properties of ethers

Synthesis and cleavage of ethers

Nomenclature and preparation of epoxides

Conjugation, Diels-Alder, and MO theory

Addition reactions of conjugated dienes

Diels-Alder reaction

Molecular orbital theory

Aromatic compounds

Naming benzene derivatives

Reactions of benzene

Aromatic stability

Electrophilic aromatic substitution

Directing effects

Other reactions and synthesis

Aldehydes and ketones

Introduction to aldehydes and ketones

Reactions of aldehydes and ketones

Carboxylic acids and derivatives

Naming carboxylic acids

Formation of carboxylic acid derivatives

Nomenclature and reactions of carboxylic acids

Nomenclature and reactions of carboxylic acid derivatives

Alpha carbon chemistry

Formation of enolate anions

Aldol condensations

Amines

Naming amines

Spectroscopy

Infrared Spectroscopy

UV/Vis Spectroscopy

proton NMR

Careers:

A future in Chemistry

What can I do with my chemistry degree?

Chemistry Careers - American Chemical Society

What to do with a degree in chemistry - The Guardian

[noveii]

Follow my studyblr here

[areistotle]

hey friends!! i’m starting to get a lot of requests about chemistry and since i recently started studying the basics of chemistry i wanted to help all of you [and myself] out by making a chemistry masterpost, so here it is :]

studying chem

how 2 study general chemistry

ten ways to pass ur next chem exam

chem study hints

tips for studying chemistry

lecture notes

ap chem notes

how 2 write notes

fun stuff kinda??

the periodic table of elements

fun thing about moles

learn about women in chemistry!!!!

chemistry timeline

books + things

best chem books on amazon

best chem books on goodreads

for general readers

for the college student

links + website resources

crash course: chemistry

chemistry on khanacademy

sparknotes chemistry

chem collective

royal society of chemistry

high school chem

careers in chemistry

what can i do with a degree in chemistry?

a future in chemistry

why study chemistry?

my masterposts

notes, studying, and self-study resources

self-study resources

supplies

igcse resources

improving your handwriting

how to studyblr

literature masterpost

organisation

aesthetically pleasing notes

annotating

studying a foreign language

really great apps

math

college + uni

motivation

biology

space!!!!

+ more

hope this helps you all <3 good luck fellow chemistry students + i hope you get where you truly want in life!!! if you wish to talk to me or request a masterpost, just message me!!

[historixn]

you know, life doesn’t have to be competitive. you don’t have to get in the very best university; you don’t have to get the highest paying career there is. you don’t need to compare and compete with everyone else in the world. you need to do what’s right for you. you need to relax, take a breath, and say ‘what do i want, for myself, to live as i want to’. and, if that involves high ambitions, then that’s fine. because you chose those ambitions on what you desire as an individual, and not on what is expected in order to succeed. let’s be ourselves this year.

[marias-studyblr]

self discipline tips

here are tips I discovered very recently:

something is better than nothing. 5 minutes of work are better than zero. Just because you missed something on your schedule doesn’t mean you can’t still work on it, even for 5 minutes. Grow and build on this.

second drafts / reviews can be done after.

Don’t think you are going to do your very best work on the first try. Take the weight of perfectionism off your shoulders.

don’t think about doing it. just do it as fast as you can.

build on your productivity, not your failures.

If you come from a past of procrastinating and now feel motivated to change and discipline yourself, do NOT try to do everything at once.

if you have a set of different goals to accomplish, begin with the most important one. Wait until the rotine of working for that one settles in (you feel productive and comfortable-ish), and then begin with the next. Repeat.

this way you’ll be building your way up and not juggling everything at the same time, hoping everything works out.

be patient with yourself, you’ll get there!

set smaller deadlines for your goals

have monthly and weekly-ish deadlines

e.g. if you are doing a project, due 22nd Feb, set personal deadlines, like have Introduction written by 2nd Feb, have Methods written by 10th Feb, have project complete by 18th Feb.

take them as seriously as you possibly can, don’t miss out on yourself.

write realistic daily tasks and don’t stop until you finish them. after them you can do whatever you want

on writing realistic daily tasks, the secret is knowing you can only do so much in one day, but trusting you can accomplish everything in the course of any period of time (a week, or 2 weeks or a month, etc.) because you will combine the work from all these different days.

it’s very tempting to write down all the tasks you need to accomplish in one day to just get over with it, but the real deal is you won’t accomplish half of them. You’ll feel very unproductive then, wich leads to demotivation.

spread daily tasks in the time necessary.

have a consistent sleep schedule.

if your mind isn’t ready everything will fall apart.

have one rest day per week where you plan nothing, do whatever you want except studying. this can be harder than you expect!

(don’t forget these are effective only if you actually put them into practice! good luck babes!!)

[digoxin-purpurea]

apply for jobs you’re not qualified for! audit upper-level classes! get drunk with your TAs! see that poster advertising that lecture series? go there take notes and ask questions! thank the presenter for talking about this topic you love! if the class is full before you register, email the professor and ask if they can squeeze you in! RAISE YOUR HAND! tell the disability accomodation office to do their goddamn job! ask for help! file complaints! go to class in your pajamas and destroy the reading! you got this! you KNOW you got this! be arrogant enough to learn EVERYTHING! take your meds! punch a velociraptor in the dick! fear is useless and temporary! glory is forever! shed your skin and erupt angel wings! help out! spread your sun!

i had a really good morning! you deserve a really good morning! kill anyone who says you don’t and build a throne from their bones!

[sirjefetheboss-deactivated20210]

Oddly inspiring

[academiix]

How to Learn More in Less Time, tips by academiix 

[positiveautistic-deactivated202]

It’s never too late to start being who you want to be

[sweetlikeacherry]

[equatorjournal]

Ellsworth Kelly, Green from the series Line Form Color, 1951

[z-anthias]

stop overthinking. stop being so scared about being outside your comfort zone. just say yes. live a little. experience new things. that’s the only way you’ll grow.

[rabbitinthemeadow]

Shifting through that sweetly fragrant memory // Part 13

[apoherm-deactivated20231020]

“But how could you live and have no story to tell?”

— Fyodor Dostoyevsky, White Nights (via larmoyante)