neuro stuffff Flashcards
the pioneers of neuro science
- Charles Sherrington
- Santiago Ramón y Cajal (1852–1934).
Structure of an animal cell:
- Mitochondrion is a structure that performs a metabolic activity.
- Ribosomes: sites for cell-synthesization of protein molecules
- All have a nucleus except red blood cells
motor vs sensory neuron
Motor neuro: neuron that receives execution from other neurons and conducts impulses to a muscle.
Sensory Neuron: neuron that is highly sensitive to a specific type of stimulation
white matter vs grey matter
White Matter: Few cell bodies, and mostly bundles of myelinated axons. Connects grey matter areas to each other.
Grey Matter: Predominately cell bodies with few myelinated axons
neuron classificaiton
- Dendrites:
Shape: - Stellate (starshaped)
- Pyramidal (aspinous)
Spine: - Spinous (has spine)
- Aspinous (doesn’t)
- Axons Length:
- Golgi type I – long “internuncial”
- Golgi type ll- small ‘interneurons’
- Number of Neurites (Cell bodies)
- Multipolar
- Unipolar
- Bipolar
possible synaptic arrangements
axodendritic
axosomatic
axoaxonic
afferent vs efferent neurons
Afferent: to the connection (in)
Efferent: form the connection (out)
glial cells
Astrocytes: cells that guide the migration of neurons and the growth of axons and dendrites during embryological devilment. Wrap around the synapses of functionally related axons. Make up the majority of cells in the human central nervous system.
microglia, cells that remove waste material and other microorganisms from the nervous system. Primary immune cells of the central nervous system. Contribute to learning through removing the weakest synapse
Oligodendrocytes: responsible for myelin sheath formation.
Schwann Cells (only in the PNS): surround neurons keeping them alive and covering them with a myelin sheath. Development, maintenance function and regeneration of peripheral nerves.
Radial Gilia: Cells that guide the migration of neurons and the growth of axons and dendrites during embryological development
blood brain barrier
- Physical Barries: tight junctions most substances from freely passing between the blood and the brain tissue.
- Selectively Permeable: certain molecules pass through
* Small, lipophilic (fat-soluble) molecules like oxygen and carbon dioxide, pass through easily
* Large or hydrophilic (water-soluble) molecules, pathogens, and toxins are blocked.
* Active transports allow passage for select molecules e.g. glucose, amino acids
endothelia cells line the walls of the blood brain barrier
line the walls of the blood brain barrier
is a lipid based outer membrain
Nourishment of Vertebrate Neurons
- Neurons depend almost entirely on glucose, as it is the only nutrient that crosses the bbb
- The brain uses 20 of its oxygen and 25 of its glucose
- To use glucose the body, need vitamin b, thiamine. Thiamine defect as present in chronic alcoholism.
Resting Membrane Potential
- Plasma membrane around the neuron
- Allows uncharged molecules through using the sodium–potassium pump 3 sodium(NA) out two in potassium (K) 3:2 ratio
sodium–potassium pump: mechanism that actively transports sodium ions out of the cell while drawing in two potassium ions
electrical gradient
electrical gradient: the difference in electrical charge between two adjacent areas.
if an area is negative, posotive ion will flow to it.
concentration gradient
the difference in concentration of a particular ion between two adjacent area. if an area has many K+ ion, the K+ ion will flow to an area will less.
resting memebrain potential process
K+ channels: open when the neuron is at rest, K* ions flow into the cell driven by electrical gradient and out of the cell driven by chemical gradient
* Na/K pumps: actively (i.e. with energy) pump Na* out of and K+ into the cell on a 3:2 ratio
* Na* channels: only open at limited voltages. When open Na* will flow into the cell along the chemical and electrical gradient
* Voltage-gated K* channels: would allow K+ ions into and out of the cell, except only open when the cell potential is positive (i.e. not at rest)
diffusion
Diffusion is the movement of particles from a high to lower concentration. Osmosis is the diffusion of water across a membrane.
Facilitated diffusion is a type of diffusion in which the molecules move from the region of higher concentration to the region of lower concentration assisted by a carrier.
myelin
o Myelin (oligodendrocytes: glial cells) insulates the axon in order for the signal to travel down the neuron.
o The small gaps in-between the myelin is called the Nodes of Ranvier
(EPSP) vs (IPSP)
Excitatory Post Synaptic Potential (EPSP) Communication with dendrites from other neurons can bring positive ions into the cell Positive ions produce a small depolarisation - an Excitatory Post Synaptic Potential Small EPSPs are not enough to produce an action potential
- Inhibitory Post Synaptic Potential (IPSP) Communication with dendrites from other neurons can bring negative ions into the cell Negative ions produce a small hyperpolarisation - an Inhibitory Post Synaptic Potential IPSPs will not produce an action potential (pushes potential down)
depolarisaton vs hyperpolarisation
dep: -80mv to -65mv
hyper: -80mv to -95mv
voltage gated sodium channels
- Voltage sensors are enriched in positively charged amino acids
- The presence of these charges makes them sensitive to the membrane potential. The voltage sensors are pulled towards the negatively charged surface
- These are attached to the pore forming domain and pull the gate open or closed depending on what side the negative charge is on.
- Inactivated state: gates enter the inactivation state in 1msec after open
- Is powered by ATP adenosine triphosphate
Voltage gated potassium channels:
- Lack the inactivation gate
- This is why it takes longer for the channels to close.
Neural intergration
IPSP and EPSP can cancel each other out A small depolarisation (EPSP) will cancel the effect of a small hyperpolarisation (IPSP)
sherrington
Sherrington introduced the term synapse
Other observations: * Several weak stimuli presented at nearby places or time produce a stronger reflex
- When one set of muscles become excited, a different set becomes relaxed (inhibitory synapses)
electrical synapse
- Junction is specialised so that it is only a small distance (3.5 nm) between cells (20nm)
- Is faster than chemical synapse and allows neurons to act as if they where one
- Coordination and breathing
chemical synapse
- Junction is specialised so that it is only a small distance (3.5 nm) between cells (20nm)
- Is faster than chemical synapse and allows neurons to act as if they where one
- Coordination and breathing
ionotropic recepotrs
- Ligand gated ion channel;
- Binding of Ach or Glu lets positive ion into cell (Na, Ca): Stimulatory/Excitatory
- Binding of GABA les negative ions into cells (Cl): Inhibitory
Metabotropic Receptor
- Single polypeptide: 7 membranes spanning domines
- Each is has a (a) helix where neurotransmitters can bind
G proteins: - Three subunits: y,a,B
sequence of action in metabotropic receptors
Sequence of events:
- Inactive the a subunit of the G-protein binds to Guanosine Diphosphate (GDP)
- Neurotransmitter binds to receptor
- The subunits split between the B and a subunits if GTP is bound to the subunit
- The subunit then activates different effector proteins
- Second messenger cascades are activated
- The B subunit opens ion channels and the a subunit creates a second messenger cascade.
different functions of ion and meta receptors
For vision and hearing, the brain needs rapid, up-to-date information, the kind that ionotropic synapses bring. In contrast, metabotropic synapses are better suited for more enduring effects such as taste (Huang et al., 2005), smell, and pain (Levine, Fields, & Basbaum, 1993),.
g proteins
- Many receptors are linked to inhibitory G-proteins which prevent the second messenger cascade.
Auto receptors:
- Receptors that are located pre synaptically
- This provides feedback to the presynaptic neuron to stop releasing neurotransmitter
Broad types of Neurotransmitters:
Amino Acids – acids containing an amine group (NH2)
Acetylcholine – similar to amino acids, but containing a N(CH3)3 group
Monoamines – formed in a certain way from amino acids
Peptides – chains of amino acids (Substance P) ), similar to
molecular make up if proteins
Lipids – (e.g. Anademide
Purines (e.g. adenosine)
Soluble gases (e.g. Nitric Oxide0 - dilates the nearby blood vessels when realised
peptides
peptides - made in the soma
Neuron synthesizes a precursor peptide (small protein) synthesised in Rough Endoplasmic reticulum
2. Cleaved (split) in Golgi apparatus to active neurotransmitter
4. Secretory vesicles bud off from Golgi apparatus
5. Secretory granules (large vesicles, 100 nm) transported to terminal and stored
Monoamines, amino Acids & Acetylcholine
Are made from precursor molecules in the terminal and are transport into synaptic vesicles.
1. Precursor molecule (form diet) synthesised to neurotransmitter (mostly amino acids)
2. Transported to synaptic vesicle (50nm) and stored
amino acids
Glutamate:
* Major excitatory NT
* Learning & Memory
* Neuroplasticity
* Excitotoxicity
GABA:
* Major inhibitory NT
* Modulates various processes
Glycine:
- Brain stem, spinal cord
- Inhibitory
Acetylcholine:
- Memory
- Perceptual Learning
- Movement
- REM sleep
- Interneurons are either cholinergic or GABAergic
Monoamines:
Dopamine:
* Short term memory
* Strategy & planning
* Reward- wanting
* Movement- loss of dopaminergic neurons leads to Parkinson’s
Serotonin:
* Cognition
* Emotion
* Reward
Noradrenaline:
* Attention
* Flight/ Fight
* Sleep
interneuron
- An interneuron project the signal onto another neuron in a different brain area to regulate the stimulus.
gaba :
s- is naturally found in out diet and is often a precussor
m- is recyled or taken into a glial cell
acetycholine location
- Majority of Cholinergic cells (Acetylcholine) are found in the nucleus basalis, medial sectile and forebrain. receives input from the hypothalamus.
Acetylcholine pathways
- nucleus basalis into the cortex.
- Septohippocampal pathway:
acetylcholine synthesis/ metabolisum
s- acetyl co- a + choline= acetycholine and conezyme A
m- - Acetylcholine is broken down by Acetylcholine Esterase (AChE)
- Occurs in synaptic cleft and is broken into choline and Acetic Acid
- Choline is then transported into the presynaptic cleft for reuse
more choline detected in the synpatic cleft= reduces ACh
Monoamines:
Catecholamines (3):
- Dopamine
- Noradrenaline (norepinephrine)
- Adrenaline (epinephrine) Hormone form kidney
Indolamines (3):
* Serotonin (5-HT): activated during sunlight
* Melatonin: circadian rhythms (sleep)
* Histamines
dopamine pathways
Nigrostriatal system: Substantia nigra > to striatum: Important for reward
Mesolimbic system: ventral tegmental area > nucleus accumbens: Important for moment
Mesocortical pathway: Mesolimbic system> into the frontal cortex
Mesocorticalimbic pathway: both the Mesolimbic and Mesocortical
noradrenaline cell bodies
Causal raphe nuclei
Locus coeruleus
Monoamine syntheses (Catcholamine)
> L-DOPA
> Dopamine
> Noradrenaline
> adrenaline
serotoin cell bodies
Causal raphe nuclei
Locus coeruleus
serotonin synthesis
> Tryptophan
5-Hydroxytryptophan
5-Hydroxytryptamine
(Serotonin, 5-HT)
Tryptophan is an amino acid Found in grains, meat & dairy
Neuropeptides
What they are
Neuropeptides are short chains of amino acids that are released by neurons. They are synthesized in the cell soma and transported down the axon.
What they do
Neuropeptides regulate a wide range of behaviors, including feeding, pain sensing, reproduction, sleep–wake cycles, and immune responses
drugs and effect on neuro transmission
Cocaine and amphetamine: They block reuptake of released dopamine, serotonin, and norepinephrine.
Hallucunogenic durgs: chemically resemble serotonin (see Figure 2.17). They attach to serotonin receptors and provide stimulation at inappropriate times or for longer-than-usual durations.
Opiate: neuropeptides, now known as endorphins (a contraction of endogenous morphines), that bind to the same receptors as endorphins.
Nicotine: nicotinic receptors are abundant on neurons that release dopamine, nicotine increases dopamine release
Cannabinoids: bind to anandamide or 2-AG receptors on presynaptic neurons, indicating, “The cell got your message. Stop sending it.” The presynaptic cell, unaware that it hadn’t sent any message at all, stops sending.
Depression and Biology:
- gene controlling the serotonin transporter are more likely than other people to react to stressful experiences by becoming depressed. However, absence of stressful experiences, their probability is not increased.
Abnormalities in hemispheric Dominance:
strong relationship between happy mood and increased activity in the left prefrontal cortex
Neurotrophins aid in the survival, growth, and connection of neurons.
- People with depression often have lower level of neurotrophins brain derived neurotrophic facture (BDNF)
Elcotroconvulsive theroapy
Electroconvulsive therapy: a treatment for depression by electrically inducing a seizure
SAD
(seasonal affective disorder) : Many people with SAD have a mutation in one of the genes responsible for regulating the circadian rhythm
treatments:
bright light treatment: 2500 lux for a couple of hours each morning, or even brighter lights for a shorter time (Dallaspezia, Suzuki, & Benedetti, 2015; Pail et al., 2011).
deep brain stimulation: use of a battery-powered device implanted into a brain to deliver stimulation to certain areas
bipolar disorder
unipolar depression: normal and depression
bipolar depression: dpression normal and mania
Treatment:
Lithium stabilizes mood, preventing a relapse into either mania or depression. The dose must be regulated carefully, as a low dose is ineffective and a high dose is toxic.
Schizophrenia:
A severe mental disorder in which people interpret reality abnormally. They often have difficulty understanding abstract concepts, maintaining focus and memory impairments
Mild brain Abnormalities in Schizophrenia:
- including less than average gray matter, especially in the hippocampus, amygdala, and thalamus White matter is reduced, and the ventricles (fluid-filled spaces within the brain) are enlarged
Long -term: Parkinson’s Alzheimer’s
Neuroanatomy:
Brian has three major division:
the hindbrain, the midbrain, and the forebrain
Forebrain:
Thalamus, hypothalamus
Cerebral cortex, hippocampus, basal ganglia
Midbrain:
Tectum, tegmentum, superior colliculus, inferior colliculus, substantia nigra
Hindbrain:
Tectum, tegmentum, superior colliculus, inferior colliculus, substantia nigra
Anatomical Directions
- Coronal
- Sagittal
- Horizontal
Directions or axes:
* Rostral / caudal
* Dorsal / ventral
* Medial / Lateral
- gotta print more from word doc
CSF
- Cerebral Aqueduct
- Two lateral ventricles
- Third ventricle
- Fourth ventricle
- Cerebrospinal fluid (CSF) produced in the choroid plexus (cells that line the ventricles). Flows through ventricles.
- CSF surrounds and protects the brain (meninges). Meningitis is the swelling of the meninges which is a thick outer layer of the. Swollen blood vessels in the meninges are responsible for the pain of a migraine headache (Hargreaves, 2007). (Hargreaves, 2007).
Meningie’s and the Subarachnoid Space
prosecting the brain and the spinal cord from mechanical trauma and injury. Distributes the forces that occur during head movements or impacts
PNS
- Dorsal roots connect to skin (sensory nerves)
- Ventral roots connection to muscle
(skin in muscle out)
sympathetic nerouse system vs parasympathetic
Sympathetic - Prepared to body for action
Parasympathetic - non emergency (digestion, growth, immune responses, energy storage)
Hormones:
- Hormone important for the nervous systems controlled by the hypothalamus and pituitary gland.
anterior Pituitary and Posterior
GH - growth hormone
ACTH - adrenocorticotropic hormone -> adrenal gland
TSH - thyroid secreting hormone -> thyroid gland.
FSH-follicle-stimulating hormone - ovaries/testes
LH - luteinizing hormone -> ovaries
Prolactin - mammary glands
Posterior Pituitary:
- Vasopressin – essential role in osmotic balance
- Oxytocin – love hormone
Primary motor cortex:
- Execution, regulation and coordination of movements on the opposite side of the body
- Somatotopic organisation: pot for point correspondence of an area of the body specific point on the central nervous system.
Precentral gyrus:
- the posterior portion of the frontal lobe of the cortex, specialized for control of movement
Premotor Cortex:
- Preparing and executing limb movements
- Selection of appropriate movements
- Learning
- Social Cognition
- Mirror neurons: active when observing someone’s else performing an action
Prefrontal Cortex:
Posterior zone:
* Movement
Middle zone;
* Attention
* Working memory
* Prospective memory
* Temporal memory
Anterior Zone:
* Decision making
* Planning
* Problem solving
* Language
* Self Control
temporal lobe - auditroy function superior temporal gyrus
- Primary auditory cortex – processes and integrates auditory stimuli
- Language recognition
- Tonotopic map: certain cells prefer particular tones ( has a similar makeup to the somatotopic layout in that particular cells correspond to particular tones.)
occipital lobe function
Primary visual cortex (V-1)
* Receives input retina via the lateral geniculate bodies
* First stages of visual processing – responsive to simple properties e.g. oriental, spatial frequency, edge detection
High visual areas (V2-6)
* Proves more complex features: colour curves
* Integrate information
- Cortical blindness: damage to the occipital lob causing blindness
Parietal Lobe Functions:
: section of the cerebral cortex between the occipital lobe and the central sulcus
receives sensations from touch receptors, muscle-stretch receptors, and joint receptors.
Limbic System:
parts:
cingulate gyrus
thalmus
hypothalamus
mamillar body
hippocampus
amygdala
olfactroy bulb
Important for processing emotional stimuli
Critical for learning and memory
Amygdala
- Important for processing emotional stimuli
- Urbach-Weith’s disorder; calcification of the skin. Patient SM had damage calcification of the amygdala and had not respond to things naturally found to induce fear. Snake, spider, held at gun point
- Kluver-Busy syndrome; a behavioural disorder caused by temporal lobe damage
Hippocampus:
- Long term episodic memory: memory for specific events
Engram’ cells have been identified in the hippocampus. These encode:
* Specific objects (place cells)
* Locations in space (grid cells)
* Location in time (time cells)
Cingulate Gyrus:
- Important for processing pain and emotional pain
- Activated in response to empathetic pain
- Damage does not prevent the sensation of pain, but the pain is not distressing
The Basal Ganglia:
- Important for movement, cognition and motivation
- Parkinson’s disease: degeneration of the dopamine neurons that synapse onto the basal ganglia.
Caudate and Putamen:
- Terminal of the midbrain dopaminergic neuros (from ventral tegmental area and substantia nigra)
- Dorsal stream come from the substantia nigra to the dorsal striatum, important for movement
- Ventral stream going form the VPA to the putamen, important for reward processing
- Nucleus accumbens
- Nucleus accumbens is particularly important from motivated responding
- Importance in substance use disorders
Globus Pallidus:
- Part of the relay system between the striatum and the thalamus. Inhibitory neuros passed from striatum to globus pallidus meanies binding neuros
- Important for regulation of voluntary movement
- Loops between striatum, globus pallidus and thalamus form the indirect pathway
Declarative:
epidosic and semantic
Nondeclarative
- Implicit (memory without awareness; past experience influences current task – procedural memory)
- Procedural: cerebellum (muscle response, striatum (habits, skills) & amygdala (emotional response)
Procedural (learning a motor procedure in response to sensory input) - Non-associative learning: change in behavioural response to a repeated stimulus (e.g. Habituation & sensitisation)
- Associative learning: forming associations between events (e.g. classical conditioning & instrumental conditioning)
red nucleus
red nucleus prevents response but not learning
neuro geneisis/ stem cell
- found in the subependyma of teh ventricular system
Migration of these new neurons are helped by the ependymal cells - A lot of neurogenesis also occurs in the dentate gyrus of the hippocampus
Neuroplasticity:LTP
- Long Term Potations = enchantment of synapse strength
- Strengths= ability to produce EPSP to promote action potentials
CBT: in Dendritic growth
- CBT can also produce reorganisation of our ‘neural circuits”
Learning form Aplysia – Eric Kandel
- Aplysia have been used extensively to study the neuroplasticity associated with sensitisation and habituation by investigating their gill withdrawal reflex
Components to create LTP
- Specificity
If some of the synapses onto a cell have been highly active and other have not only the active ones with be strengthened. - Cooperativity
Nearly simultaneous stimulation by two or more axons produces LTP more strongly that does repeated stimulation by just one axon - Associativity
Pairing a weak input with a strong input enhances later response to the weaker input.
types of glutamate ionotropic receptors
lonotropic: NMDA (N-methyl-D-aspartate)
AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid) lonotropic:
Kainate receptors
Metabotropic (mGluR1 - mGluR7) - linked to second messenger systems
processes of NMDA recepotor activation
- inilatlly blocked by magnesium
- glutamate also binds to AMPA recepots and start to polarise the dendrite
- Once the charge in the neuron becomes a (ESP) magnesium in NMDA receptors begins to be displaced leading to calcium entering the neuron.
- This then becomes a large excitatory response
Long Term Potentiation (Strengthening) (LTP)
AMPA ionotropic: lets in sodium
- NMDA R metabotropic : when enough is in to depolarize the membrane the magnesium and lets in calcium
High levels of Ca entry into cell upregulates Calcium-calmodulin-dependent protein kinas 11 (CAMK2) and Protein Kinase C (PKC)
When CAMK2 is activated it sets in motion a series of reactions leading to release of a protein called CREB- cyclic adenosine monophosphate.
CREB does to the Nucleus of the cell and regulates the expression of several geners.
BDNF: Persisting activity at synapses leads to action potentials that start in axons but back-propagate into the dendrites, which then release BDNF
Long Term Depression (weaking)
- BCM theory: synapses that are active when the cell Is only weakly depolarized (i.e. only small EOSO, not action potential) will become weaker.
Striatum and Memory:
Learns gradually over many trials
Habits
Generally requires
prompt feedback
Implicit
Impaired learning of skills and habits
Memory Loss in Alzheimer’s Disease
- Apraxia - loss of ability to co-ordinate movements
- Aphasia - loss of ability to articulate ideas and comprehend written/spoken word
- Agnosia - cannot interpret sensory stimuli
- Patients with Alzheimer’s Disease have reduced Acetylcholine (ACh)
- Acetylcholine is prevalent or projects to brain regions involved in memory
Acetylcholine binds to two (cholinergic) receptors subtypes
* Nicotinic , Muscarinic
* The muscarinic antagonist atropine can disrupt memory processing
* Atropine has also been shown to inhibit the process of neurogenesis
why do we take drugs
- increase of dopamine in the nuclues accumbens
Dopamine relsea with expect reward
- The anticipation of reward produces a large increase in dopamine
- The reward itself produces some dopamine release, yet an error in the value of the reward has more of an effect on dopamine
- “better than expected” enhances dopamine signalling – drugs always do this through their ability to artificially produce dopamine plus the expected reward dopamine
Effect of stimulants
Ecstasy (MDMA) is also an ENTACTOGEN (touchy feely)
Amphetamines contain methal groups in their chemical structure. *Methal groups make chemicals fat loving. Fat loving chemicals cross membranes really easily.
Pharmacology of Cocaine.
Methamphetamine links dopamine receptors
- Dopamine is normally recycled through transporters specifically the vesicular monoamines transporter
- If not recycled it get broken down
Cocaine blocks transporters. Modulation of DAT increases dopamine in synaptic cleft DAT = dopamine transporter
This is the reason for the depressive like symptoms after taking ecstasy.
Pharmacology of Amphetamines
Amphetamines increase extracellular monoamines
Reverse monoamine and vesicular transporters (VAT)
Methamphetamine reverses the DAT & VMAT, inhibits monoamine oxidase (MAO)
“Ecstasy”
(a type of amphetamine
reverses the SERT(SERotonin Transporter)
pharmacology of cannabis and nicotin
Cannabinoid receptors: CB1 and CB2 Anandamide binds to these natural receptors. It is a natural ligand for these receptors.
Nicotine – Acetylcholine
Alcohol – GABA-A receptor agonist
NMDA glutamate receptor antagonist
Modulates opioid peptide system (mu receptors)
What is substance use disorder?
A compulsion to take drugs continuously or periodically
* Experience rewarding effect (A)
* Avoid the discomfort of its absence (B)
Incentive-sensitization theory of addiction
- Terry Robinson & Kent Berridge -1993
- Can change homeostasis
- Compulsive drug use & inability to stop (relapse)
- ‘Excessive amplification’ of wanting the drug
- Less reliance on ‘liking’ the drug
4 main components
* Addictive drugs share the ability to cause enduring adaptations
* Neural adaptations occur in regions involved in incentive motivation and reward (mesolimbic/ mesocortical)
* These regions become hypersensitive (sensitized
* But instead of sensitizing the reward (liking) component, drug ‘wanting’ is now dominate. The brain has changed to accommodate maladaptive behaviour
reptitive effect of cocaine and amphetamine
Nucleus Accumbens: Motivation, Reward & Reinforcement
Hippocampus & Amygdala: Memory & Emotion Dorsal
Striatum: Decisions & Habit formation
Prefrontal Cortex: Decisions & Control (appropriate behaviour)
Orbitofrontal Cortex: Drive (value of reward)
dorsal PFC
if pfc neuron are inhibtied it reduced glutame in the nucleus accubens and stops craving
Stops Liba pressing which stops craving
