CNS 2 Flashcards
How are seizures characterised by
The location of the abnormal activity and how it spreads
What is the focus of a seizure
Where it starts
What is a seizure
Abnormal firing of neurons
What is a partial seizure
Limited to a particular part of the brain
What is a generalised seizure
Involves both hemispheres of the brain
What are simple generalised seizures
Do not include the loss of consciousness
What are complex generalised seizures
Always include loss of consciousness
What are the causes of seizures
Change in blood glucose levels, pH levels, stress, fatigue, flashing lights
How can seizures be induced
Head injuries, lesions in the brain, tumours in the brain, infections, genetic components
How can you diagnose seizures
ECGS
What gives rise to different types of seizures
Mutations in iron channels
What is kainite
Normal agonist for glutamate receptors
What occurs in the kindling model
Occurs in patients that have reoccurring seizures, repeated low level electrical stimulation over several weeks
How can you treat seizures
By increasing inhibitory transmission or decreasing exhibitory transmission
How can we inhibit neurotransmission
We can affect the uptake of GABA from the synapse or we can deal with the metabolism of GABA
When are benzodiazepines and barbiturates used and example
In emergency situations for example Status epilepticus
An example of an uptake inhibitor
Tiagabine
An example of a metabolic inhibitor
Valproate
What does GAD do
converts glutamate into GABA
What occurs in GABAergic neurons
An enzyme is expressed known as glutamic acid decarboxylase
How can we decrease excitatory neurotransmission
Limiting the release of glutamate or decreasing the activity of the glutamate receptors
What is the most widely used drug to treat epilepsy
Carbamazepine
How do absence seizures work
They use a sub type of voltage gated calcium channel known as T-Type
What drugs can treat absent seizures
Ethosuximide and valproate
What do GABApentin and pregabalin drugs do
They limit the number of calcium channels in the membrane
What are some neurotransmitters in the brain
Noradrenaline, dopamine, 5-hydroxytryotamine, acetylcholine
What are amine neurotransmitters in the brain associated with
High level behaviours, cognition, emotion and awareness
What to antipsychotics manage and target
Schizophrenia and target dopamine
What to antidepressants manage and target
Depression and target 5-Hydroxytrpatamine
What’s the main source of noradrenaline
Locus sereleous
What type of receptors detect noradrenaline
G- coupled
What are Alpha1 receptors involved in
Motor control
What are Alpha 2 receptors involved in
Central regulation of blood pressure
What is B1 important for
Its a part of the brain important for initiating movements
What is the hippocampus involved in
Memory and learning
What type of receptor is Beta adreno and what does it do
A GS coupled receptor and inhibits the production through cyclic AMP
What type of receptor is Alpha 2 and what does it do
GI coupled receptor and inhibits the production of cyclic AMP
What type of receptor is Alpha 1
A GQ coupled receptor and increases phospholipase c signalling
What is dopamine important for
For fine motor control
What amino acid is dopamine made from
Tyrosine
What are the mesocritical and mesolimbic pathways involved with
Pleasure and reward, related to motivation
What enzyme converts dopa into dopamine
DOPA decarboxylase
Which two enzymes do dopaenergic neurons express
Tyrosine hydroxylase and DOPA decarboxylase
What are D1 and D5
GS coupled receptors, stimulating adenylate cyclase
What are D2, D3 and D4
GI coupled receptors, inhibits Adenylyl cyclase
What are D2 receptors known to do
Activate potassium channels and voltage gated calcium channels
What does an inhibition of D2 receptors lead to
Increased prolactin secretion
Where are D1 receptors widely expressed
In the cortex and limbic system
What are the therapeutic uses of amphetamine
Stimulates wakefulness, effective in treating ADHD
What are the positive symptoms of schizophrenia
Hallucinations, delusions, defects in ability to focus, aggression
What are the negative symptoms of Schizophrenia
Blunting of emotion, anhedonia, reluctance to perform every day tasks
What are effective treatments for schizophrenia
Agonists of D2 receptors
Types of Unipolar depression
Reactive (75%), and endogenous (25%)
What is bipolar disorder
Depression that alternates with mania characterised by excessive exurbance etc.
Typical symptoms of depression
Low mood, apathy, changes in weight/ appetite, low self esteem, lack of concentration, loss of libido
Diagnosis for depression
Patients experience symptoms for more than 2 weeks and they disrupt normal social and occupational function
Risk factors for depression
Genetic risks (40%), secondary to illness, stressful life events
Parts of the brain that impact depression
Amygdala, hippocampus, nucleus succumbence, ghrelin and leptin receptors
What can postnatal depression lead to
Depressed children, babies brain waves can become altered if mother is depressed
What kind of treatment is advised for people with depression
Counselling with the combination of antidepressants
What are the animal models of depression
Acute stress models, chronic (mild) stress models
What was the first antidepressant
Iproniazid- an MAO inhibitor
Which drugs exert their actions by manipulating monoamine neurotransmitters in the brain
Tricyclic ADs, Reserpine, Iproniazid
