Intro to Schizophrenia Flashcards
In 1898, Kraeplin used the term dementia praecox when describing psychosis. What did this mean?
dementia- disruption of cognitive and perceptual processes
praecox-early adulthood onset
Who was the first to describe illness as progressive with no return to premorbid functioning?
Kraeplin
Who reformulated the term dementia praecox and coined it schizophrenia?
Bleuler (1911)
Give examples of type 1 positive symptoms of schizophrenia.
delusions, hallucinations, thought disorder
Give examples of type 2 negative symptoms of schizophrenia.
anhedonia, flattened affect, avolition and alogia.
Liddle identified 5 syndrome categories. What were they?
- psychomotor poverty
- reality distortion
- disorganisation
- psychomotor excitation
- anxiety/depression
What are some cognitive symptoms of schizophrenia?
working memory, executive dysfunction and attentional deficits
Frontal cortex brain activation is ____ during executive tasks in schizophrenia.
lower
The dopamine theory of schizophrenia states that schizophrenia results from…?
hyperactivity in mesolimbic dopamine which gives rise to positive symptoms. Hypoactivity of dopamine in the frontal cortex gives rise to negative symptoms.
Brain dopamine turnover can be reflected by what concentration?
HVA plasma concentrations. Chronic antipsychotic drugs lower this.
Latent inhibition is disrupted by which drug that causes psychosis?
amphetamine
Which drugs can reverse the effects of amphetamines?
haloperidol and clozapine
Other than dopamine, which other neurochemicals have been related to schizophrenia?
glutamate, serotonin and GABA
Which neurotransmitters are amino acids?
glutamate and GABA
Which neurotransmitters are biogenic amines?
acetylcholine, serotonin, dopamine and adrenaline
Which neurotransmitter is the major excitatory neurotransmitter?
glutamate
Glutamate is synthesised from ______ in astrocytes.
glutamine
Glutamate is removed from the synapse by___?
glutamate transporters
Where is glutamate?
Glutamate is found in many areas of the brain, some of which include: VTA, striatum and PFC.
What are some of the glutamate receptors?
NMDA, AMPA & Kainate and Metabotropic
Is glutamate ionotropic or metabotropic? Explain why.
Glutamate receptors are ionotropic which means they are ligand-gated ion channels that are fast acting once a ligand binds.
Dopamine receptors are metabotropic which means….
They don’t have channels that open or close. Instead they have G-proteins attached which act as secondary messengers. This makes metabotropic receptors slow acting.
The Glutamate hypothesis predicts that schizophrenia may be caused by ____
reduced function of NMDA receptor which results in reduced glutamate transmission
What would you predict the drugs phencyclidine and ketamine ( NMDA antagonists) do?
they produce positive and negative symptoms of schizophrenia
How did the Glutamate hypothesis come about?
In 1980, Kim discovered reduced glutamate in cerebrospinal fluid of patients with schizophrenia.
What is the relationship between dopamine and glutamate?
Glutamate regulates dopamine function. The release of dopamine is dependent on activation of NMDA receptors on these neurons.
The dopaminergic pathway starts at ___ and ends at _____.
From the VTA to the Nucleus accumbens.
The glutaminergic pathways starts at ____ and ends at ____.
From the VTA to the PFC
According to the dopamine hypothesis, how are cognitive and negative symptoms caused?
hypoactivity of dopamine in the mesocortical pathway ( VTA to the PFC).
According to the dopamine hypothesis, how are positive symptoms caused?
an overactivity of dopamine in the mesolimbic pathway( VTA to the nucleus accumbens)
The D1 and D5 receptors _____ adenylate cyclase.
Whilst D2, D3 and D4 receptors ______ adenylate cyclase.
activate
inhibit
Where are D1 receptors mostly located in the brain?
cerebral cortex
Where are D2 receptors mostly located in the brain?
striatum
What are agonists?
Drugs that occupy receptors and activate them.
What are antagonists?
Drugs that occupy receptors but do not activate them due to the shape being different from the original neurotransmitter.
Most drugs used to treat schizophrenia are D2 _____
antagonists
Parkinsonian side effects of antipsychotics are caused by D2 antagonists in the _____ activating cholinergic cells.
striatum
A correlation between antipsychotic drug binding to dopamine receptors and ______
clinical effectiveness.
Pre-pulse inhibition and latent inhibition are disrupted by amphetamine and enhanced by _______
antipsychotic drugs
