Schizophrenia

Question 1

prevalence of schizophrenia worldwide ?

Answer 1

1%

Question 2

what types of symptoms do schizophrenics have ?

Answer 2

positive
negative
cognitive

Question 3

what are the positive symptoms of schizophrenia ?

Answer 3

hallucinations
disorganised speech and behaviours
delusions

Question 4

what are the negative symptoms of schizophrenia ?

Answer 4

adhedonia
social withdrawal
affective flattening
avolition

Question 5

what are the cognitive symptoms ?

Answer 5

impaired working memory
diminished executive function
difficulty focusing

Question 6

schizophrenics loose contact with what ?

Answer 6

reality

Question 7

diagnosis ?

Answer 7

Two or more of the following, each present for a significant portion of
time during a 1-month period (or less if successfully treated). At least
one of these should include 1, 2 or 3.

1. Delusions
2. Hallucinations
3. Disorganised speech
4. Grossly abnormal psychomotor behaviour
5. Negative symptoms

Social/occupational dysfunction
• Exclusion of schizoaffective and major mood disorders
• Exclusion of substance-related disorders

Question 8

what is believed to be the cause of schizophrenia ?

Answer 8

mix of genetic and environmental factors

Question 9

environmental factors believed to contribute to the development of schizophrenia ?

Answer 9

paternal age
maternal stress
prenatal
infection/immune activation,
 malnutrition,
hypoxia-related obstetric complications,
childhood/adolescence social stress 
cannabis abuse

Question 10

Two sensitive time periods during life where exposure to adverse effects could lead to schizo ?

Answer 10

early brain
development and maturation during adolescence have
been identified as particularly sensitive periods for
exposure to adverse environmental event

Question 11

when is the first psychotic episode ?

Answer 11

mid 20’s

Question 12

which sex is more affected by schizophrenia ?

Answer 12

males

Question 13

brain images reveal enlarged what in schizo patients ?

Answer 13

ventricles

Question 14

How do inhibitory NT density in patients compare to controls ?

Answer 14

more inhibitory NTs before ages of 40 before controls and then less after this age

Question 15

How does the density of excitatory NTs in patients compare to controls ?

Answer 15

before the age of 70 patients have a higher density of excitatory NTs

Question 16

what structural chnages are seen in the hippo c of schizophrenics ?

Answer 16

disorganised pyramidal cells - correlates to disease severity

Also in entorhinal, cingulate, parahippocampal cortex

Question 17

DA hypothesis of shizophrenia ?

Answer 17

dopamine hypothesis of schizophrenia
proposes that a combination of decreased
cortical and increased subcortical dopaminergic
neurotransmission underlie the disorder.

Question 18

5HT hypothesis ? two pathways

Answer 18

dorsal raphe nuclei -> substantia nigra

rostral raphe nuclei ascending into the cerebral cortex, limbic regions and basal ganglia

The up-regulation of these pathways leads to
hypofunction of the dopaminergic system, and
this effect may be responsible for the negative
symptoms of schizophrenia

Clozapine works mainly by modulating
serotonergic neurotransmission

LSD = hallucinations

Question 19

what receptor does clozapine target ?

Answer 19

5HT1A antagonism

nasty side-effects - agranualosis - blood condition
used for treatment resistant schizophrenia

Question 20

what is PCP and what does admin in rats cause ?

how can this be reversed ?

Answer 20

NMDA antagonist - dysfunction in memory
treat with probiotics - corrects memory deficits

related to gut microbiome

Question 21

what are face, predictive and construct validity ?

Answer 21

face - does the model mimic the core behavioural symptoms

construct - does the model have the sam neurochemical and structural defects

predictive - will the model be useful in revealing new information about the disease and does it respond to treatments that are already available for the human condition

Question 22

animal models of schizophrenia ?

Answer 22

Prepulse Inhibition Deficits induced by
 Apomorphine
 PCP
 Amphetamine
 MK-801

Conditioned Avoidance Test
Latent Inhibition
Social Withdrawal following
 PCP, MK-801
 Amphetamine

Early Life Manipulations
 Neonatal Ventral Hippocampal Lesions
 Isolation Rearing
 Neonatal administration of MAM

Question 23

what is prepulse inhibition ?

Answer 23

Prepulse inhibition (PPI) of the startle reflex is an useful model to assess the inability to
process information seen in schizophrenia

The startle response is a brainstem reflex elicited by the sudden presentation of a sufficiently
intense stimulus observed in most mammalian species.

Startle reflex is proposed to have evolved as a defensive response (Davis, 1984) because of the
protective nature of the behaviour patterns consisting of eyelid closure, limb flexion and a
transient increase in sympathetic output

Question 24

descrice PPI test

Answer 24

rat placed in a box on a platform sensitive to movement
a loud sound is played and the startle response is recorded
Next a soft sound is played before the loud sound, in controls the startle reflex is dampened by the softer sound. this is prepulse inhibition

Question 25

how does MK801 affect PPI ?

Answer 25

decreases it | this can be reversed by admin of cannabidiol

Question 26

whats lateral inhibtion ?

Answer 26

Latent inhibition (LI) is a process of learning to ignore irrelevant stimuli and is manifested as slower learning about a stimulus that has been pre-exposed without consequence (PE), compared to learning about the same stimulus without pre-exposure (NPE)

Question 27

TLR2 deficit mice show

Answer 27

recognition memory deficits - cant differentiate between novel and old mice